| 1 | greg | 2.1 | #ifndef lint | 
| 2 | greg | 2.7 | static const char RCSid[] = "$Id: gendaymtx.c,v 2.6 2013/01/25 23:17:31 greg Exp $"; | 
| 3 | greg | 2.1 | #endif | 
| 4 |  |  | /* | 
| 5 |  |  | *  gendaymtx.c | 
| 6 |  |  | * | 
| 7 |  |  | *  Generate a daylight matrix based on Perez Sky Model. | 
| 8 |  |  | * | 
| 9 |  |  | *  Most of this code is borrowed (see copyright below) from Ian Ashdown's | 
| 10 |  |  | *  excellent re-implementation of Jean-Jacques Delaunay's gendaylit.c | 
| 11 |  |  | * | 
| 12 |  |  | *  Created by Greg Ward on 1/16/13. | 
| 13 |  |  | */ | 
| 14 |  |  |  | 
| 15 |  |  | /********************************************************************* | 
| 16 |  |  | * | 
| 17 |  |  | *  H32_gendaylit.CPP - Perez Sky Model Calculation | 
| 18 |  |  | * | 
| 19 |  |  | *  Version:    1.00A | 
| 20 |  |  | * | 
| 21 |  |  | *  History:    09/10/01 - Created. | 
| 22 |  |  | *                              11/10/08 - Modified for Unix compilation. | 
| 23 |  |  | *                              11/10/12 - Fixed conditional __max directive. | 
| 24 |  |  | *                              1/11/13 - Tweaks and optimizations (G.Ward) | 
| 25 |  |  | * | 
| 26 |  |  | *  Compilers:  Microsoft Visual C/C++ Professional V10.0 | 
| 27 |  |  | * | 
| 28 |  |  | *  Author:     Ian Ashdown, P.Eng. | 
| 29 |  |  | *              byHeart Consultants Limited | 
| 30 |  |  | *              620 Ballantree Road | 
| 31 |  |  | *              West Vancouver, B.C. | 
| 32 |  |  | *              Canada V7S 1W3 | 
| 33 |  |  | *              e-mail: [email protected] | 
| 34 |  |  | * | 
| 35 |  |  | *  References: Perez, R., P. Ineichen, R. Seals, J. Michalsky, and R. | 
| 36 |  |  | *                              Stewart. 1990. ìModeling Daylight Availability and | 
| 37 |  |  | *                              Irradiance Components from Direct and Global | 
| 38 |  |  | *                              Irradiance,î Solar Energy 44(5):271-289. | 
| 39 |  |  | * | 
| 40 |  |  | *                              Perez, R., R. Seals, and J. Michalsky. 1993. | 
| 41 |  |  | *                              ìAll-Weather Model for Sky Luminance Distribution - | 
| 42 |  |  | *                              Preliminary Configuration and Validation,î Solar Energy | 
| 43 |  |  | *                              50(3):235-245. | 
| 44 |  |  | * | 
| 45 |  |  | *                              Perez, R., R. Seals, and J. Michalsky. 1993. "ERRATUM to | 
| 46 |  |  | *                              All-Weather Model for Sky Luminance Distribution - | 
| 47 |  |  | *                              Preliminary Configuration and Validation,î Solar Energy | 
| 48 |  |  | *                              51(5):423. | 
| 49 |  |  | * | 
| 50 |  |  | *  NOTE:               This program is a completely rewritten version of | 
| 51 |  |  | *                              gendaylit.c written by Jean-Jacques Delaunay (1994). | 
| 52 |  |  | * | 
| 53 |  |  | *  Copyright 2009-2012 byHeart Consultants Limited. All rights | 
| 54 |  |  | *  reserved. | 
| 55 |  |  | * | 
| 56 |  |  | *  Redistribution and use in source and binary forms, with or without | 
| 57 |  |  | *  modification, are permitted for personal and commercial purposes | 
| 58 |  |  | *  provided that redistribution of source code must retain the above | 
| 59 |  |  | *  copyright notice, this list of conditions and the following | 
| 60 |  |  | *  disclaimer: | 
| 61 |  |  | * | 
| 62 |  |  | *    THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESSED OR IMPLIED | 
| 63 |  |  | *    WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | 
| 64 |  |  | *    OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | 
| 65 |  |  | *    DISCLAIMED. IN NO EVENT SHALL byHeart Consultants Limited OR | 
| 66 |  |  | *    ITS EMPLOYEES BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | 
| 67 |  |  | *    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | 
| 68 |  |  | *    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF | 
| 69 |  |  | *    USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED | 
| 70 |  |  | *    AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | 
| 71 |  |  | *    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN | 
| 72 |  |  | *    ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | 
| 73 |  |  | *    POSSIBILITY OF SUCH DAMAGE. | 
| 74 |  |  | * | 
| 75 |  |  | *********************************************************************/ | 
| 76 |  |  |  | 
| 77 |  |  | /* Zenith is along the Z-axis */ | 
| 78 |  |  | /* X-axis points east */ | 
| 79 |  |  | /* Y-axis points north */ | 
| 80 |  |  | /* azimuth is measured as degrees or radians east of North */ | 
| 81 |  |  |  | 
| 82 |  |  | /* Include files */ | 
| 83 |  |  | #define _USE_MATH_DEFINES | 
| 84 |  |  | #include <stdio.h> | 
| 85 |  |  | #include <stdlib.h> | 
| 86 |  |  | #include <string.h> | 
| 87 |  |  | #include <ctype.h> | 
| 88 |  |  | #include "rtmath.h" | 
| 89 |  |  | #include "color.h" | 
| 90 |  |  |  | 
| 91 |  |  | char *progname;                                                         /* Program name */ | 
| 92 |  |  | char errmsg[128];                                                       /* Error message buffer */ | 
| 93 |  |  | const double DC_SolarConstantE = 1367.0;        /* Solar constant W/m^2 */ | 
| 94 |  |  | const double DC_SolarConstantL = 127.5;         /* Solar constant klux */ | 
| 95 |  |  |  | 
| 96 |  |  | double altitude;                        /* Solar altitude (radians) */ | 
| 97 |  |  | double azimuth;                         /* Solar azimuth (radians) */ | 
| 98 |  |  | double apwc;                            /* Atmospheric precipitable water content */ | 
| 99 |  |  | double dew_point = 11.0;                /* Surface dew point temperature (deg. C) */ | 
| 100 |  |  | double diff_illum;                      /* Diffuse illuminance */ | 
| 101 |  |  | double diff_irrad;                      /* Diffuse irradiance */ | 
| 102 |  |  | double dir_illum;                       /* Direct illuminance */ | 
| 103 |  |  | double dir_irrad;                       /* Direct irradiance */ | 
| 104 |  |  | int julian_date;                        /* Julian date */ | 
| 105 |  |  | double perez_param[5];                  /* Perez sky model parameters */ | 
| 106 |  |  | double sky_brightness;                  /* Sky brightness */ | 
| 107 |  |  | double sky_clearness;                   /* Sky clearness */ | 
