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root/radiance/ray/src/gen/gendaymtx.c
Revision: 2.16
Committed: Tue Jun 17 21:01:21 2014 UTC (9 years, 9 months ago) by greg
Content type: text/plain
Branch: MAIN
CVS Tags: rad4R2, rad4R2P1
Changes since 2.15: +3 -3 lines
Log Message:
Fixed operator precedence error

File Contents

# User Rev Content
1 greg 2.1 #ifndef lint
2 greg 2.16 static const char RCSid[] = "$Id: gendaymtx.c,v 2.15 2014/06/17 18:51:47 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 greg 2.14 #include "platform.h"
90 greg 2.1 #include "color.h"
91    
92     char *progname; /* Program name */
93     char errmsg[128]; /* Error message buffer */
94     const double DC_SolarConstantE = 1367.0; /* Solar constant W/m^2 */
95     const double DC_SolarConstantL = 127.5; /* Solar constant klux */
96    
97     double altitude; /* Solar altitude (radians) */
98     double azimuth; /* Solar azimuth (radians) */
99     double apwc; /* Atmospheric precipitable water content */
100     double dew_point = 11.0; /* Surface dew point temperature (deg. C) */
101     double diff_illum; /* Diffuse illuminance */
102     double diff_irrad; /* Diffuse irradiance */
103     double dir_illum; /* Direct illuminance */
104     double dir_irrad; /* Direct irradiance */
105     int julian_date; /* Julian date */
106     double perez_param[5]; /* Perez sky model parameters */
107     double sky_brightness; /* Sky brightness */
108     double sky_clearness; /* Sky clearness */
109     double solar_rad; /* Solar radiance */
110     double sun_zenith; /* Sun zenith angle (radians) */
111     int input = 0; /* Input type */
112 greg 2.11 int output = 0; /* Output type */
113 greg 2.1
114     extern double dmax( double, double );
115     extern double CalcAirMass();
116     extern double CalcDiffuseIllumRatio( int );
117     extern double CalcDiffuseIrradiance();
118     extern double CalcDirectIllumRatio( int );
119     extern double CalcDirectIrradiance();
120     extern double CalcEccentricity();
121     extern double CalcPrecipWater( double );
122     extern double CalcRelHorzIllum( float *parr );
123     extern double CalcRelLuminance( double, double );
124     extern double CalcSkyBrightness();
125     extern double CalcSkyClearness();
126     extern int CalcSkyParamFromIllum();
127     extern int GetCategoryIndex();
128     extern void CalcPerezParam( double, double, double, int );
129     extern void CalcSkyPatchLumin( float *parr );
130     extern void ComputeSky( float *parr );
131    
132     /* Degrees into radians */
133     #define DegToRad(deg) ((deg)*(PI/180.))
134    
135     /* Radiuans into degrees */
136     #define RadToDeg(rad) ((rad)*(180./PI))
137    
138    
139     /* Perez sky model coefficients */
140    
141     /* Reference: Perez, R., R. Seals, and J. Michalsky, 1993. "All- */
142     /* Weather Model for Sky Luminance Distribution - */
143     /* Preliminary Configuration and Validation," Solar */
144     /* Energy 50(3):235-245, Table 1. */
145    
146     static const double PerezCoeff[8][20] =
147     {
148     /* Sky clearness (epsilon): 1.000 to 1.065 */
149     { 1.3525, -0.2576, -0.2690, -1.4366, -0.7670,
150     0.0007, 1.2734, -0.1233, 2.8000, 0.6004,
151     1.2375, 1.0000, 1.8734, 0.6297, 0.9738,
152     0.2809, 0.0356, -0.1246, -0.5718, 0.9938 },
153     /* Sky clearness (epsilon): 1.065 to 1.230 */
154     { -1.2219, -0.7730, 1.4148, 1.1016, -0.2054,
155     0.0367, -3.9128, 0.9156, 6.9750, 0.1774,
156     6.4477, -0.1239, -1.5798, -0.5081, -1.7812,
157     0.1080, 0.2624, 0.0672, -0.2190, -0.4285 },
158     /* Sky clearness (epsilon): 1.230 to 1.500 */
159     { -1.1000, -0.2515, 0.8952, 0.0156, 0.2782,
160     -0.1812, - 4.5000, 1.1766, 24.7219, -13.0812,
161     -37.7000, 34.8438, -5.0000, 1.5218, 3.9229,
162     -2.6204, -0.0156, 0.1597, 0.4199, -0.5562 },
163     /* Sky clearness (epsilon): 1.500 to 1.950 */
164     { -0.5484, -0.6654, -0.2672, 0.7117, 0.7234,
165     -0.6219, -5.6812, 2.6297, 33.3389, -18.3000,
166     -62.2500, 52.0781, -3.5000, 0.0016, 1.1477,
167     0.1062, 0.4659, -0.3296, -0.0876, -0.0329 },
168     /* Sky clearness (epsilon): 1.950 to 2.800 */
169     { -0.6000, -0.3566, -2.5000, 2.3250, 0.2937,
170     0.0496, -5.6812, 1.8415, 21.0000, -4.7656 ,
171     -21.5906, 7.2492, -3.5000, -0.1554, 1.4062,
172     0.3988, 0.0032, 0.0766, -0.0656, -0.1294 },
173     /* Sky clearness (epsilon): 2.800 to 4.500 */
174     { -1.0156, -0.3670, 1.0078, 1.4051, 0.2875,
175     -0.5328, -3.8500, 3.3750, 14.0000, -0.9999,
176     -7.1406, 7.5469, -3.4000, -0.1078, -1.0750,
177     1.5702, -0.0672, 0.4016, 0.3017, -0.4844 },
178     /* Sky clearness (epsilon): 4.500 to 6.200 */
179     { -1.0000, 0.0211, 0.5025, -0.5119, -0.3000,
180     0.1922, 0.7023, -1.6317, 19.0000, -5.0000,
181     1.2438, -1.9094, -4.0000, 0.0250, 0.3844,
182     0.2656, 1.0468, -0.3788, -2.4517, 1.4656 },
183     /* Sky clearness (epsilon): 6.200 to ... */
184     { -1.0500, 0.0289, 0.4260, 0.3590, -0.3250,
185     0.1156, 0.7781, 0.0025, 31.0625, -14.5000,
