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root/radiance/ray/src/gen/gendaylit.c
Revision: 2.16
Committed: Wed Jul 30 17:30:27 2014 UTC (9 years, 8 months ago) by greg
Content type: text/plain
Branch: MAIN
CVS Tags: rad4R2P2, rad5R0, rad5R1, rad4R2, rad4R2P1
Changes since 2.15: +1 -7 lines
Log Message:
Improved use of sun.h

File Contents

# Content
1 /* Copyright (c) 1994,2006 *Fraunhofer Institut for Solar Energy Systems
2 * Heidenhofstr. 2, D-79110 Freiburg, Germany
3 * *Agence de l'Environnement et de la Maitrise de l'Energie
4 * Centre de Valbonne, 500 route des Lucioles, 06565 Sophia Antipolis Cedex, France
5 * *BOUYGUES
6 * 1 Avenue Eugene Freyssinet, Saint-Quentin-Yvelines, France
7 */
8
9 #define _USE_MATH_DEFINES
10 #include <stdio.h>
11 #include <string.h>
12 #include <math.h>
13 #include <stdlib.h>
14
15 #include "color.h"
16 #include "sun.h"
17 #include "paths.h"
18
19 #define DOT(v1,v2) (v1[0]*v2[0]+v1[1]*v2[1]+v1[2]*v2[2])
20
21 double normsc();
22
23 /*static char *rcsid="$Header: /cvs/radiance/ray/src/gen/gendaylit.c,v 2.15 2013/11/18 18:07:16 greg Exp $";*/
24
25 float coeff_perez[] = {
26 1.3525,-0.2576,-0.2690,-1.4366,-0.7670,0.0007,1.2734,-0.1233,2.8000,0.6004,1.2375,1.000,1.8734,0.6297,
27 0.9738,0.2809,0.0356,-0.1246,-0.5718,0.9938,-1.2219,-0.7730,1.4148,1.1016,-0.2054,0.0367,-3.9128,0.9156,
28 6.9750,0.1774,6.4477,-0.1239,-1.5798,-0.5081,-1.7812,0.1080,0.2624,0.0672,-0.2190,-0.4285,-1.1000,-0.2515,
29 0.8952,0.0156,0.2782,-0.1812,-4.5000,1.1766,24.7219,-13.0812,-37.7000,34.8438,-5.0000,1.5218,3.9229,
30 -2.6204,-0.0156,0.1597,0.4199,-0.5562,-0.5484,-0.6654,-0.2672,0.7117,0.7234,-0.6219,-5.6812,2.6297,
31 33.3389,-18.3000,-62.2500,52.0781,-3.5000,0.0016,1.1477,0.1062,0.4659,-0.3296,-0.0876,-0.0329,-0.6000,
32 -0.3566,-2.5000,2.3250,0.2937,0.0496,-5.6812,1.8415,21.0000,-4.7656,-21.5906,7.2492,-3.5000,-0.1554,
33 1.4062,0.3988,0.0032,0.0766,-0.0656,-0.1294,-1.0156,-0.3670,1.0078,1.4051,0.2875,-0.5328,-3.8500,3.3750,
34 14.0000,-0.9999,-7.1406,7.5469,-3.4000,-0.1078,-1.0750,1.5702,-0.0672,0.4016,0.3017,-0.4844,-1.0000,
35 0.0211,0.5025,-0.5119,-0.3000,0.1922,0.7023,-1.6317,19.0000,-5.0000,1.2438,-1.9094,-4.0000,0.0250,0.3844,
36 0.2656,1.0468,-0.3788,-2.4517,1.4656,-1.0500,0.0289,0.4260,0.3590,-0.3250,0.1156,0.7781,0.0025,31.0625,
37 -14.5000,-46.1148,55.3750,-7.2312,0.4050,13.3500,0.6234,1.5000,-0.6426,1.8564,0.5636};
38
39
40 float defangle_theta[] = {
41 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84,
42 84, 84, 84, 84, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72,
43 72, 72, 72, 72, 72, 72, 72, 72, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60,
44 60, 60, 60, 60, 60, 60, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48,
45 48, 48, 48, 48, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 24, 24, 24, 24,
46 24, 24, 24, 24, 24, 24, 24, 24, 12, 12, 12, 12, 12, 12, 0};
47
48 float defangle_phi[] = {
49 0, 12, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, 240, 252, 264,
50 276, 288, 300, 312, 324, 336, 348, 0, 12, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180,
51 192, 204, 216, 228, 240, 252, 264, 276, 288, 300, 312, 324, 336, 348, 0, 15, 30, 45, 60, 75, 90, 105,
52 120, 135, 150, 165, 180, 195, 210, 225, 240, 255, 270, 285, 300, 315, 330, 345, 0, 15, 30, 45, 60, 75,