| 108 |  |  | double solar_rad;                       /* Solar radiance */ | 
| 109 |  |  | double sun_zenith;                      /* Sun zenith angle (radians) */ | 
| 110 |  |  | int     input = 0;                              /* Input type */ | 
| 111 |  |  |  | 
| 112 |  |  | extern double dmax( double, double ); | 
| 113 |  |  | extern double CalcAirMass(); | 
| 114 |  |  | extern double CalcDiffuseIllumRatio( int ); | 
| 115 |  |  | extern double CalcDiffuseIrradiance(); | 
| 116 |  |  | extern double CalcDirectIllumRatio( int ); | 
| 117 |  |  | extern double CalcDirectIrradiance(); | 
| 118 |  |  | extern double CalcEccentricity(); | 
| 119 |  |  | extern double CalcPrecipWater( double ); | 
| 120 |  |  | extern double CalcRelHorzIllum( float *parr ); | 
| 121 |  |  | extern double CalcRelLuminance( double, double ); | 
| 122 |  |  | extern double CalcSkyBrightness(); | 
| 123 |  |  | extern double CalcSkyClearness(); | 
| 124 |  |  | extern int CalcSkyParamFromIllum(); | 
| 125 |  |  | extern int GetCategoryIndex(); | 
| 126 |  |  | extern void CalcPerezParam( double, double, double, int ); | 
| 127 |  |  | extern void CalcSkyPatchLumin( float *parr ); | 
| 128 |  |  | extern void ComputeSky( float *parr ); | 
| 129 |  |  |  | 
| 130 |  |  | /* Degrees into radians */ | 
| 131 |  |  | #define DegToRad(deg)   ((deg)*(PI/180.)) | 
| 132 |  |  |  | 
| 133 |  |  | /* Radiuans into degrees */ | 
| 134 |  |  | #define RadToDeg(rad)   ((rad)*(180./PI)) | 
| 135 |  |  |  | 
| 136 |  |  |  | 
| 137 |  |  | /* Perez sky model coefficients */ | 
| 138 |  |  |  | 
| 139 |  |  | /* Reference:   Perez, R., R. Seals, and J. Michalsky, 1993. "All- */ | 
| 140 |  |  | /*                              Weather Model for Sky Luminance Distribution - */ | 
| 141 |  |  | /*                              Preliminary Configuration and Validation," Solar */ | 
| 142 |  |  | /*                              Energy 50(3):235-245, Table 1. */ | 
| 143 |  |  |  | 
| 144 |  |  | static const double PerezCoeff[8][20] = | 
| 145 |  |  | { | 
| 146 |  |  | /* Sky clearness (epsilon): 1.000 to 1.065 */ | 
| 147 |  |  | {   1.3525,  -0.2576,  -0.2690,  -1.4366,   -0.7670, | 
| 148 |  |  | 0.0007,   1.2734,  -0.1233,   2.8000,    0.6004, | 
| 149 |  |  | 1.2375,   1.0000,   1.8734,   0.6297,    0.9738, | 
| 150 |  |  | 0.2809,   0.0356,  -0.1246,  -0.5718,    0.9938 }, | 
| 151 |  |  | /* Sky clearness (epsilon): 1.065 to 1.230 */ | 
| 152 |  |  | {  -1.2219,  -0.7730,   1.4148,   1.1016,   -0.2054, | 
| 153 |  |  | 0.0367,  -3.9128,   0.9156,   6.9750,    0.1774, | 
| 154 |  |  | 6.4477,  -0.1239,  -1.5798,  -0.5081,   -1.7812, | 
| 155 |  |  | 0.1080,   0.2624,   0.0672,  -0.2190,   -0.4285 }, | 
| 156 |  |  | /* Sky clearness (epsilon): 1.230 to 1.500 */ | 
| 157 |  |  | {  -1.1000,  -0.2515,   0.8952,   0.0156,    0.2782, | 
| 158 |  |  | -0.1812, - 4.5000,   1.1766,  24.7219,  -13.0812, | 
| 159 |  |  | -37.7000,  34.8438,  -5.0000,   1.5218,    3.9229, | 
| 160 |  |  | -2.6204,  -0.0156,   0.1597,   0.4199,   -0.5562 }, | 
| 161 |  |  | /* Sky clearness (epsilon): 1.500 to 1.950 */ | 
| 162 |  |  | {  -0.5484,  -0.6654,  -0.2672,   0.7117,   0.7234, | 
| 163 |  |  | -0.6219,  -5.6812,   2.6297,  33.3389, -18.3000, | 
| 164 |  |  | -62.2500,  52.0781,  -3.5000,   0.0016,   1.1477, | 
| 165 |  |  | 0.1062,   0.4659,  -0.3296,  -0.0876,  -0.0329 }, | 
| 166 |  |  | /* Sky clearness (epsilon): 1.950 to 2.800 */ | 
| 167 |  |  | {  -0.6000,  -0.3566,  -2.5000,   2.3250,   0.2937, | 
| 168 |  |  | 0.0496,  -5.6812,   1.8415,  21.0000,  -4.7656 , | 
| 169 |  |  | -21.5906,   7.2492,  -3.5000,  -0.1554,   1.4062, | 
| 170 |  |  | 0.3988,   0.0032,   0.0766,  -0.0656,  -0.1294 }, | 
| 171 |  |  | /* Sky clearness (epsilon): 2.800 to 4.500 */ | 
| 172 |  |  | {  -1.0156,  -0.3670,   1.0078,   1.4051,   0.2875, | 
| 173 |  |  | -0.5328,  -3.8500,   3.3750,  14.0000,  -0.9999, | 
| 174 |  |  | -7.1406,   7.5469,  -3.4000,  -0.1078,  -1.0750, | 
| 175 |  |  | 1.5702,  -0.0672,   0.4016,   0.3017,  -0.4844 }, | 
| 176 |  |  | /* Sky clearness (epsilon): 4.500 to 6.200 */ | 
| 177 |  |  | {  -1.0000,   0.0211,   0.5025,  -0.5119,  -0.3000, | 
| 178 |  |  | 0.1922,   0.7023,  -1.6317,  19.0000,  -5.0000, | 
| 179 |  |  | 1.2438,  -1.9094,  -4.0000,   0.0250,   0.3844, | 
| 180 |  |  | 0.2656,   1.0468,  -0.3788,  -2.4517,   1.4656 }, | 
| 181 |  |  | /* Sky clearness (epsilon): 6.200 to ... */ | 
| 182 |  |  | {  -1.0500,   0.0289,   0.4260,   0.3590,  -0.3250, | 
| 183 |  |  | 0.1156,   0.7781,   0.0025,  31.0625, -14.5000, | 
| 184 |  |  | -46.1148,  55.3750,  -7.2312,   0.4050,  13.3500, | 
| 185 |  |  | 0.6234,   1.5000,  -0.6426,   1.8564,   0.5636 } | 
| 186 |  |  | }; | 
| 187 |  |  |  | 
| 188 |  |  | /* Perez irradiance component model coefficients */ | 
| 189 |  |  |  | 
| 190 |  |  | /* Reference:   Perez, R., P. Ineichen, R. Seals, J. Michalsky, and R. */ | 
| 191 |  |  | /*                              Stewart. 1990. ìModeling Daylight Availability and */ | 
| 192 |  |  | /*                              Irradiance Components from Direct and Global */ | 
| 193 |  |  | /*                              Irradiance,î Solar Energy 44(5):271-289. */ | 
| 194 |  |  |  | 
| 195 |  |  | typedef struct | 
| 196 |  |  | { | 
| 197 |  |  | double lower;   /* Lower bound */ | 
| 198 |  |  | double upper;   /* Upper bound */ | 
| 199 |  |  | } CategoryBounds; | 
| 200 |  |  |  | 
| 201 |  |  | /* Perez sky clearness (epsilon) categories (Table 1) */ | 
| 202 |  |  | static const CategoryBounds SkyClearCat[8] = | 
| 203 |  |  | { | 
| 204 |  |  | { 1.000, 1.065 },       /* Overcast */ | 
| 205 |  |  | { 1.065, 1.230 }, | 
| 206 |  |  | { 1.230, 1.500 }, | 
| 207 |  |  | { 1.500, 1.950 }, | 
| 208 |  |  | { 1.950, 2.800 }, | 
| 209 |  |  | { 2.800, 4.500 }, | 
| 210 |  |  | { 4.500, 6.200 }, | 
| 211 |  |  | { 6.200, 12.00 }        /* Clear */ | 
| 212 |  |  | }; | 
| 213 |  |  |  | 
| 214 |  |  | /* Luminous efficacy model coefficients */ | 
| 215 |  |  | typedef struct | 
| 216 |  |  | { | 
| 217 |  |  | double a; | 
| 218 |  |  | double b; | 
| 219 |  |  | double c; | 
| 220 |  |  | double d; | 
| 221 |  |  | } ModelCoeff; | 
| 222 |  |  |  | 
| 223 |  |  | /* Diffuse luminous efficacy model coefficients (Table 4, Eqn. 7) */ | 
| 224 |  |  | static const ModelCoeff DiffuseLumEff[8] = | 
| 225 |  |  | { | 
| 226 |  |  | {  97.24, -0.46,  12.00,  -8.91 }, | 
| 227 |  |  | { 107.22,  1.15,   0.59,  -3.95 }, | 