186     -46.1148, 55.3750, -7.2312, 0.4050, 13.3500,
187     0.6234, 1.5000, -0.6426, 1.8564, 0.5636 }
188     };
189    
190     /* Perez irradiance component model coefficients */
191    
192     /* Reference: Perez, R., P. Ineichen, R. Seals, J. Michalsky, and R. */
193     /* Stewart. 1990. ìModeling Daylight Availability and */
194     /* Irradiance Components from Direct and Global */
195     /* Irradiance,î Solar Energy 44(5):271-289. */
196    
197     typedef struct
198     {
199     double lower; /* Lower bound */
200     double upper; /* Upper bound */
201     } CategoryBounds;
202    
203     /* Perez sky clearness (epsilon) categories (Table 1) */
204     static const CategoryBounds SkyClearCat[8] =
205     {
206     { 1.000, 1.065 }, /* Overcast */
207     { 1.065, 1.230 },
208     { 1.230, 1.500 },
209     { 1.500, 1.950 },
210     { 1.950, 2.800 },
211     { 2.800, 4.500 },
212     { 4.500, 6.200 },
213 greg 2.12 { 6.200, 12.01 } /* Clear */
214 greg 2.1 };
215    
216     /* Luminous efficacy model coefficients */
217     typedef struct
218     {
219     double a;
220     double b;
221     double c;
222     double d;
223     } ModelCoeff;
224    
225     /* Diffuse luminous efficacy model coefficients (Table 4, Eqn. 7) */
226     static const ModelCoeff DiffuseLumEff[8] =
227     {
228     { 97.24, -0.46, 12.00, -8.91 },
229     { 107.22, 1.15, 0.59, -3.95 },
230     { 104.97, 2.96, -5.53, -8.77 },
231     { 102.39, 5.59, -13.95, -13.90 },
232     { 100.71, 5.94, -22.75, -23.74 },
233     { 106.42, 3.83, -36.15, -28.83 },
234     { 141.88, 1.90, -53.24, -14.03 },
235     { 152.23, 0.35, -45.27, -7.98 }
236     };
237    
238     /* Direct luminous efficacy model coefficients (Table 4, Eqn. 8) */
239     static const ModelCoeff DirectLumEff[8] =
240     {
241     { 57.20, -4.55, -2.98, 117.12 },
242     { 98.99, -3.46, -1.21, 12.38 },
243     { 109.83, -4.90, -1.71, -8.81 },
244     { 110.34, -5.84, -1.99, -4.56 },
245     { 106.36, -3.97, -1.75, -6.16 },
246     { 107.19, -1.25, -1.51, -26.73 },
247     { 105.75, 0.77, -1.26, -34.44 },
248     { 101.18, 1.58, -1.10, -8.29 }
249     };
250    
251 greg 2.3 #ifndef NSUNPATCH
252 greg 2.10 #define NSUNPATCH 4 /* max. # patches to spread sun into */
253 greg 2.3 #endif
254    
255 greg 2.1 extern int jdate(int month, int day);
256     extern double stadj(int jd);
257     extern double sdec(int jd);
258     extern double salt(double sd, double st);
259     extern double sazi(double sd, double st);
260     /* sun calculation constants */
261     extern double s_latitude;
262     extern double s_longitude;
263     extern double s_meridian;
264    
265 greg 2.10 int nsuns = NSUNPATCH; /* number of sun patches to use */
266     double fixed_sun_sa = -1; /* fixed solid angle per sun? */
267    
268 greg 2.1 int verbose = 0; /* progress reports to stderr? */
269    
270     int outfmt = 'a'; /* output format */
271    
272     int rhsubdiv = 1; /* Reinhart sky subdivisions */
273    
274 greg 2.4 COLOR skycolor = {.96, 1.004, 1.118}; /* sky coloration */
275     COLOR suncolor = {1., 1., 1.}; /* sun color */
276     COLOR grefl = {.2, .2, .2}; /* ground reflectance */
277 greg 2.1
278     int nskypatch; /* number of Reinhart patches */
279     float *rh_palt; /* sky patch altitudes (radians) */
280     float *rh_pazi; /* sky patch azimuths (radians) */
281     float *rh_dom; /* sky patch solid angle (sr) */
282    
283     #define vector(v,alt,azi) ( (v)[1] = tcos(alt), \
284     (v)[0] = (v)[1]*tsin(azi), \
285     (v)[1] *= tcos(azi), \
286     (v)[2] = tsin(alt) )
287    
288     #define rh_vector(v,i) vector(v,rh_palt[i],rh_pazi[i])
289    
290     #define rh_cos(i) tsin(rh_palt[i])
291    
292     extern int rh_init(void);
293     extern float * resize_dmatrix(float *mtx_data, int nsteps, int npatch);
294     extern void AddDirect(float *parr);
295    
296 greg 2.14
297     static const char *
298     getfmtname(int fmt)
299     {
300     switch (fmt) {
301     case 'a':
302     return("ascii");
303     case 'f':
304     return("float");
305     case 'd':
306     return("double");
307     }
308     return("unknown");
309     }
310    
311    
312 greg 2.1 int
313     main(int argc, char *argv[])
314     {
315     char buf[256];
316 greg 2.14 int doheader = 1; /* output header? */
317 greg 2.8 double rotation = 0; /* site rotation (degrees) */
318 greg 2.1 double elevation; /* site elevation (meters) */
319     int dir_is_horiz; /* direct is meas. on horizontal? */
320     float *mtx_data = NULL; /* our matrix data */
321     int ntsteps = 0; /* number of rows in matrix */
322 greg 2.16 int step_alloc = 0;
323 greg 2.1 int last_monthly = 0; /* month of last report */
324     int mo, da; /* month (1-12) and day (1-31) */
325     double hr; /* hour (local standard time) */
326     double dir, dif; /* direct and diffuse values */
327     int mtx_offset;
328     int i, j;
329    
330     progname = argv[0];
331     /* get options */
332     for (i = 1; i < argc && argv[i][0] == '-'; i++)
333     switch (argv[i][1]) {
334 greg 2.4 case 'g': /* ground reflectance */