53 90, 105, 120, 135, 150, 165, 180, 195, 210, 225, 240, 255, 270, 285, 300, 315, 330, 345, 0, 20, 40, 60,
54 80, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280, 300, 320, 340, 0, 30, 60, 90, 120, 150, 180, 210,
55 240, 270, 300, 330, 0, 60, 120, 180, 240, 300, 0};
56
57
58
59 /* Perez sky parametrization: epsilon and delta calculations from the direct and diffuse irradiances */
60 double sky_brightness();
61 double sky_clearness();
62
63 /* calculation of the direct and diffuse components from the Perez parametrization */
64 double diffuse_irradiance_from_sky_brightness();
65 double direct_irradiance_from_sky_clearness();
66
67 /* Perez global horizontal, diffuse horizontal and direct normal luminous efficacy models : */
68 /* input w(cm)=2cm, solar zenith angle(degrees); output efficacy(lm/W) */
69
70 double glob_h_effi_PEREZ();
71 double glob_h_diffuse_effi_PEREZ();
72 double direct_n_effi_PEREZ();
73
74 /*likelihood check of the epsilon, delta, direct and diffuse components*/
75 void check_parametrization();
76 void check_irradiances();
77 void check_illuminances();
78 void illu_to_irra_index();
79 void print_error_sky();
80
81 double calc_rel_lum_perez(double dzeta,double gamma,double Z,double epsilon,double Delta,float coeff_perez[]);
82 void coeff_lum_perez(double Z, double epsilon, double Delta, float coeff_perez[]);
83 double radians(double degres);
84 double degres(double radians);
85 void theta_phi_to_dzeta_gamma(double theta,double phi,double *dzeta,double *gamma, double Z);
86 double integ_lv(float *lv,float *theta);
87
88 void printdefaults();
89 void check_sun_position();
90 void computesky();
91 void printhead(int ac, char** av);
92 void usage_error(char* msg);
93 void printsky();
94
95 FILE * frlibopen(char* fname);
96
97 /* astronomy and geometry*/
98 double get_eccentricity();
99 double air_mass();
100
101 double solar_sunset(int month, int day);
102 double solar_sunrise(int month, int day);
103 double stadj();
104 int jdate(int month, int day);
105
106 const double AU = 149597890E3;
107 const double solar_constant_e = 1367; /* solar constant W/m^2 */
108 const double solar_constant_l = 127500; /* solar constant lux */
109
110 const double half_sun_angle = 0.2665;
111 const double half_direct_angle = 2.85;
112
113 const double skyclearinf = 1.0; /* limitations for the variation of the Perez parameters */
114 const double skyclearsup = 12.01;
115 const double skybriginf = 0.01;
116 const double skybrigsup = 0.6;
117
118
119
120 /* required values */
121 int month, day; /* date */
122 double hour; /* time */
123 int tsolar; /* 0=standard, 1=solar */
124 double altitude, azimuth; /* or solar angles */
125
126
127
128 /* definition of the sky conditions through the Perez parametrization */
129 double skyclearness = 0;
130 double skybrightness = 0;
131 double solarradiance;
132 double diffuseilluminance, directilluminance, diffuseirradiance, directirradiance, globalirradiance;
133 double sunzenith, daynumber, atm_preci_water=2;
134
135 /*double sunaltitude_border = 0;*/
136 double diffnormalization = 0;
137 double dirnormalization = 0;
138 double *c_perez;
139
140 int output=0; /* define the unit of the output (sky luminance or radiance): */