| 228 |  |  | { 104.97,  2.96,  -5.53,  -8.77 }, | 
| 229 |  |  | { 102.39,  5.59, -13.95, -13.90 }, | 
| 230 |  |  | { 100.71,  5.94, -22.75, -23.74 }, | 
| 231 |  |  | { 106.42,  3.83, -36.15, -28.83 }, | 
| 232 |  |  | { 141.88,  1.90, -53.24, -14.03 }, | 
| 233 |  |  | { 152.23,  0.35, -45.27,  -7.98 } | 
| 234 |  |  | }; | 
| 235 |  |  |  | 
| 236 |  |  | /* Direct luminous efficacy model coefficients (Table 4, Eqn. 8) */ | 
| 237 |  |  | static const ModelCoeff DirectLumEff[8] = | 
| 238 |  |  | { | 
| 239 |  |  | {  57.20, -4.55, -2.98, 117.12 }, | 
| 240 |  |  | {  98.99, -3.46, -1.21,  12.38 }, | 
| 241 |  |  | { 109.83, -4.90, -1.71,  -8.81 }, | 
| 242 |  |  | { 110.34, -5.84, -1.99,  -4.56 }, | 
| 243 |  |  | { 106.36, -3.97, -1.75,  -6.16 }, | 
| 244 |  |  | { 107.19, -1.25, -1.51, -26.73 }, | 
| 245 |  |  | { 105.75,  0.77, -1.26, -34.44 }, | 
| 246 |  |  | { 101.18,  1.58, -1.10,  -8.29 } | 
| 247 |  |  | }; | 
| 248 |  |  |  | 
| 249 | greg | 2.3 | #ifndef NSUNPATCH | 
| 250 |  |  | #define NSUNPATCH       4               /* # patches to spread sun into */ | 
| 251 |  |  | #endif | 
| 252 |  |  |  | 
| 253 | greg | 2.1 | extern int jdate(int month, int day); | 
| 254 |  |  | extern double stadj(int  jd); | 
| 255 |  |  | extern double sdec(int  jd); | 
| 256 |  |  | extern double salt(double sd, double st); | 
| 257 |  |  | extern double sazi(double sd, double st); | 
| 258 |  |  | /* sun calculation constants */ | 
| 259 |  |  | extern double  s_latitude; | 
| 260 |  |  | extern double  s_longitude; | 
| 261 |  |  | extern double  s_meridian; | 
| 262 |  |  |  | 
| 263 |  |  | int             verbose = 0;            /* progress reports to stderr? */ | 
| 264 |  |  |  | 
| 265 |  |  | int             outfmt = 'a';           /* output format */ | 
| 266 |  |  |  | 
| 267 |  |  | int             rhsubdiv = 1;           /* Reinhart sky subdivisions */ | 
| 268 |  |  |  | 
| 269 | greg | 2.4 | COLOR           skycolor = {.96, 1.004, 1.118}; /* sky coloration */ | 
| 270 |  |  | COLOR           suncolor = {1., 1., 1.};        /* sun color */ | 
| 271 |  |  | COLOR           grefl = {.2, .2, .2};           /* ground reflectance */ | 
| 272 | greg | 2.1 |  | 
| 273 |  |  | int             nskypatch;              /* number of Reinhart patches */ | 
| 274 |  |  | float           *rh_palt;               /* sky patch altitudes (radians) */ | 
| 275 |  |  | float           *rh_pazi;               /* sky patch azimuths (radians) */ | 
| 276 |  |  | float           *rh_dom;                /* sky patch solid angle (sr) */ | 
| 277 |  |  |  | 
| 278 |  |  | #define         vector(v,alt,azi)       (       (v)[1] = tcos(alt), \ | 
| 279 |  |  | (v)[0] = (v)[1]*tsin(azi), \ | 
| 280 |  |  | (v)[1] *= tcos(azi), \ | 
| 281 |  |  | (v)[2] = tsin(alt) ) | 
| 282 |  |  |  | 
| 283 |  |  | #define         rh_vector(v,i)          vector(v,rh_palt[i],rh_pazi[i]) | 
| 284 |  |  |  | 
| 285 |  |  | #define         rh_cos(i)               tsin(rh_palt[i]) | 
| 286 |  |  |  | 
| 287 |  |  | extern int      rh_init(void); | 
| 288 |  |  | extern float *  resize_dmatrix(float *mtx_data, int nsteps, int npatch); | 
| 289 |  |  | extern void     AddDirect(float *parr); | 
| 290 |  |  |  | 
| 291 |  |  | int | 
| 292 |  |  | main(int argc, char *argv[]) | 
| 293 |  |  | { | 
| 294 |  |  | char    buf[256]; | 
| 295 |  |  | double  elevation;              /* site elevation (meters) */ | 
| 296 |  |  | int     dir_is_horiz;           /* direct is meas. on horizontal? */ | 
| 297 |  |  | float   *mtx_data = NULL;       /* our matrix data */ | 
| 298 |  |  | int     ntsteps = 0;            /* number of rows in matrix */ | 
| 299 |  |  | int     last_monthly = 0;       /* month of last report */ | 
| 300 |  |  | int     mo, da;                 /* month (1-12) and day (1-31) */ | 
| 301 |  |  | double  hr;                     /* hour (local standard time) */ | 
| 302 |  |  | double  dir, dif;               /* direct and diffuse values */ | 
| 303 |  |  | int     mtx_offset; | 
| 304 |  |  | int     i, j; | 
| 305 |  |  |  | 
| 306 |  |  | progname = argv[0]; | 
| 307 |  |  | /* get options */ | 
| 308 |  |  | for (i = 1; i < argc && argv[i][0] == '-'; i++) | 
| 309 |  |  | switch (argv[i][1]) { | 
| 310 | greg | 2.4 | case 'g':                       /* ground reflectance */ | 
| 311 |  |  | grefl[0] = atof(argv[++i]); | 
| 312 |  |  | grefl[1] = atof(argv[++i]); | 
| 313 |  |  | grefl[2] = atof(argv[++i]); | 
| 314 | greg | 2.1 | break; | 
| 315 | greg | 2.4 | case 'v':                       /* verbose progress reports */ | 
| 316 | greg | 2.1 | verbose++; | 
| 317 |  |  | break; | 
| 318 | greg | 2.4 | case 'o':                       /* output format */ | 
| 319 | greg | 2.1 | switch (argv[i][2]) { | 
| 320 |  |  | case 'f': | 
| 321 |  |  | case 'd': | 
| 322 |  |  | case 'a': | 
| 323 |  |  | outfmt = argv[i][2]; | 
| 324 |  |  | break; | 
| 325 |  |  | default: | 
| 326 |  |  | goto userr; | 
| 327 |  |  | } | 
| 328 |  |  | break; | 
| 329 | greg | 2.4 | case 'm':                       /* Reinhart subdivisions */ | 
| 330 | greg | 2.1 | rhsubdiv = atoi(argv[++i]); | 
| 331 |  |  | break; | 
| 332 | greg | 2.4 | case 'c':                       /* sky color */ | 
| 333 | greg | 2.1 | skycolor[0] = atof(argv[++i]); | 
| 334 |  |  | skycolor[1] = atof(argv[++i]); | 
| 335 |  |  | skycolor[2] = atof(argv[++i]); | 
| 336 |  |  | break; | 
| 337 | greg | 2.4 | case 'd':                       /* solar (direct) only */ | 
| 338 | greg | 2.1 | skycolor[0] = skycolor[1] = skycolor[2] = 0; | 
| 339 | greg | 2.4 | if (suncolor[1] <= 1e-4) | 
| 340 |  |  | suncolor[0] = suncolor[1] = suncolor[2] = 1; | 
| 341 | greg | 2.1 | break; | 
| 342 | greg | 2.4 | case 's':                       /* sky only (no direct) */ | 
| 343 |  |  | suncolor[0] = suncolor[1] = suncolor[2] = 0; | 
| 344 | greg | 2.1 | if (skycolor[1] <= 1e-4) | 
| 345 |  |  | skycolor[0] = skycolor[1] = skycolor[2] = 1; | 
| 346 |  |  | break; | 
| 347 |  |  | default: | 
| 348 |  |  | goto userr; | 
| 349 |  |  | } | 
| 350 |  |  | if (i < argc-1) | 
| 351 |  |  | goto userr; | 
| 352 |  |  | if (i == argc-1 && freopen(argv[i], "r", stdin) == NULL) { | 
| 353 |  |  | fprintf(stderr, "%s: cannot open '%s' for input\n", | 
| 354 |  |  | progname, argv[i]); | 
| 355 |  |  | exit(1); | 
| 356 |  |  | } | 
| 357 |  |  | if (verbose) { | 
| 358 |  |  | if (i == argc-1) | 
| 359 |  |  | fprintf(stderr, "%s: reading weather tape '%s'\n", | 