335     grefl[0] = atof(argv[++i]);
336     grefl[1] = atof(argv[++i]);
337     grefl[2] = atof(argv[++i]);
338 greg 2.1 break;
339 greg 2.4 case 'v': /* verbose progress reports */
340 greg 2.1 verbose++;
341     break;
342 greg 2.14 case 'h': /* turn off header */
343     doheader = 0;
344     break;
345 greg 2.4 case 'o': /* output format */
346 greg 2.1 switch (argv[i][2]) {
347     case 'f':
348     case 'd':
349     case 'a':
350     outfmt = argv[i][2];
351     break;
352     default:
353     goto userr;
354     }
355     break;
356 greg 2.11 case 'O': /* output type */
357     switch (argv[i][2]) {
358     case '0':
359     output = 0;
360     break;
361     case '1':
362     output = 1;
363     break;
364     default:
365     goto userr;
366     }
367     if (argv[i][3])
368     goto userr;
369     break;
370 greg 2.4 case 'm': /* Reinhart subdivisions */
371 greg 2.1 rhsubdiv = atoi(argv[++i]);
372     break;
373 greg 2.4 case 'c': /* sky color */
374 greg 2.1 skycolor[0] = atof(argv[++i]);
375     skycolor[1] = atof(argv[++i]);
376     skycolor[2] = atof(argv[++i]);
377     break;
378 greg 2.4 case 'd': /* solar (direct) only */
379 greg 2.1 skycolor[0] = skycolor[1] = skycolor[2] = 0;
380 greg 2.4 if (suncolor[1] <= 1e-4)
381     suncolor[0] = suncolor[1] = suncolor[2] = 1;
382 greg 2.1 break;
383 greg 2.4 case 's': /* sky only (no direct) */
384     suncolor[0] = suncolor[1] = suncolor[2] = 0;
385 greg 2.1 if (skycolor[1] <= 1e-4)
386     skycolor[0] = skycolor[1] = skycolor[2] = 1;
387     break;
388 greg 2.8 case 'r': /* rotate distribution */
389     if (argv[i][2] && argv[i][2] != 'z')
390     goto userr;
391     rotation = atof(argv[++i]);
392     break;
393 greg 2.10 case '5': /* 5-phase calculation */
394     nsuns = 1;
395     fixed_sun_sa = 6.797e-05;
396     break;
397 greg 2.1 default:
398     goto userr;
399     }
400     if (i < argc-1)
401     goto userr;
402     if (i == argc-1 && freopen(argv[i], "r", stdin) == NULL) {
403     fprintf(stderr, "%s: cannot open '%s' for input\n",
404     progname, argv[i]);
405     exit(1);
406     }
407     if (verbose) {
408     if (i == argc-1)
409     fprintf(stderr, "%s: reading weather tape '%s'\n",
410     progname, argv[i]);
411     else
412     fprintf(stderr, "%s: reading weather tape from <stdin>\n",
413     progname);
414     }
415     /* read weather tape header */
416 greg 2.2 if (scanf("place %[^\r\n] ", buf) != 1)
417 greg 2.1 goto fmterr;
418     if (scanf("latitude %lf\n", &s_latitude) != 1)
419     goto fmterr;
420     if (scanf("longitude %lf\n", &s_longitude) != 1)
421     goto fmterr;
422     if (scanf("time_zone %lf\n", &s_meridian) != 1)
423     goto fmterr;
424     if (scanf("site_elevation %lf\n", &elevation) != 1)
425     goto fmterr;
426     if (scanf("weather_data_file_units %d\n", &input) != 1)
427     goto fmterr;
428     switch (input) { /* translate units */
429     case 1:
430     input = 1; /* radiometric quantities */
431     dir_is_horiz = 0; /* direct is perpendicular meas. */
432     break;
433     case 2:
434     input = 1; /* radiometric quantities */
435     dir_is_horiz = 1; /* solar measured horizontally */
436     break;
437     case 3:
438     input = 2; /* photometric quantities */
439     dir_is_horiz = 0; /* direct is perpendicular meas. */
440     break;
441     default:
442     goto fmterr;
443     }
444     rh_init(); /* initialize sky patches */
445     if (verbose) {
446     fprintf(stderr, "%s: location '%s'\n", progname, buf);
447     fprintf(stderr, "%s: (lat,long)=(%.1f,%.1f) degrees north, west\n",
448     progname, s_latitude, s_longitude);
449     fprintf(stderr, "%s: %d sky patches per time step\n",
450     progname, nskypatch);
451 greg 2.8 if (rotation != 0)
452     fprintf(stderr, "%s: rotating output %.0f degrees\n",
453     progname, rotation);
454 greg 2.1 }
455 greg 2.2 /* convert quantities to radians */
456     s_latitude = DegToRad(s_latitude);
457     s_longitude = DegToRad(s_longitude);
458     s_meridian = DegToRad(s_meridian);
459 greg 2.1 /* process each time step in tape */
460     while (scanf("%d %d %lf %lf %lf\n", &mo, &da, &hr, &dir, &dif) == 5) {
461     double sda, sta;
462     /* make space for next time step */
463     mtx_offset = 3*nskypatch*ntsteps++;
464 greg 2.15 if (ntsteps > step_alloc) {
465 greg 2.16 step_alloc += (step_alloc>>1) + ntsteps + 7;
466 greg 2.15 mtx_data = resize_dmatrix(mtx_data, step_alloc, nskypatch);
467     }
468 greg 2.1 if (dif <= 1e-4) {
469     memset(mtx_data+mtx_offset, 0, sizeof(float)*3*nskypatch);
470     continue;
471     }
472     if (verbose && mo != last_monthly)
473     fprintf(stderr, "%s: stepping through month %d...\n",
474     progname, last_monthly=mo);
475     /* compute solar position */
476     julian_date = jdate(mo, da);
477     sda = sdec(julian_date);
478     sta = stadj(julian_date);
479     altitude = salt(sda, hr+sta);
480 greg 2.8 azimuth = sazi(sda, hr+sta) + PI - DegToRad(rotation);
481 greg 2.1 /* convert measured values */
482     if (dir_is_horiz && altitude > 0.)