141 /* visible watt=0, solar watt=1, lumen=2 */
142 int input=0; /* define the input for the calulation */
143
144 int suppress_warnings=0;
145
146 /* default values */
147 int cloudy = 0; /* 1=standard, 2=uniform */
148 int dosun = 1;
149 double zenithbr = -1.0;
150 double betaturbidity = 0.1;
151 double gprefl = 0.2;
152 int S_INTER=0;
153
154 /* computed values */
155 double sundir[3];
156 double groundbr = 0;
157 double F2;
158 double solarbr = 0.0;
159 int u_solar = 0; /* -1=irradiance, 1=radiance */
160 float timeinterval = 0;
161
162 char *progname;
163 char errmsg[128];
164
165 double st;
166
167
168 int main(int argc, char** argv)
169 {
170 int i;
171
172 progname = argv[0];
173 if (argc == 2 && !strcmp(argv[1], "-defaults")) {
174 printdefaults();
175 return 0;
176 }
177 if (argc < 4)
178 usage_error("arg count");
179 if (!strcmp(argv[1], "-ang")) {
180 altitude = atof(argv[2]) * (M_PI/180);
181 azimuth = atof(argv[3]) * (M_PI/180);
182 month = 0;
183 } else {
184 month = atoi(argv[1]);
185 if (month < 1 || month > 12)
186 usage_error("bad month");
187 day = atoi(argv[2]);
188 if (day < 1 || day > 31)
189 usage_error("bad day");
190 hour = atof(argv[3]);
191 if (hour < 0 || hour >= 24)
192 usage_error("bad hour");
193 tsolar = argv[3][0] == '+';
194 }
195 for (i = 4; i < argc; i++)
196 if (argv[i][0] == '-' || argv[i][0] == '+')
197 switch (argv[i][1]) {
198 case 's':
199 cloudy = 0;
200 dosun = argv[i][0] == '+';
201 break;
202 case 'R':
203 u_solar = argv[i][1] == 'R' ? -1 : 1;
204 solarbr = atof(argv[++i]);
205 break;
206 case 'c':
207 cloudy = argv[i][0] == '+' ? 2 : 1;
208 dosun = 0;
209 break;
210 case 't':
211 betaturbidity = atof(argv[++i]);
212 break;
213 case 'w':
214 suppress_warnings = 1;
215 break;
216 case 'b':
217 zenithbr = atof(argv[++i]);
218 break;
219 case 'g':
220 gprefl = atof(argv[++i]);
221 break;
222 case 'a':
223 s_latitude = atof(argv[++i]) * (M_PI/180);
224 break;
225 case 'o':
226 s_longitude = atof(argv[++i]) * (M_PI/180);
227 break;
228 case 'm':
229 s_meridian = atof(argv[++i]) * (M_PI/180);
230 break;
231
232 case 'O':
233 output = atof(argv[++i]); /*define the unit of the output of the program:
234 sky and sun luminance/radiance
235 (0==W visible, 1==W solar radiation, 2==lm) */
236 break;
237
238 case 'P':
239 input = 0; /* Perez parameters: epsilon, delta */
240 skyclearness = atof(argv[++i]);
241 skybrightness = atof(argv[++i]);
242 break;
243
244 case 'W': /* direct normal Irradiance [W/m^2] */
245 input = 1; /* diffuse horizontal Irrad. [W/m^2] */
246 directirradiance = atof(argv[++i]);
247 diffuseirradiance = atof(argv[++i]);
248 break;
249
250 case 'L': /* direct normal Illuminance [Lux] */
251 input = 2; /* diffuse horizontal Ill. [Lux] */
252 directilluminance = atof(argv[++i]);
253 diffuseilluminance = atof(argv[++i]);
254 break;
255
256 case 'G': /* direct horizontal Irradiance [W/m^2] */
257 input = 3; /* diffuse horizontal Irrad. [W/m^2] */
258 directirradiance = atof(argv[++i]);
259 diffuseirradiance = atof(argv[++i]);
260 break;
261
262 case 'E': /* Erbs model based on the */
263 input = 4; /* global-horizontal irradiance [W/m^2] */
264 globalirradiance = atof(argv[++i]);
265 break;
266
267 case 'i':
268 timeinterval = atof(argv[++i]);