| 360 |  |  | progname, argv[i]); | 
| 361 |  |  | else | 
| 362 |  |  | fprintf(stderr, "%s: reading weather tape from <stdin>\n", | 
| 363 |  |  | progname); | 
| 364 |  |  | } | 
| 365 |  |  | /* read weather tape header */ | 
| 366 | greg | 2.2 | if (scanf("place %[^\r\n] ", buf) != 1) | 
| 367 | greg | 2.1 | goto fmterr; | 
| 368 |  |  | if (scanf("latitude %lf\n", &s_latitude) != 1) | 
| 369 |  |  | goto fmterr; | 
| 370 |  |  | if (scanf("longitude %lf\n", &s_longitude) != 1) | 
| 371 |  |  | goto fmterr; | 
| 372 |  |  | if (scanf("time_zone %lf\n", &s_meridian) != 1) | 
| 373 |  |  | goto fmterr; | 
| 374 |  |  | if (scanf("site_elevation %lf\n", &elevation) != 1) | 
| 375 |  |  | goto fmterr; | 
| 376 |  |  | if (scanf("weather_data_file_units %d\n", &input) != 1) | 
| 377 |  |  | goto fmterr; | 
| 378 |  |  | switch (input) {                /* translate units */ | 
| 379 |  |  | case 1: | 
| 380 |  |  | input = 1;              /* radiometric quantities */ | 
| 381 |  |  | dir_is_horiz = 0;       /* direct is perpendicular meas. */ | 
| 382 |  |  | break; | 
| 383 |  |  | case 2: | 
| 384 |  |  | input = 1;              /* radiometric quantities */ | 
| 385 |  |  | dir_is_horiz = 1;       /* solar measured horizontally */ | 
| 386 |  |  | break; | 
| 387 |  |  | case 3: | 
| 388 |  |  | input = 2;              /* photometric quantities */ | 
| 389 |  |  | dir_is_horiz = 0;       /* direct is perpendicular meas. */ | 
| 390 |  |  | break; | 
| 391 |  |  | default: | 
| 392 |  |  | goto fmterr; | 
| 393 |  |  | } | 
| 394 |  |  | rh_init();                      /* initialize sky patches */ | 
| 395 |  |  | if (verbose) { | 
| 396 |  |  | fprintf(stderr, "%s: location '%s'\n", progname, buf); | 
| 397 |  |  | fprintf(stderr, "%s: (lat,long)=(%.1f,%.1f) degrees north, west\n", | 
| 398 |  |  | progname, s_latitude, s_longitude); | 
| 399 |  |  | fprintf(stderr, "%s: %d sky patches per time step\n", | 
| 400 |  |  | progname, nskypatch); | 
| 401 |  |  | } | 
| 402 | greg | 2.2 | /* convert quantities to radians */ | 
| 403 |  |  | s_latitude = DegToRad(s_latitude); | 
| 404 |  |  | s_longitude = DegToRad(s_longitude); | 
| 405 |  |  | s_meridian = DegToRad(s_meridian); | 
| 406 | greg | 2.1 | /* process each time step in tape */ | 
| 407 |  |  | while (scanf("%d %d %lf %lf %lf\n", &mo, &da, &hr, &dir, &dif) == 5) { | 
| 408 |  |  | double          sda, sta; | 
| 409 |  |  | /* make space for next time step */ | 
| 410 |  |  | mtx_offset = 3*nskypatch*ntsteps++; | 
| 411 |  |  | mtx_data = resize_dmatrix(mtx_data, ntsteps, nskypatch); | 
| 412 |  |  | if (dif <= 1e-4) { | 
| 413 |  |  | memset(mtx_data+mtx_offset, 0, sizeof(float)*3*nskypatch); | 
| 414 |  |  | continue; | 
| 415 |  |  | } | 
| 416 |  |  | if (verbose && mo != last_monthly) | 
| 417 |  |  | fprintf(stderr, "%s: stepping through month %d...\n", | 
| 418 |  |  | progname, last_monthly=mo); | 
| 419 |  |  | /* compute solar position */ | 
| 420 |  |  | julian_date = jdate(mo, da); | 
| 421 |  |  | sda = sdec(julian_date); | 
| 422 |  |  | sta = stadj(julian_date); | 
| 423 |  |  | altitude = salt(sda, hr+sta); | 
| 424 | greg | 2.2 | azimuth = sazi(sda, hr+sta) + PI; | 
| 425 | greg | 2.1 | /* convert measured values */ | 
| 426 |  |  | if (dir_is_horiz && altitude > 0.) | 
| 427 |  |  | dir /= sin(altitude); | 
| 428 |  |  | if (input == 1) { | 
| 429 |  |  | dir_irrad = dir; | 
| 430 |  |  | diff_irrad = dif; | 
| 431 |  |  | } else /* input == 2 */ { | 
| 432 |  |  | dir_illum = dir; | 
| 433 |  |  | diff_illum = dif; | 
| 434 |  |  | } | 
| 435 |  |  | /* compute sky patch values */ | 
| 436 |  |  | ComputeSky(mtx_data+mtx_offset); | 
| 437 | greg | 2.4 | AddDirect(mtx_data+mtx_offset); | 
| 438 | greg | 2.1 | } | 
| 439 |  |  | /* check for junk at end */ | 
| 440 |  |  | while ((i = fgetc(stdin)) != EOF) | 
| 441 |  |  | if (!isspace(i)) { | 
| 442 |  |  | fprintf(stderr, "%s: warning - unexpected data past EOT: ", | 
| 443 |  |  | progname); | 
| 444 |  |  | buf[0] = i; buf[1] = '\0'; | 
| 445 |  |  | fgets(buf+1, sizeof(buf)-1, stdin); | 
| 446 |  |  | fputs(buf, stderr); fputc('\n', stderr); | 
| 447 |  |  | break; | 
| 448 |  |  | } | 
| 449 |  |  | /* write out matrix */ | 
| 450 |  |  | #ifdef getc_unlocked | 
| 451 |  |  | flockfile(stdout); | 
| 452 |  |  | #endif | 
| 453 |  |  | if (verbose) | 
| 454 |  |  | fprintf(stderr, "%s: writing %smatrix with %d time steps...\n", | 
| 455 |  |  | progname, outfmt=='a' ? "" : "binary ", ntsteps); | 
| 456 |  |  | /* patches are rows (outer sort) */ | 
| 457 |  |  | for (i = 0; i < nskypatch; i++) { | 
| 458 |  |  | mtx_offset = 3*i; | 
| 459 |  |  | switch (outfmt) { | 
| 460 |  |  | case 'a': | 
| 461 |  |  | for (j = 0; j < ntsteps; j++) { | 
| 462 | greg | 2.3 | printf("%.3g %.3g %.3g\n", mtx_data[mtx_offset], | 
| 463 | greg | 2.1 | mtx_data[mtx_offset+1], | 
| 464 |  |  | mtx_data[mtx_offset+2]); | 
| 465 |  |  | mtx_offset += 3*nskypatch; | 
| 466 |  |  | } | 
| 467 | greg | 2.2 | if (ntsteps > 1) | 
| 468 |  |  | fputc('\n', stdout); | 
| 469 | greg | 2.1 | break; | 
| 470 |  |  | case 'f': | 
| 471 |  |  | for (j = 0; j < ntsteps; j++) { | 
| 472 |  |  | fwrite(mtx_data+mtx_offset, sizeof(float), 3, | 
| 473 |  |  | stdout); | 
| 474 |  |  | mtx_offset += 3*nskypatch; | 
| 475 |  |  | } | 
| 476 |  |  | break; | 
| 477 |  |  | case 'd': | 
| 478 |  |  | for (j = 0; j < ntsteps; j++) { | 
| 479 |  |  | double  ment[3]; | 
| 480 |  |  | ment[0] = mtx_data[mtx_offset]; | 
| 481 |  |  | ment[1] = mtx_data[mtx_offset+1]; | 
| 482 |  |  | ment[2] = mtx_data[mtx_offset+2]; | 
| 483 |  |  | fwrite(ment, sizeof(double), 3, stdout); | 
| 484 |  |  | mtx_offset += 3*nskypatch; | 
| 485 |  |  | } | 
| 486 |  |  | break; | 
| 487 |  |  | } | 
| 488 |  |  | if (ferror(stdout)) | 
| 489 |  |  | goto writerr; | 
| 490 |  |  | } | 
| 491 |  |  | if (fflush(stdout) == EOF) | 
| 492 |  |  | goto writerr; | 
| 493 |  |  | if (verbose) | 
| 494 |  |  | fprintf(stderr, "%s: done.\n", progname); | 
| 495 |  |  | exit(0); | 
| 496 |  |  | userr: | 
| 497 | greg | 2.5 | fprintf(stderr, "Usage: %s [-v][-d|-s][-m N][-g r g b][-c r g b][-o{f|d}] [tape.wea]\n", | 
| 498 | greg | 2.1 | progname); | 
| 499 |  |  | exit(1); | 
| 500 |  |  | fmterr: | 
| 501 |  |  | fprintf(stderr, "%s: input weather tape format error\n", progname); | 
| 502 |  |  | exit(1); | 
| 503 |  |  | writerr: | 
| 504 |  |  | fprintf(stderr, "%s: write error on output\n", progname); | 