483     dir /= sin(altitude);
484     if (input == 1) {
485     dir_irrad = dir;
486     diff_irrad = dif;
487     } else /* input == 2 */ {
488     dir_illum = dir;
489     diff_illum = dif;
490     }
491     /* compute sky patch values */
492     ComputeSky(mtx_data+mtx_offset);
493 greg 2.4 AddDirect(mtx_data+mtx_offset);
494 greg 2.1 }
495     /* check for junk at end */
496     while ((i = fgetc(stdin)) != EOF)
497     if (!isspace(i)) {
498     fprintf(stderr, "%s: warning - unexpected data past EOT: ",
499     progname);
500     buf[0] = i; buf[1] = '\0';
501     fgets(buf+1, sizeof(buf)-1, stdin);
502     fputs(buf, stderr); fputc('\n', stderr);
503     break;
504     }
505     /* write out matrix */
506 greg 2.14 if (outfmt != 'a')
507     SET_FILE_BINARY(stdout);
508 greg 2.1 #ifdef getc_unlocked
509     flockfile(stdout);
510     #endif
511     if (verbose)
512     fprintf(stderr, "%s: writing %smatrix with %d time steps...\n",
513     progname, outfmt=='a' ? "" : "binary ", ntsteps);
514 greg 2.14 if (doheader) {
515     newheader("RADIANCE", stdout);
516     printargs(argc, argv, stdout);
517     printf("LATLONG= %.8f %.8f\n", RadToDeg(s_latitude),
518     -RadToDeg(s_longitude));
519     printf("NROWS=%d\n", nskypatch);
520     printf("NCOLS=%d\n", ntsteps);
521     printf("NCOMP=3\n");
522     fputformat(getfmtname(outfmt), stdout);
523     putchar('\n');
524     }
525 greg 2.1 /* patches are rows (outer sort) */
526     for (i = 0; i < nskypatch; i++) {
527     mtx_offset = 3*i;
528     switch (outfmt) {
529     case 'a':
530     for (j = 0; j < ntsteps; j++) {
531 greg 2.3 printf("%.3g %.3g %.3g\n", mtx_data[mtx_offset],
532 greg 2.1 mtx_data[mtx_offset+1],
533     mtx_data[mtx_offset+2]);
534     mtx_offset += 3*nskypatch;
535     }
536 greg 2.2 if (ntsteps > 1)
537     fputc('\n', stdout);
538 greg 2.1 break;
539     case 'f':
540     for (j = 0; j < ntsteps; j++) {
541     fwrite(mtx_data+mtx_offset, sizeof(float), 3,
542     stdout);
543     mtx_offset += 3*nskypatch;
544     }
545     break;
546     case 'd':
547     for (j = 0; j < ntsteps; j++) {
548     double ment[3];
549     ment[0] = mtx_data[mtx_offset];
550     ment[1] = mtx_data[mtx_offset+1];
551     ment[2] = mtx_data[mtx_offset+2];
552     fwrite(ment, sizeof(double), 3, stdout);
553     mtx_offset += 3*nskypatch;
554     }
555     break;
556     }
557     if (ferror(stdout))
558     goto writerr;
559     }
560     if (fflush(stdout) == EOF)
561     goto writerr;
562     if (verbose)
563     fprintf(stderr, "%s: done.\n", progname);
564     exit(0);
565     userr:
566 greg 2.14 fprintf(stderr, "Usage: %s [-v][-h][-d|-s][-r deg][-m N][-g r g b][-c r g b][-o{f|d}][-O{0|1}] [tape.wea]\n",
567 greg 2.1 progname);
568     exit(1);
569     fmterr:
570     fprintf(stderr, "%s: input weather tape format error\n", progname);
571     exit(1);
572     writerr:
573     fprintf(stderr, "%s: write error on output\n", progname);
574     exit(1);
575     }
576    
577     /* Return maximum of two doubles */
578     double dmax( double a, double b )
579     { return (a > b) ? a : b; }
580    
581     /* Compute sky patch radiance values (modified by GW) */
582     void
583     ComputeSky(float *parr)
584     {
585     int index; /* Category index */
586     double norm_diff_illum; /* Normalized diffuse illuimnance */
587     int i;
588    
589     /* Calculate atmospheric precipitable water content */
590     apwc = CalcPrecipWater(dew_point);
591    
592 greg 2.6 /* Calculate sun zenith angle (don't let it dip below horizon) */
593     /* Also limit minimum angle to keep circumsolar off zenith */
594     if (altitude <= 0.0)
595     sun_zenith = DegToRad(90.0);
596     else if (altitude >= DegToRad(87.0))
597     sun_zenith = DegToRad(3.0);
598     else
599     sun_zenith = DegToRad(90.0) - altitude;
600 greg 2.1
601     /* Compute the inputs for the calculation of the sky distribution */
602    
603     if (input == 0) /* XXX never used */
604     {
605     /* Calculate irradiance */
606     diff_irrad = CalcDiffuseIrradiance();
607     dir_irrad = CalcDirectIrradiance();
608    
609     /* Calculate illuminance */
610     index = GetCategoryIndex();
611     diff_illum = diff_irrad * CalcDiffuseIllumRatio(index);
612     dir_illum = dir_irrad * CalcDirectIllumRatio(index);
613     }
614     else if (input == 1)
615     {
616     sky_brightness = CalcSkyBrightness();
617     sky_clearness = CalcSkyClearness();
618    
619 greg 2.9 /* Limit sky clearness */
620     if (sky_clearness > 11.9)
621     sky_clearness = 11.9;
622    