269 break;
270
271
272 default:
273 sprintf(errmsg, "unknown option: %s", argv[i]);
274 usage_error(errmsg);
275 }
276 else
277 usage_error("bad option");
278
279 if (month && !tsolar && fabs(s_meridian-s_longitude) > 45*M_PI/180)
280 fprintf(stderr,"%s: warning: %.1f hours btwn. standard meridian and longitude\n",
281 progname, (s_longitude-s_meridian)*12/M_PI);
282
283
284 /* dynamic memory allocation for the pointers */
285 if ( (c_perez = calloc(5, sizeof(double))) == NULL )
286 { fprintf(stderr,"Out of memory error in function main"); return 1; }
287
288
289 printhead(argc, argv);
290 computesky();
291 printsky();
292 return 0;
293
294 }
295
296
297
298
299
300 void computesky()
301 {
302
303 int j;
304
305 float *lv_mod; /* 145 luminance values */
306 float *theta_o, *phi_o;
307 double dzeta, gamma;
308 double normfactor;
309 double erbs_s0, erbs_kt;
310
311
312 /* compute solar direction */
313
314 if (month) { /* from date and time */
315 int jd;
316 double sd;
317
318 jd = jdate(month, day); /* Julian date */
319 sd = sdec(jd); /* solar declination */
320 if (tsolar) /* solar time */
321 st = hour;
322 else
323 st = hour + stadj(jd);
324
325
326 if(timeinterval) {
327
328 if(timeinterval<0) {
329 fprintf(stderr, "time interval negative\n");
330 exit(1);
331 }
332
333 if(fabs(solar_sunrise(month,day)-st)<=timeinterval/120) {
334 st= (st+timeinterval/120+solar_sunrise(month,day))/2;
335 if(suppress_warnings==0)
336 { fprintf(stderr, "Solar position corrected at time step %d %d %.3f\n",month,day,hour); }
337 }
338
339 if(fabs(solar_sunset(month,day)-st)<timeinterval/120) {
340 st= (st-timeinterval/120+solar_sunset(month,day))/2;
341 if(suppress_warnings==0)
342 { fprintf(stderr, "Solar position corrected at time step %d %d %.3f\n",month,day,hour); }
343 }
344
345 if((st<solar_sunrise(month,day)-timeinterval/120) || (st>solar_sunset(month,day)+timeinterval/120)) {
346 if(suppress_warnings==0)
347 { fprintf(stderr, "Warning: sun position too low, printing error sky at %d %d %.3f\n",month,day,hour); }
348 altitude = salt(sd, st);
349 azimuth = sazi(sd, st);
350 print_error_sky();
351 exit(0);
352 }
353 }
354 else
355
356 if(st<solar_sunrise(month,day) || st>solar_sunset(month,day)) {
357 if(suppress_warnings==0)
358 { fprintf(stderr, "Warning: sun altitude below zero at time step %i %i %.2f, printing error sky\n",month,day,hour); }
359 altitude = salt(sd, st);
360 azimuth = sazi(sd, st);
361 print_error_sky();
362 exit(0);
363 }
364
365 altitude = salt(sd, st);
366 azimuth = sazi(sd, st);
367
368 daynumber = (double)jdate(month, day);
369
370 }
371
372
373
374
375
376 if (!cloudy && altitude > 87.*M_PI/180.) {
377
378 if (suppress_warnings==0) {
379 fprintf(stderr,
380 "%s: warning - sun too close to zenith, reducing altitude to 87 degrees\n",
381 progname);
382 }
383 altitude = 87.*M_PI/180.;
384 }
385
386
387
388 sundir[0] = -sin(azimuth)*cos(altitude);
389 sundir[1] = -cos(azimuth)*cos(altitude);
390 sundir[2] = sin(altitude);
391
392
393 /* calculation for the new functions */
394 sunzenith = 90 - altitude*180/M_PI;
395
396
397 /* compute the inputs for the calculation of the light distribution over the sky*/
398 if (input==0) /* P */
399 {
400 check_parametrization();