| 505 |  |  | exit(1); | 
| 506 |  |  | } | 
| 507 |  |  |  | 
| 508 |  |  | /* Return maximum of two doubles */ | 
| 509 |  |  | double dmax( double a, double b ) | 
| 510 |  |  | { return (a > b) ? a : b; } | 
| 511 |  |  |  | 
| 512 |  |  | /* Compute sky patch radiance values (modified by GW) */ | 
| 513 |  |  | void | 
| 514 |  |  | ComputeSky(float *parr) | 
| 515 |  |  | { | 
| 516 |  |  | int index;                      /* Category index */ | 
| 517 |  |  | double norm_diff_illum;         /* Normalized diffuse illuimnance */ | 
| 518 |  |  | int i; | 
| 519 |  |  |  | 
| 520 |  |  | /* Calculate atmospheric precipitable water content */ | 
| 521 |  |  | apwc = CalcPrecipWater(dew_point); | 
| 522 |  |  |  | 
| 523 | greg | 2.6 | /* Calculate sun zenith angle (don't let it dip below horizon) */ | 
| 524 |  |  | /* Also limit minimum angle to keep circumsolar off zenith */ | 
| 525 |  |  | if (altitude <= 0.0) | 
| 526 |  |  | sun_zenith = DegToRad(90.0); | 
| 527 |  |  | else if (altitude >= DegToRad(87.0)) | 
| 528 |  |  | sun_zenith = DegToRad(3.0); | 
| 529 |  |  | else | 
| 530 |  |  | sun_zenith = DegToRad(90.0) - altitude; | 
| 531 | greg | 2.1 |  | 
| 532 |  |  | /* Compute the inputs for the calculation of the sky distribution */ | 
| 533 |  |  |  | 
| 534 |  |  | if (input == 0)                                 /* XXX never used */ | 
| 535 |  |  | { | 
| 536 |  |  | /* Calculate irradiance */ | 
| 537 |  |  | diff_irrad = CalcDiffuseIrradiance(); | 
| 538 |  |  | dir_irrad = CalcDirectIrradiance(); | 
| 539 |  |  |  | 
| 540 |  |  | /* Calculate illuminance */ | 
| 541 |  |  | index = GetCategoryIndex(); | 
| 542 |  |  | diff_illum = diff_irrad * CalcDiffuseIllumRatio(index); | 
| 543 |  |  | dir_illum = dir_irrad * CalcDirectIllumRatio(index); | 
| 544 |  |  | } | 
| 545 |  |  | else if (input == 1) | 
| 546 |  |  | { | 
| 547 |  |  | sky_brightness = CalcSkyBrightness(); | 
| 548 |  |  | sky_clearness =  CalcSkyClearness(); | 
| 549 |  |  |  | 
| 550 |  |  | /* Calculate illuminance */ | 
| 551 |  |  | index = GetCategoryIndex(); | 
| 552 |  |  | diff_illum = diff_irrad * CalcDiffuseIllumRatio(index); | 
| 553 |  |  | dir_illum = dir_irrad * CalcDirectIllumRatio(index); | 
| 554 |  |  | } | 
| 555 |  |  | else if (input == 2) | 
| 556 |  |  | { | 
| 557 |  |  | /* Calculate sky brightness and clearness from illuminance values */ | 
| 558 |  |  | index = CalcSkyParamFromIllum(); | 
| 559 |  |  | } | 
| 560 |  |  |  | 
| 561 | greg | 2.2 | if (bright(skycolor) <= 1e-4) {                 /* 0 sky component? */ | 
| 562 |  |  | memset(parr, 0, sizeof(float)*3*nskypatch); | 
| 563 |  |  | return; | 
| 564 |  |  | } | 
| 565 | greg | 2.1 | /* Compute ground radiance (include solar contribution if any) */ | 
| 566 | greg | 2.3 | parr[0] = diff_illum; | 
| 567 | greg | 2.1 | if (altitude > 0) | 
| 568 | greg | 2.3 | parr[0] += dir_illum * sin(altitude); | 
| 569 | greg | 2.4 | parr[2] = parr[1] = parr[0] *= (1./PI/WHTEFFICACY); | 
| 570 |  |  | multcolor(parr, grefl); | 
| 571 | greg | 2.1 |  | 
| 572 |  |  | /* Calculate Perez sky model parameters */ | 
| 573 |  |  | CalcPerezParam(sun_zenith, sky_clearness, sky_brightness, index); | 
| 574 |  |  |  | 
| 575 |  |  | /* Calculate sky patch luminance values */ | 
| 576 |  |  | CalcSkyPatchLumin(parr); | 
| 577 |  |  |  | 
| 578 |  |  | /* Calculate relative horizontal illuminance */ | 
| 579 |  |  | norm_diff_illum = CalcRelHorzIllum(parr); | 
| 580 |  |  |  | 
| 581 |  |  | /* Normalization coefficient */ | 
| 582 |  |  | norm_diff_illum = diff_illum / norm_diff_illum; | 
| 583 |  |  |  | 
| 584 |  |  | /* Apply to sky patches to get absolute radiance values */ | 
| 585 |  |  | for (i = 1; i < nskypatch; i++) { | 
| 586 | greg | 2.7 | scalecolor(parr+3*i, norm_diff_illum*(1./WHTEFFICACY)); | 
| 587 | greg | 2.1 | multcolor(parr+3*i, skycolor); | 
| 588 |  |  | } | 
| 589 |  |  | } | 
| 590 |  |  |  | 
| 591 |  |  | /* Add in solar direct to nearest sky patches (GW) */ | 
| 592 |  |  | void | 
| 593 |  |  | AddDirect(float *parr) | 
| 594 |  |  | { | 
| 595 |  |  | FVECT   svec; | 
| 596 | greg | 2.3 | double  near_dprod[NSUNPATCH]; | 
| 597 |  |  | int     near_patch[NSUNPATCH]; | 
| 598 |  |  | double  wta[NSUNPATCH], wtot; | 
| 599 | greg | 2.1 | int     i, j, p; | 
| 600 |  |  |  | 
| 601 | greg | 2.4 | if (dir_illum <= 1e-4 || bright(suncolor) <= 1e-4) | 
| 602 | greg | 2.1 | return; | 
| 603 | greg | 2.3 | /* identify NSUNPATCH closest patches */ | 
| 604 |  |  | for (i = NSUNPATCH; i--; ) | 
| 605 | greg | 2.1 | near_dprod[i] = -1.; | 
| 606 |  |  | vector(svec, altitude, azimuth); | 
| 607 |  |  | for (p = 1; p < nskypatch; p++) { | 
| 608 |  |  | FVECT   pvec; | 
| 609 |  |  | double  dprod; | 
| 610 |  |  | rh_vector(pvec, p); | 
| 611 |  |  | dprod = DOT(pvec, svec); | 
| 612 | greg | 2.3 | for (i = 0; i < NSUNPATCH; i++) | 
| 613 | greg | 2.1 | if (dprod > near_dprod[i]) { | 
| 614 | greg | 2.3 | for (j = NSUNPATCH; --j > i; ) { | 
| 615 | greg | 2.1 | near_dprod[j] = near_dprod[j-1]; | 
| 616 |  |  | near_patch[j] = near_patch[j-1]; | 
| 617 |  |  | } | 
| 618 |  |  | near_dprod[i] = dprod; | 
| 619 |  |  | near_patch[i] = p; | 
| 620 |  |  | break; | 
| 621 |  |  | } | 
| 622 |  |  | } | 
| 623 |  |  | wtot = 0;                       /* weight by proximity */ | 
| 624 | greg | 2.3 | for (i = NSUNPATCH; i--; ) | 
| 625 | greg | 2.1 | wtot += wta[i] = 1./(1.002 - near_dprod[i]); | 
| 626 |  |  | /* add to nearest patch radiances */ | 
| 627 | greg | 2.3 | for (i = NSUNPATCH; i--; ) { | 
| 628 | greg | 2.2 | float   *pdest = parr + 3*near_patch[i]; | 
| 629 |  |  | float   val_add = wta[i] * dir_illum / | 
| 630 |  |  | (WHTEFFICACY * wtot * rh_dom[near_patch[i]]); | 
| 631 | greg | 2.4 | *pdest++ += val_add*suncolor[0]; | 
| 632 |  |  | *pdest++ += val_add*suncolor[1]; | 
| 633 |  |  | *pdest++ += val_add*suncolor[2]; | 
| 634 | greg | 2.2 | } | 
| 635 | greg | 2.1 | } | 
| 636 |  |  |  | 
| 637 |  |  | /* Initialize Reinhart sky patch positions (GW) */ | 
| 638 |  |  | int | 
| 639 |  |  | rh_init(void) | 
| 640 |  |  | { | 
| 641 |  |  | #define NROW    7 | 
| 642 |  |  | static const int        tnaz[NROW] = {30, 30, 24, 24, 18, 12, 6}; | 
| 643 |  |  | const double            alpha = (PI/2.)/(NROW*rhsubdiv + .5); | 
| 644 |  |  | int                     p, i, j; | 
| 645 |  |  | /* allocate patch angle arrays */ | 
| 646 |  |  | nskypatch = 0; | 
| 647 |  |  | for (p = 0; p < NROW; p++) | 