623     /* Limit sky brightness */
624     if (sky_brightness < 0.01)
625 greg 2.11 sky_brightness = 0.01;
626 greg 2.9
627 greg 2.1 /* Calculate illuminance */
628     index = GetCategoryIndex();
629     diff_illum = diff_irrad * CalcDiffuseIllumRatio(index);
630     dir_illum = dir_irrad * CalcDirectIllumRatio(index);
631     }
632     else if (input == 2)
633     {
634     /* Calculate sky brightness and clearness from illuminance values */
635     index = CalcSkyParamFromIllum();
636     }
637    
638 greg 2.11 if (output == 1) { /* hack for solar radiance */
639     diff_illum = diff_irrad * WHTEFFICACY;
640     dir_illum = dir_irrad * WHTEFFICACY;
641     }
642    
643 greg 2.2 if (bright(skycolor) <= 1e-4) { /* 0 sky component? */
644     memset(parr, 0, sizeof(float)*3*nskypatch);
645     return;
646     }
647 greg 2.1 /* Compute ground radiance (include solar contribution if any) */
648 greg 2.3 parr[0] = diff_illum;
649 greg 2.1 if (altitude > 0)
650 greg 2.3 parr[0] += dir_illum * sin(altitude);
651 greg 2.4 parr[2] = parr[1] = parr[0] *= (1./PI/WHTEFFICACY);
652     multcolor(parr, grefl);
653 greg 2.1
654     /* Calculate Perez sky model parameters */
655     CalcPerezParam(sun_zenith, sky_clearness, sky_brightness, index);
656    
657     /* Calculate sky patch luminance values */
658     CalcSkyPatchLumin(parr);
659    
660     /* Calculate relative horizontal illuminance */
661     norm_diff_illum = CalcRelHorzIllum(parr);
662    
663 greg 2.13 /* Check for zero sky -- make uniform in that case */
664     if (norm_diff_illum <= FTINY) {
665     for (i = 1; i < nskypatch; i++)
666     setcolor(parr+3*i, 1., 1., 1.);
667     norm_diff_illum = PI;
668     }
669 greg 2.1 /* Normalization coefficient */
670     norm_diff_illum = diff_illum / norm_diff_illum;
671    
672     /* Apply to sky patches to get absolute radiance values */
673     for (i = 1; i < nskypatch; i++) {
674 greg 2.7 scalecolor(parr+3*i, norm_diff_illum*(1./WHTEFFICACY));
675 greg 2.1 multcolor(parr+3*i, skycolor);
676     }
677     }
678    
679     /* Add in solar direct to nearest sky patches (GW) */
680     void
681     AddDirect(float *parr)
682     {
683     FVECT svec;
684 greg 2.3 double near_dprod[NSUNPATCH];
685     int near_patch[NSUNPATCH];
686     double wta[NSUNPATCH], wtot;
687 greg 2.1 int i, j, p;
688    
689 greg 2.4 if (dir_illum <= 1e-4 || bright(suncolor) <= 1e-4)
690 greg 2.1 return;
691 greg 2.10 /* identify nsuns closest patches */
692     if (nsuns > NSUNPATCH)
693     nsuns = NSUNPATCH;
694     else if (nsuns <= 0)
695     nsuns = 1;
696     for (i = nsuns; i--; )
697 greg 2.1 near_dprod[i] = -1.;
698     vector(svec, altitude, azimuth);
699     for (p = 1; p < nskypatch; p++) {
700     FVECT pvec;
701     double dprod;
702     rh_vector(pvec, p);
703     dprod = DOT(pvec, svec);
704 greg 2.10 for (i = 0; i < nsuns; i++)
705 greg 2.1 if (dprod > near_dprod[i]) {
706 greg 2.10 for (j = nsuns; --j > i; ) {
707 greg 2.1 near_dprod[j] = near_dprod[j-1];
708     near_patch[j] = near_patch[j-1];
709     }
710     near_dprod[i] = dprod;
711     near_patch[i] = p;
712     break;
713     }
714     }
715     wtot = 0; /* weight by proximity */
716 greg 2.10 for (i = nsuns; i--; )
717 greg 2.1 wtot += wta[i] = 1./(1.002 - near_dprod[i]);
718     /* add to nearest patch radiances */
719 greg 2.10 for (i = nsuns; i--; ) {
720 greg 2.2 float *pdest = parr + 3*near_patch[i];
721 greg 2.10 float val_add = wta[i] * dir_illum / (WHTEFFICACY * wtot);
722    
723     val_add /= (fixed_sun_sa > 0) ? fixed_sun_sa
724     : rh_dom[near_patch[i]] ;
725 greg 2.4 *pdest++ += val_add*suncolor[0];
726     *pdest++ += val_add*suncolor[1];
727     *pdest++ += val_add*suncolor[2];
728 greg 2.2 }
729 greg 2.1 }
730    
731     /* Initialize Reinhart sky patch positions (GW) */
732     int
733     rh_init(void)
734     {
735     #define NROW 7
736     static const int tnaz[NROW] = {30, 30, 24, 24, 18, 12, 6};
737     const double alpha = (PI/2.)/(NROW*rhsubdiv + .5);
738     int p, i, j;
739     /* allocate patch angle arrays */
740     nskypatch = 0;
741     for (p = 0; p < NROW; p++)
742     nskypatch += tnaz[p];
743     nskypatch *= rhsubdiv*rhsubdiv;
744     nskypatch += 2;
745     rh_palt = (float *)malloc(sizeof(float)*nskypatch);
746     rh_pazi = (float *)malloc(sizeof(float)*nskypatch);
747     rh_dom = (float *)malloc(sizeof(float)*nskypatch);
748     if ((rh_palt == NULL) | (rh_pazi == NULL) | (rh_dom == NULL)) {
749     fprintf(stderr, "%s: out of memory in rh_init()\n", progname);
750     exit(1);
751     }