| 648 |  |  | nskypatch += tnaz[p]; | 
| 649 |  |  | nskypatch *= rhsubdiv*rhsubdiv; | 
| 650 |  |  | nskypatch += 2; | 
| 651 |  |  | rh_palt = (float *)malloc(sizeof(float)*nskypatch); | 
| 652 |  |  | rh_pazi = (float *)malloc(sizeof(float)*nskypatch); | 
| 653 |  |  | rh_dom = (float *)malloc(sizeof(float)*nskypatch); | 
| 654 |  |  | if ((rh_palt == NULL) | (rh_pazi == NULL) | (rh_dom == NULL)) { | 
| 655 |  |  | fprintf(stderr, "%s: out of memory in rh_init()\n", progname); | 
| 656 |  |  | exit(1); | 
| 657 |  |  | } | 
| 658 |  |  | rh_palt[0] = -PI/2.;            /* ground & zenith patches */ | 
| 659 |  |  | rh_pazi[0] = 0.; | 
| 660 |  |  | rh_dom[0] = 2.*PI; | 
| 661 |  |  | rh_palt[nskypatch-1] = PI/2.; | 
| 662 |  |  | rh_pazi[nskypatch-1] = 0.; | 
| 663 |  |  | rh_dom[nskypatch-1] = 2.*PI*(1. - cos(alpha*.5)); | 
| 664 |  |  | p = 1;                          /* "normal" patches */ | 
| 665 |  |  | for (i = 0; i < NROW*rhsubdiv; i++) { | 
| 666 |  |  | const float     ralt = alpha*(i + .5); | 
| 667 |  |  | const int       ninrow = tnaz[i/rhsubdiv]*rhsubdiv; | 
| 668 | greg | 2.3 | const float     dom = 2.*PI*(sin(alpha*(i+1)) - sin(alpha*i)) / | 
| 669 |  |  | (double)ninrow; | 
| 670 | greg | 2.1 | for (j = 0; j < ninrow; j++) { | 
| 671 |  |  | rh_palt[p] = ralt; | 
| 672 |  |  | rh_pazi[p] = 2.*PI * j / (double)ninrow; | 
| 673 |  |  | rh_dom[p++] = dom; | 
| 674 |  |  | } | 
| 675 |  |  | } | 
| 676 |  |  | return nskypatch; | 
| 677 |  |  | #undef NROW | 
| 678 |  |  | } | 
| 679 |  |  |  | 
| 680 |  |  | /* Resize daylight matrix (GW) */ | 
| 681 |  |  | float * | 
| 682 |  |  | resize_dmatrix(float *mtx_data, int nsteps, int npatch) | 
| 683 |  |  | { | 
| 684 |  |  | if (mtx_data == NULL) | 
| 685 |  |  | mtx_data = (float *)malloc(sizeof(float)*3*nsteps*npatch); | 
| 686 |  |  | else | 
| 687 |  |  | mtx_data = (float *)realloc(mtx_data, | 
| 688 |  |  | sizeof(float)*3*nsteps*npatch); | 
| 689 |  |  | if (mtx_data == NULL) { | 
| 690 |  |  | fprintf(stderr, "%s: out of memory in resize_dmatrix(%d,%d)\n", | 
| 691 |  |  | progname, nsteps, npatch); | 
| 692 |  |  | exit(1); | 
| 693 |  |  | } | 
| 694 |  |  | return(mtx_data); | 
| 695 |  |  | } | 
| 696 |  |  |  | 
| 697 |  |  | /* Determine category index */ | 
| 698 |  |  | int GetCategoryIndex() | 
| 699 |  |  | { | 
| 700 |  |  | int index;      /* Loop index */ | 
| 701 |  |  |  | 
| 702 |  |  | for (index = 0; index < 8; index++) | 
| 703 |  |  | if ((sky_clearness >= SkyClearCat[index].lower) && | 
| 704 |  |  | (sky_clearness < SkyClearCat[index].upper)) | 
| 705 |  |  | break; | 
| 706 |  |  |  | 
| 707 |  |  | return index; | 
| 708 |  |  | } | 
| 709 |  |  |  | 
| 710 |  |  | /* Calculate diffuse illuminance to diffuse irradiance ratio */ | 
| 711 |  |  |  | 
| 712 |  |  | /* Reference:   Perez, R., P. Ineichen, R. Seals, J. Michalsky, and R. */ | 
| 713 |  |  | /*                              Stewart. 1990. ìModeling Daylight Availability and */ | 
| 714 |  |  | /*                              Irradiance Components from Direct and Global */ | 
| 715 |  |  | /*                              Irradiance,î Solar Energy 44(5):271-289, Eqn. 7. */ | 
| 716 |  |  |  | 
| 717 |  |  | double CalcDiffuseIllumRatio( int index ) | 
| 718 |  |  | { | 
| 719 |  |  | ModelCoeff const *pnle; /* Category coefficient pointer */ | 
| 720 |  |  |  | 
| 721 |  |  | /* Get category coefficient pointer */ | 
| 722 |  |  | pnle = &(DiffuseLumEff[index]); | 
| 723 |  |  |  | 
| 724 |  |  | return pnle->a + pnle->b * apwc + pnle->c * cos(sun_zenith) + | 
| 725 |  |  | pnle->d * log(sky_brightness); | 
| 726 |  |  | } | 
| 727 |  |  |  | 
| 728 |  |  | /* Calculate direct illuminance to direct irradiance ratio */ | 
| 729 |  |  |  | 
| 730 |  |  | /* Reference:   Perez, R., P. Ineichen, R. Seals, J. Michalsky, and R. */ | 
| 731 |  |  | /*                              Stewart. 1990. ìModeling Daylight Availability and */ | 
| 732 |  |  | /*                              Irradiance Components from Direct and Global */ | 
| 733 |  |  | /*                              Irradiance,î Solar Energy 44(5):271-289, Eqn. 8. */ | 
| 734 |  |  |  | 
| 735 |  |  | double CalcDirectIllumRatio( int index ) | 
| 736 |  |  | { | 
| 737 |  |  | ModelCoeff const *pnle; /* Category coefficient pointer */ | 
| 738 |  |  |  | 
| 739 |  |  | /* Get category coefficient pointer */ | 
| 740 |  |  | pnle = &(DirectLumEff[index]); | 
| 741 |  |  |  | 
| 742 |  |  | /* Calculate direct illuminance from direct irradiance */ | 
| 743 |  |  |  | 
| 744 |  |  | return dmax((pnle->a + pnle->b * apwc + pnle->c * exp(5.73 * | 
| 745 |  |  | sun_zenith - 5.0) + pnle->d * sky_brightness), | 
| 746 |  |  | 0.0); | 
| 747 |  |  | } | 
| 748 |  |  |  | 
| 749 |  |  | /* Calculate sky brightness */ | 
| 750 |  |  |  | 
| 751 |  |  | /* Reference:   Perez, R., P. Ineichen, R. Seals, J. Michalsky, and R. */ | 
| 752 |  |  | /*                              Stewart. 1990. ìModeling Daylight Availability and */ | 
| 753 |  |  | /*                              Irradiance Components from Direct and Global */ | 
| 754 |  |  | /*                              Irradiance,î Solar Energy 44(5):271-289, Eqn. 2. */ | 
| 755 |  |  |  | 
| 756 |  |  | double CalcSkyBrightness() | 
| 757 |  |  | { | 
| 758 |  |  | return diff_irrad * CalcAirMass() / (DC_SolarConstantE * | 
| 759 |  |  | CalcEccentricity()); | 
| 760 |  |  | } | 
| 761 |  |  |  | 
| 762 |  |  | /* Calculate sky clearness */ | 
| 763 |  |  |  | 
| 764 |  |  | /* Reference:   Perez, R., P. Ineichen, R. Seals, J. Michalsky, and R. */ | 
| 765 |  |  | /*                              Stewart. 1990. ìModeling Daylight Availability and */ | 
| 766 |  |  | /*                              Irradiance Components from Direct and Global */ | 
| 767 |  |  | /*                              Irradiance,î Solar Energy 44(5):271-289, Eqn. 1. */ | 
| 768 |  |  |  | 
| 769 |  |  | double CalcSkyClearness() | 
| 770 |  |  | { | 
| 771 |  |  | double sz_cubed;        /* Sun zenith angle cubed */ | 
| 772 |  |  |  | 
| 773 |  |  | /* Calculate sun zenith angle cubed */ | 
| 774 |  |  | sz_cubed = pow(sun_zenith, 3.0); | 
| 775 |  |  |  | 
| 776 |  |  | return ((diff_irrad + dir_irrad) / diff_irrad + 1.041 * | 
| 777 |  |  | sz_cubed) / (1.0 + 1.041 * sz_cubed); | 
| 778 |  |  | } | 
| 779 |  |  |  | 
| 780 |  |  | /* Calculate diffuse horizontal irradiance from Perez sky brightness */ | 
| 781 |  |  |  | 
| 782 |  |  | /* Reference:   Perez, R., P. Ineichen, R. Seals, J. Michalsky, and R. */ | 
| 783 |  |  | /*                              Stewart. 1990. ìModeling Daylight Availability and */ | 
| 784 |  |  | /*                              Irradiance Components from Direct and Global */ | 
| 785 |  |  | /*                              Irradiance,î Solar Energy 44(5):271-289, Eqn. 2 */ | 
| 786 |  |  | /*                              (inverse). */ | 
| 787 |  |  |  | 
| 788 |  |  | double CalcDiffuseIrradiance() | 
| 789 |  |  | { | 
| 790 |  |  | return sky_brightness * DC_SolarConstantE * CalcEccentricity() / | 
| 791 |  |  | CalcAirMass(); | 
| 792 |  |  | } | 
| 793 |  |  |  | 
| 794 |  |  | /* Calculate direct normal irradiance from Perez sky clearness */ | 
| 795 |  |  |  | 
| 796 |  |  | /* Reference:   Perez, R., P. Ineichen, R. Seals, J. Michalsky, and R. */ | 
| 797 |  |  | /*                              Stewart. 1990. ìModeling Daylight Availability and */ | 
| 798 |  |  | /*                              Irradiance Components from Direct and Global */ | 
| 799 |  |  | /*                              Irradiance,î Solar Energy 44(5):271-289, Eqn. 1 */ | 
| 800 |  |  | /*                              (inverse). */ | 
| 801 |  |  |  | 
| 802 |  |  | double CalcDirectIrradiance() | 
| 803 |  |  | { | 
| 804 |  |  | return CalcDiffuseIrradiance() * ((sky_clearness - 1.0) * (1 + 1.041 | 
| 805 |  |  | * pow(sun_zenith, 3.0))); | 
| 806 |  |  | } | 
| 807 |  |  |  | 
| 808 |  |  | /* Calculate sky brightness and clearness from illuminance values */ | 
| 809 |  |  | int CalcSkyParamFromIllum() | 
| 810 |  |  | { | 
| 811 |  |  | double test1 = 0.1; | 
| 812 |  |  | double test2 = 0.1; | 
| 813 |  |  | int     counter = 0; | 
| 814 |  |  | int index = 0;                  /* Category index */ | 
| 815 |  |  |  | 
| 816 |  |  | /* Convert illuminance to irradiance */ | 
| 817 |  |  | diff_irrad = diff_illum * DC_SolarConstantE / | 
| 818 |  |  | (DC_SolarConstantL * 1000.0); | 
| 819 |  |  | dir_irrad = dir_illum * DC_SolarConstantE / | 
| 820 |  |  | (DC_SolarConstantL * 1000.0); | 
| 821 |  |  |  | 
| 822 |  |  | /* Calculate sky brightness and clearness */ | 
| 823 |  |  | sky_brightness = CalcSkyBrightness(); | 
| 824 |  |  | sky_clearness =  CalcSkyClearness(); | 
| 825 |  |  |  | 
| 826 |  |  | /* Limit sky clearness */ | 
| 827 |  |  | if (sky_clearness > 12.0) | 
| 828 |  |  | sky_clearness = 12.0; | 
| 829 |  |  |  | 
| 830 |  |  | /* Limit sky brightness */ | 
| 831 |  |  | if (sky_brightness < 0.05) | 
| 832 |  |  | sky_brightness = 0.01; | 
| 833 |  |  |  | 
| 834 |  |  | while (((fabs(diff_irrad - test1) > 10.0) || | 
| 835 |  |  | (fabs(dir_irrad - test2) > 10.0)) && !(counter == 5)) | 
| 836 |  |  | { | 
| 837 |  |  | test1 = diff_irrad; | 
| 838 |  |  | test2 = dir_irrad; | 
| 839 |  |  | counter++; | 
| 840 |  |  |  | 
| 841 |  |  | /* Convert illuminance to irradiance */ | 
| 842 |  |  | index = GetCategoryIndex(); | 
| 843 |  |  | diff_irrad = diff_illum / CalcDiffuseIllumRatio(index); | 
| 844 |  |  | dir_irrad = dir_illum / CalcDirectIllumRatio(index); | 
| 845 |  |  |  | 
| 846 |  |  | /* Calculate sky brightness and clearness */ | 
| 847 |  |  | sky_brightness = CalcSkyBrightness(); | 
| 848 |  |  | sky_clearness =  CalcSkyClearness(); | 
| 849 |  |  |  | 
| 850 |  |  | /* Limit sky clearness */ | 
| 851 |  |  | if (sky_clearness > 12.0) | 
| 852 |  |  | sky_clearness = 12.0; | 
| 853 |  |  |  | 
| 854 |  |  | /* Limit sky brightness */ | 
| 855 |  |  | if (sky_brightness < 0.05) | 
| 856 |  |  | sky_brightness = 0.01; | 
| 857 |  |  | } | 
| 858 |  |  |  | 
| 859 |  |  | return GetCategoryIndex(); | 
| 860 |  |  | } | 
| 861 |  |  |  | 
| 862 |  |  | /* Calculate relative luminance */ | 
| 863 |  |  |  | 
| 864 |  |  | /* Reference:   Perez, R., R. Seals, and J. Michalsky. 1993. */ | 
| 865 |  |  | /*                              ìAll-Weather Model for Sky Luminance Distribution - */ | 
| 866 |  |  | /*                              Preliminary Configuration and Validation,î Solar Energy */ | 
| 867 |  |  | /*                              50(3):235-245, Eqn. 1. */ | 
| 868 |  |  |  | 
| 869 |  |  | double CalcRelLuminance( double gamma, double zeta ) | 
| 870 |  |  | { | 
| 871 |  |  | return (1.0 + perez_param[0] * exp(perez_param[1] / cos(zeta))) * | 
| 872 |  |  | (1.0 + perez_param[2] * exp(perez_param[3] * gamma) + | 
| 873 |  |  | perez_param[4] * cos(gamma) * cos(gamma)); | 
| 874 |  |  | } | 
| 875 |  |  |  | 
| 876 |  |  | /* Calculate Perez sky model parameters */ | 
| 877 |  |  |  | 
| 878 |  |  | /* Reference:   Perez, R., R. Seals, and J. Michalsky. 1993. */ | 
| 879 |  |  | /*                              ìAll-Weather Model for Sky Luminance Distribution - */ | 
| 880 |  |  | /*                              Preliminary Configuration and Validation,î Solar Energy */ | 
| 881 |  |  | /*                              50(3):235-245, Eqns. 6 - 8. */ | 
| 882 |  |  |  | 
| 883 |  |  | void CalcPerezParam( double sz, double epsilon, double delta, | 
| 884 |  |  | int index ) | 
| 885 |  |  | { | 
| 886 |  |  | double x[5][4];         /* Coefficents a, b, c, d, e */ | 
| 887 |  |  | int i, j;                       /* Loop indices */ | 
| 888 |  |  |  | 
| 889 |  |  | /* Limit sky brightness */ | 
| 890 |  |  | if (epsilon > 1.065 && epsilon < 2.8) | 
| 891 |  |  | { | 
| 892 |  |  | if (delta < 0.2) | 
| 893 |  |  | delta = 0.2; | 
| 894 |  |  | } | 
| 895 |  |  |  | 
| 896 |  |  | /* Get Perez coefficients */ | 
| 897 |  |  | for (i = 0; i < 5; i++) | 
| 898 |  |  | for (j = 0; j < 4; j++) | 
| 899 |  |  | x[i][j] = PerezCoeff[index][4 * i + j]; | 
| 900 |  |  |  | 
| 901 |  |  | if (index != 0) | 
| 902 |  |  | { | 
| 903 |  |  | /* Calculate parameter a, b, c, d and e (Eqn. 6) */ | 
| 904 |  |  | for (i = 0; i < 5; i++) | 
| 905 |  |  | perez_param[i] = x[i][0] + x[i][1] * sz + delta * (x[i][2] + | 
| 906 |  |  | x[i][3] * sz); | 
| 907 |  |  | } | 
| 908 |  |  | else | 
| 909 |  |  | { | 
| 910 |  |  | /* Parameters a, b and e (Eqn. 6) */ | 
| 911 |  |  | perez_param[0] = x[0][0] + x[0][1] * sz + delta * (x[0][2] + | 
| 912 |  |  | x[0][3] * sz); | 
| 913 |  |  | perez_param[1] = x[1][0] + x[1][1] * sz + delta * (x[1][2] + | 
| 914 |  |  | x[1][3] * sz); | 
| 915 |  |  | perez_param[4] = x[4][0] + x[4][1] * sz + delta * (x[4][2] + | 
| 916 |  |  | x[4][3] * sz); | 
| 917 |  |  |  | 
| 918 |  |  | /* Parameter c (Eqn. 7) */ | 