752     rh_palt[0] = -PI/2.; /* ground & zenith patches */
753     rh_pazi[0] = 0.;
754     rh_dom[0] = 2.*PI;
755     rh_palt[nskypatch-1] = PI/2.;
756     rh_pazi[nskypatch-1] = 0.;
757     rh_dom[nskypatch-1] = 2.*PI*(1. - cos(alpha*.5));
758     p = 1; /* "normal" patches */
759     for (i = 0; i < NROW*rhsubdiv; i++) {
760     const float ralt = alpha*(i + .5);
761     const int ninrow = tnaz[i/rhsubdiv]*rhsubdiv;
762 greg 2.3 const float dom = 2.*PI*(sin(alpha*(i+1)) - sin(alpha*i)) /
763     (double)ninrow;
764 greg 2.1 for (j = 0; j < ninrow; j++) {
765     rh_palt[p] = ralt;
766     rh_pazi[p] = 2.*PI * j / (double)ninrow;
767     rh_dom[p++] = dom;
768     }
769     }
770     return nskypatch;
771     #undef NROW
772     }
773    
774     /* Resize daylight matrix (GW) */
775     float *
776     resize_dmatrix(float *mtx_data, int nsteps, int npatch)
777     {
778     if (mtx_data == NULL)
779     mtx_data = (float *)malloc(sizeof(float)*3*nsteps*npatch);
780     else
781     mtx_data = (float *)realloc(mtx_data,
782     sizeof(float)*3*nsteps*npatch);
783     if (mtx_data == NULL) {
784     fprintf(stderr, "%s: out of memory in resize_dmatrix(%d,%d)\n",
785     progname, nsteps, npatch);
786     exit(1);
787     }
788     return(mtx_data);
789     }
790    
791     /* Determine category index */
792     int GetCategoryIndex()
793     {
794     int index; /* Loop index */
795    
796     for (index = 0; index < 8; index++)
797     if ((sky_clearness >= SkyClearCat[index].lower) &&
798     (sky_clearness < SkyClearCat[index].upper))
799     break;
800    
801     return index;
802     }
803    
804     /* Calculate diffuse illuminance to diffuse irradiance ratio */
805    
806     /* Reference: Perez, R., P. Ineichen, R. Seals, J. Michalsky, and R. */
807     /* Stewart. 1990. ìModeling Daylight Availability and */
808     /* Irradiance Components from Direct and Global */
809     /* Irradiance,î Solar Energy 44(5):271-289, Eqn. 7. */
810    
811     double CalcDiffuseIllumRatio( int index )
812     {
813     ModelCoeff const *pnle; /* Category coefficient pointer */
814    
815     /* Get category coefficient pointer */
816     pnle = &(DiffuseLumEff[index]);
817    
818     return pnle->a + pnle->b * apwc + pnle->c * cos(sun_zenith) +
819     pnle->d * log(sky_brightness);
820     }
821    
822     /* Calculate direct illuminance to direct irradiance ratio */
823    
824     /* Reference: Perez, R., P. Ineichen, R. Seals, J. Michalsky, and R. */
825     /* Stewart. 1990. ìModeling Daylight Availability and */
826     /* Irradiance Components from Direct and Global */
827     /* Irradiance,î Solar Energy 44(5):271-289, Eqn. 8. */
828    
829     double CalcDirectIllumRatio( int index )
830     {
831     ModelCoeff const *pnle; /* Category coefficient pointer */
832    
833     /* Get category coefficient pointer */
834     pnle = &(DirectLumEff[index]);
835    
836     /* Calculate direct illuminance from direct irradiance */
837    
838     return dmax((pnle->a + pnle->b * apwc + pnle->c * exp(5.73 *
839     sun_zenith - 5.0) + pnle->d * sky_brightness),
840     0.0);
841     }
842    
843     /* Calculate sky brightness */
844    
845     /* Reference: Perez, R., P. Ineichen, R. Seals, J. Michalsky, and R. */
846     /* Stewart. 1990. ìModeling Daylight Availability and */
847     /* Irradiance Components from Direct and Global */
848     /* Irradiance,î Solar Energy 44(5):271-289, Eqn. 2. */
849    
850     double CalcSkyBrightness()
851     {
852     return diff_irrad * CalcAirMass() / (DC_SolarConstantE *
853     CalcEccentricity());
854     }
855    
856     /* Calculate sky clearness */
857    
858     /* Reference: Perez, R., P. Ineichen, R. Seals, J. Michalsky, and R. */
859     /* Stewart. 1990. ìModeling Daylight Availability and */
860     /* Irradiance Components from Direct and Global */
861     /* Irradiance,î Solar Energy 44(5):271-289, Eqn. 1. */
862    
863     double CalcSkyClearness()
864     {
865     double sz_cubed; /* Sun zenith angle cubed */
866    
867     /* Calculate sun zenith angle cubed */
868 greg 2.11 sz_cubed = sun_zenith*sun_zenith*sun_zenith;
869 greg 2.1
870     return ((diff_irrad + dir_irrad) / diff_irrad + 1.041 *
871     sz_cubed) / (1.0 + 1.041 * sz_cubed);
872     }
873    
874     /* Calculate diffuse horizontal irradiance from Perez sky brightness */
875    
876     /* Reference: Perez, R., P. Ineichen, R. Seals, J. Michalsky, and R. */
877     /* Stewart. 1990. ìModeling Daylight Availability and */
878     /* Irradiance Components from Direct and Global */