| 919 |  |  | perez_param[2] = exp(pow(delta * (x[2][0] + x[2][1] * sz), | 
| 920 |  |  | x[2][2])) - x[2][3]; | 
| 921 |  |  |  | 
| 922 |  |  | /* Parameter d (Eqn. 8) */ | 
| 923 |  |  | perez_param[3] = -exp(delta * (x[3][0] + x[3][1] * sz)) + | 
| 924 |  |  | x[3][2] + delta * x[3][3]; | 
| 925 |  |  | } | 
| 926 |  |  | } | 
| 927 |  |  |  | 
| 928 |  |  | /* Calculate relative horizontal illuminance (modified by GW) */ | 
| 929 |  |  |  | 
| 930 |  |  | /* Reference:   Perez, R., R. Seals, and J. Michalsky. 1993. */ | 
| 931 |  |  | /*                              ìAll-Weather Model for Sky Luminance Distribution - */ | 
| 932 |  |  | /*                              Preliminary Configuration and Validation,î Solar Energy */ | 
| 933 |  |  | /*                              50(3):235-245, Eqn. 3. */ | 
| 934 |  |  |  | 
| 935 |  |  | double CalcRelHorzIllum( float *parr ) | 
| 936 |  |  | { | 
| 937 |  |  | int i; | 
| 938 |  |  | double rh_illum = 0.0;  /* Relative horizontal illuminance */ | 
| 939 |  |  |  | 
| 940 |  |  | for (i = 1; i < nskypatch; i++) | 
| 941 | greg | 2.7 | rh_illum += parr[3*i+1] * rh_cos(i) * rh_dom[i]; | 
| 942 | greg | 2.1 |  | 
| 943 | greg | 2.7 | return rh_illum; | 
| 944 | greg | 2.1 | } | 
| 945 |  |  |  | 
| 946 |  |  | /* Calculate earth orbit eccentricity correction factor */ | 
| 947 |  |  |  | 
| 948 |  |  | /* Reference:   Sen, Z. 2008. Solar Energy Fundamental and Modeling  */ | 
| 949 |  |  | /*                              Techniques. Springer, p. 72. */ | 
| 950 |  |  |  | 
| 951 |  |  | double CalcEccentricity() | 
| 952 |  |  | { | 
| 953 |  |  | double day_angle;       /* Day angle (radians) */ | 
| 954 |  |  | double E0;                      /* Eccentricity */ | 
| 955 |  |  |  | 
| 956 |  |  | /* Calculate day angle */ | 
| 957 |  |  | day_angle  = (julian_date - 1.0) * (2.0 * PI / 365.0); | 
| 958 |  |  |  | 
| 959 |  |  | /* Calculate eccentricity */ | 
| 960 |  |  | E0 = 1.00011 + 0.034221 * cos(day_angle) + 0.00128 * sin(day_angle) | 
| 961 |  |  | + 0.000719 * cos(2.0 * day_angle) + 0.000077 * sin(2.0 * | 
| 962 |  |  | day_angle); | 
| 963 |  |  |  | 
| 964 |  |  | return E0; | 
| 965 |  |  | } | 
| 966 |  |  |  | 
| 967 |  |  | /* Calculate atmospheric precipitable water content */ | 
| 968 |  |  |  | 
| 969 |  |  | /* Reference:   Perez, R., P. Ineichen, R. Seals, J. Michalsky, and R. */ | 
| 970 |  |  | /*                              Stewart. 1990. ìModeling Daylight Availability and */ | 
| 971 |  |  | /*                              Irradiance Components from Direct and Global */ | 
| 972 |  |  | /*                              Irradiance,î Solar Energy 44(5):271-289, Eqn. 3. */ | 
| 973 |  |  |  | 
| 974 |  |  | /* Note:        The default surface dew point temperature is 11 deg. C */ | 
| 975 |  |  | /*                      (52 deg. F). Typical values are: */ | 
| 976 |  |  |  | 
| 977 |  |  | /*                      Celsius         Fahrenheit              Human Perception */ | 
| 978 |  |  | /*                      > 24            > 75                    Extremely uncomfortable */ | 
| 979 |  |  | /*                      21 - 24         70 - 74                 Very humid */ | 
| 980 |  |  | /*                      18 - 21         65 - 69                 Somewhat uncomfortable */ | 
| 981 |  |  | /*                      16 - 18         60 - 64                 OK for most people */ | 
| 982 |  |  | /*                      13 - 16         55 - 59                 Comfortable */ | 
| 983 |  |  | /*                      10 - 12         50 - 54                 Very comfortable */ | 
| 984 |  |  | /*                      < 10            < 49                    A bit dry for some */ | 
| 985 |  |  |  | 
| 986 |  |  | double CalcPrecipWater( double dpt ) | 
| 987 |  |  | { return exp(0.07 * dpt - 0.075); } | 
| 988 |  |  |  | 
| 989 |  |  | /* Calculate relative air mass */ | 
| 990 |  |  |  | 
| 991 |  |  | /* Reference:   Kasten, F. 1966. "A New Table and Approximation Formula */ | 
| 992 |  |  | /*                              for the Relative Optical Air Mass," Arch. Meteorol. */ | 
| 993 |  |  | /*                              Geophys. Bioklimataol. Ser. B14, pp. 206-233. */ | 
| 994 |  |  |  | 
| 995 |  |  | /* Note:                More sophisticated relative air mass models are */ | 
| 996 |  |  | /*                              available, but they differ significantly only for */ | 
| 997 |  |  | /*                              sun zenith angles greater than 80 degrees. */ | 
| 998 |  |  |  | 
| 999 |  |  | double CalcAirMass() | 
| 1000 |  |  | { | 
| 1001 |  |  | return (1.0 / (cos(sun_zenith) + 0.15 * pow(93.885 - | 
| 1002 |  |  | RadToDeg(sun_zenith), -1.253))); | 
| 1003 |  |  | } | 
| 1004 |  |  |  | 
| 1005 |  |  | /* Calculate Perez All-Weather sky patch luminances (modified by GW) */ | 
| 1006 |  |  |  | 
| 1007 |  |  | /* NOTE: The sky patches centers are determined in accordance with the */ | 
| 1008 |  |  | /*       BRE-IDMP sky luminance measurement procedures. (See for example */ | 
| 1009 |  |  | /*       Mardaljevic, J. 2001. "The BRE-IDMP Dataset: A New Benchmark */ | 
| 1010 |  |  | /*       for the Validation of Illuminance Prediction Techniques," */ | 
| 1011 |  |  | /*       Lighting Research & Technology 33(2):117-136.) */ | 
| 1012 |  |  |  | 
| 1013 |  |  | void CalcSkyPatchLumin( float *parr ) | 
| 1014 |  |  | { | 
| 1015 |  |  | int i; | 
| 1016 |  |  | double aas;                             /* Sun-sky point azimuthal angle */ | 
| 1017 |  |  | double sspa;                    /* Sun-sky point angle */ | 
| 1018 |  |  | double zsa;                             /* Zenithal sun angle */ | 
| 1019 |  |  |  | 
| 1020 |  |  | for (i = 1; i < nskypatch; i++) | 
| 1021 |  |  | { | 
| 1022 |  |  | /* Calculate sun-sky point azimuthal angle */ | 
| 1023 |  |  | aas = fabs(rh_pazi[i] - azimuth); | 
| 1024 |  |  |  | 
| 1025 |  |  | /* Calculate zenithal sun angle */ | 
| 1026 |  |  | zsa = PI * 0.5 - rh_palt[i]; | 
| 1027 |  |  |  | 
| 1028 |  |  | /* Calculate sun-sky point angle (Equation 8-20) */ | 
| 1029 |  |  | sspa = acos(cos(sun_zenith) * cos(zsa) + sin(sun_zenith) * | 
| 1030 |  |  | sin(zsa) * cos(aas)); | 
| 1031 |  |  |  | 
| 1032 |  |  | /* Calculate patch luminance */ | 
| 1033 |  |  | parr[3*i] = CalcRelLuminance(sspa, zsa); | 
| 1034 |  |  | if (parr[3*i] < 0) parr[3*i] = 0; | 
| 1035 |  |  | parr[3*i+2] = parr[3*i+1] = parr[3*i]; | 
| 1036 |  |  | } | 
| 1037 |  |  | } |