879     /* Irradiance,î Solar Energy 44(5):271-289, Eqn. 2 */
880     /* (inverse). */
881    
882     double CalcDiffuseIrradiance()
883     {
884     return sky_brightness * DC_SolarConstantE * CalcEccentricity() /
885     CalcAirMass();
886     }
887    
888     /* Calculate direct normal irradiance from Perez sky clearness */
889    
890     /* Reference: Perez, R., P. Ineichen, R. Seals, J. Michalsky, and R. */
891     /* Stewart. 1990. ìModeling Daylight Availability and */
892     /* Irradiance Components from Direct and Global */
893     /* Irradiance,î Solar Energy 44(5):271-289, Eqn. 1 */
894     /* (inverse). */
895    
896     double CalcDirectIrradiance()
897     {
898     return CalcDiffuseIrradiance() * ((sky_clearness - 1.0) * (1 + 1.041
899 greg 2.11 * sun_zenith*sun_zenith*sun_zenith));
900 greg 2.1 }
901    
902     /* Calculate sky brightness and clearness from illuminance values */
903     int CalcSkyParamFromIllum()
904     {
905     double test1 = 0.1;
906     double test2 = 0.1;
907     int counter = 0;
908     int index = 0; /* Category index */
909    
910     /* Convert illuminance to irradiance */
911     diff_irrad = diff_illum * DC_SolarConstantE /
912     (DC_SolarConstantL * 1000.0);
913     dir_irrad = dir_illum * DC_SolarConstantE /
914     (DC_SolarConstantL * 1000.0);
915    
916     /* Calculate sky brightness and clearness */
917     sky_brightness = CalcSkyBrightness();
918     sky_clearness = CalcSkyClearness();
919    
920     /* Limit sky clearness */
921     if (sky_clearness > 12.0)
922     sky_clearness = 12.0;
923    
924     /* Limit sky brightness */
925 greg 2.9 if (sky_brightness < 0.01)
926 greg 2.1 sky_brightness = 0.01;
927    
928     while (((fabs(diff_irrad - test1) > 10.0) ||
929     (fabs(dir_irrad - test2) > 10.0)) && !(counter == 5))
930     {
931     test1 = diff_irrad;
932     test2 = dir_irrad;
933     counter++;
934    
935     /* Convert illuminance to irradiance */
936     index = GetCategoryIndex();
937     diff_irrad = diff_illum / CalcDiffuseIllumRatio(index);
938     dir_irrad = dir_illum / CalcDirectIllumRatio(index);
939    
940     /* Calculate sky brightness and clearness */
941     sky_brightness = CalcSkyBrightness();
942     sky_clearness = CalcSkyClearness();
943    
944     /* Limit sky clearness */
945     if (sky_clearness > 12.0)
946     sky_clearness = 12.0;
947    
948     /* Limit sky brightness */
949 greg 2.9 if (sky_brightness < 0.01)
950 greg 2.1 sky_brightness = 0.01;
951     }
952    
953     return GetCategoryIndex();
954     }
955    
956     /* Calculate relative luminance */
957    
958     /* Reference: Perez, R., R. Seals, and J. Michalsky. 1993. */
959     /* ìAll-Weather Model for Sky Luminance Distribution - */
960     /* Preliminary Configuration and Validation,î Solar Energy */
961     /* 50(3):235-245, Eqn. 1. */
962    
963     double CalcRelLuminance( double gamma, double zeta )
964     {
965     return (1.0 + perez_param[0] * exp(perez_param[1] / cos(zeta))) *
966     (1.0 + perez_param[2] * exp(perez_param[3] * gamma) +
967     perez_param[4] * cos(gamma) * cos(gamma));
968     }
969    
970     /* Calculate Perez sky model parameters */
971    
972     /* Reference: Perez, R., R. Seals, and J. Michalsky. 1993. */
973     /* ìAll-Weather Model for Sky Luminance Distribution - */
974     /* Preliminary Configuration and Validation,î Solar Energy */
975     /* 50(3):235-245, Eqns. 6 - 8. */
976    
977     void CalcPerezParam( double sz, double epsilon, double delta,
978     int index )
979     {
980     double x[5][4]; /* Coefficents a, b, c, d, e */
981     int i, j; /* Loop indices */
982    
983     /* Limit sky brightness */
984     if (epsilon > 1.065 && epsilon < 2.8)
985     {
986     if (delta < 0.2)
987     delta = 0.2;
988     }
989    
990     /* Get Perez coefficients */
991     for (i = 0; i < 5; i++)
992     for (j = 0; j < 4; j++)
993     x[i][j] = PerezCoeff[index][4 * i + j];
994    
995     if (index != 0)
996     {
997     /* Calculate parameter a, b, c, d and e (Eqn. 6) */
998     for (i = 0; i < 5; i++)
999     perez_param[i] = x[i][0] + x[i][1] * sz + delta * (x[i][2] +
1000     x[i][3] * sz);
1001     }
1002     else
1003     {
1004     /* Parameters a, b and e (Eqn. 6) */
1005     perez_param[0] = x[0][0] + x[0][1] * sz + delta * (x[0][2] +
1006     x[0][3] * sz);
1007     perez_param[1] = x[1][0] + x[1][1] * sz + delta * (x[1][2] +
1008     x[1][3] * sz);
1009     perez_param[4] = x[4][0] + x[4][1] * sz + delta * (x[4][2] +
1010     x[4][3] * sz);
1011    
1012     /* Parameter c (Eqn. 7) */
1013     perez_param[2] = exp(pow(delta * (x[2][0] + x[2][1] * sz),
1014     x[2][2])) - x[2][3];
1015    
1016     /* Parameter d (Eqn. 8) */
1017     perez_param[3] = -exp(delta * (x[3][0] + x[3][1] * sz)) +
1018     x[3][2] + delta * x[3][3];
1019     }
1020     }
1021    
1022     /* Calculate relative horizontal illuminance (modified by GW) */
1023    
1024     /* Reference: Perez, R., R. Seals, and J. Michalsky. 1993. */
1025     /* ìAll-Weather Model for Sky Luminance Distribution - */
1026     /* Preliminary Configuration and Validation,î Solar Energy */
1027     /* 50(3):235-245, Eqn. 3. */
1028    
1029     double CalcRelHorzIllum( float *parr )
1030     {
1031     int i;
1032     double rh_illum = 0.0; /* Relative horizontal illuminance */
1033    
1034     for (i = 1; i < nskypatch; i++)
1035 greg 2.7 rh_illum += parr[3*i+1] * rh_cos(i) * rh_dom[i];
1036 greg 2.1
1037 greg 2.7 return rh_illum;
1038 greg 2.1 }
1039    
1040     /* Calculate earth orbit eccentricity correction factor */
1041    
1042     /* Reference: Sen, Z. 2008. Solar Energy Fundamental and Modeling */
1043     /* Techniques. Springer, p. 72. */
1044    
1045     double CalcEccentricity()
1046     {
1047     double day_angle; /* Day angle (radians) */
1048     double E0; /* Eccentricity */
1049    
1050     /* Calculate day angle */
1051     day_angle = (julian_date - 1.0) * (2.0 * PI / 365.0);
1052    
1053     /* Calculate eccentricity */
1054     E0 = 1.00011 + 0.034221 * cos(day_angle) + 0.00128 * sin(day_angle)
1055     + 0.000719 * cos(2.0 * day_angle) + 0.000077 * sin(2.0 *
1056     day_angle);
1057    
1058     return E0;
1059     }
1060    
1061     /* Calculate atmospheric precipitable water content */
1062    
1063     /* Reference: Perez, R., P. Ineichen, R. Seals, J. Michalsky, and R. */
1064     /* Stewart. 1990. ìModeling Daylight Availability and */
1065     /* Irradiance Components from Direct and Global */
1066     /* Irradiance,î Solar Energy 44(5):271-289, Eqn. 3. */
1067    
1068     /* Note: The default surface dew point temperature is 11 deg. C */
1069     /* (52 deg. F). Typical values are: */
1070    
1071     /* Celsius Fahrenheit Human Perception */
1072     /* > 24 > 75 Extremely uncomfortable */
1073     /* 21 - 24 70 - 74 Very humid */
1074     /* 18 - 21 65 - 69 Somewhat uncomfortable */
1075     /* 16 - 18 60 - 64 OK for most people */
1076     /* 13 - 16 55 - 59 Comfortable */
1077     /* 10 - 12 50 - 54 Very comfortable */
1078     /* < 10 < 49 A bit dry for some */
1079    
1080     double CalcPrecipWater( double dpt )
1081     { return exp(0.07 * dpt - 0.075); }
1082    
1083     /* Calculate relative air mass */
1084    
1085     /* Reference: Kasten, F. 1966. "A New Table and Approximation Formula */
1086     /* for the Relative Optical Air Mass," Arch. Meteorol. */
1087     /* Geophys. Bioklimataol. Ser. B14, pp. 206-233. */
1088    
1089     /* Note: More sophisticated relative air mass models are */
1090     /* available, but they differ significantly only for */
1091     /* sun zenith angles greater than 80 degrees. */
1092    
1093     double CalcAirMass()
1094     {
1095     return (1.0 / (cos(sun_zenith) + 0.15 * pow(93.885 -
1096     RadToDeg(sun_zenith), -1.253)));
1097     }
1098    
1099     /* Calculate Perez All-Weather sky patch luminances (modified by GW) */
1100    
1101     /* NOTE: The sky patches centers are determined in accordance with the */
1102     /* BRE-IDMP sky luminance measurement procedures. (See for example */
1103     /* Mardaljevic, J. 2001. "The BRE-IDMP Dataset: A New Benchmark */
1104     /* for the Validation of Illuminance Prediction Techniques," */
1105     /* Lighting Research & Technology 33(2):117-136.) */
1106    
1107     void CalcSkyPatchLumin( float *parr )
1108     {
1109     int i;
1110     double aas; /* Sun-sky point azimuthal angle */
1111     double sspa; /* Sun-sky point angle */
1112     double zsa; /* Zenithal sun angle */
1113    
1114     for (i = 1; i < nskypatch; i++)
1115     {
1116     /* Calculate sun-sky point azimuthal angle */
1117     aas = fabs(rh_pazi[i] - azimuth);
1118    
1119     /* Calculate zenithal sun angle */
1120     zsa = PI * 0.5 - rh_palt[i];
1121    
1122     /* Calculate sun-sky point angle (Equation 8-20) */
1123     sspa = acos(cos(sun_zenith) * cos(zsa) + sin(sun_zenith) *
1124     sin(zsa) * cos(aas));
1125    
1126     /* Calculate patch luminance */
1127     parr[3*i] = CalcRelLuminance(sspa, zsa);
1128     if (parr[3*i] < 0) parr[3*i] = 0;
1129     parr[3*i+2] = parr[3*i+1] = parr[3*i];
1130     }
1131     }