401 diffuseirradiance = diffuse_irradiance_from_sky_brightness(); /*diffuse horizontal irradiance*/
402 directirradiance = direct_irradiance_from_sky_clearness();
403 check_irradiances();
404
405 if (output==0 || output==2)
406 {
407 diffuseilluminance = diffuseirradiance*glob_h_diffuse_effi_PEREZ();/*diffuse horizontal illuminance*/
408 directilluminance = directirradiance*direct_n_effi_PEREZ();
409 check_illuminances();
410 }
411 }
412
413
414 else if (input==1) /* W */
415 {
416 check_irradiances();
417 skybrightness = sky_brightness();
418 skyclearness = sky_clearness();
419
420 check_parametrization();
421
422 if (output==0 || output==2)
423 {
424 diffuseilluminance = diffuseirradiance*glob_h_diffuse_effi_PEREZ();/*diffuse horizontal illuminance*/
425 directilluminance = directirradiance*direct_n_effi_PEREZ();
426 check_illuminances();
427 }
428
429 }
430
431
432 else if (input==2) /* L */
433 {
434 check_illuminances();
435 illu_to_irra_index();
436 check_parametrization();
437 }
438
439
440 else if (input==3) /* G */
441 {
442 if (altitude<=0)
443 {
444 if (suppress_warnings==0)
445 fprintf(stderr, "Warning: sun altitude < 0, proceed with irradiance values of zero\n");
446 directirradiance = 0;
447 diffuseirradiance = 0;
448 } else {
449
450 directirradiance=directirradiance/sin(altitude);
451 }
452
453 check_irradiances();
454 skybrightness = sky_brightness();
455 skyclearness = sky_clearness();
456 check_parametrization();
457
458 if (output==0 || output==2)
459 {
460 diffuseilluminance = diffuseirradiance*glob_h_diffuse_effi_PEREZ();/*diffuse horizontal illuminance*/
461 directilluminance = directirradiance*direct_n_effi_PEREZ();
462 check_illuminances();
463 }
464
465 }
466
467
468 else if (input==4) /* E */ /* Implementation of the Erbs model. W.Sprenger (04/13) */
469 {
470
471 if (altitude<=0)
472 {
473 if (suppress_warnings==0 && globalirradiance > 50)
474 fprintf(stderr, "Warning: global irradiance higher than 50 W/m^2 while the sun altitude is lower than zero\n");
475 globalirradiance = 0; diffuseirradiance = 0; directirradiance = 0;
476
477 } else {
478
479 erbs_s0 = solar_constant_e*get_eccentricity()*sin(altitude);
480
481 if (globalirradiance>erbs_s0)
482 {
483 if (suppress_warnings==0)
484 fprintf(stderr, "Warning: global irradiance is higher than the time-dependent solar constant s0\n");
485 globalirradiance=erbs_s0*0.999;
486 }
487
488 erbs_kt=globalirradiance/erbs_s0;
489
490 if (erbs_kt<=0.22) diffuseirradiance=globalirradiance*(1-0.09*erbs_kt);
491 else if (erbs_kt<=0.8) diffuseirradiance=globalirradiance*(0.9511-0.1604*erbs_kt+4.388*pow(erbs_kt,2)-16.638*pow(erbs_kt,3)+12.336*pow(erbs_kt,4));
492 else if (erbs_kt<1) diffuseirradiance=globalirradiance*(0.165);
493
494 directirradiance=globalirradiance-diffuseirradiance;
495
496 printf("# erbs_s0, erbs_kt, irr_dir_h, irr_diff: %.3f %.3f %.3f %.3f\n", erbs_s0, erbs_kt, directirradiance, diffuseirradiance);
497 printf("# WARNING: the -E option is only recommended for a rough estimation!\n");
498
499 directirradiance=directirradiance/sin(altitude);
500
501 }
502
503 check_irradiances();
504 skybrightness = sky_brightness();
505 skyclearness = sky_clearness();
506 check_parametrization();
507
508 if (output==0 || output==2)
509 {
510 diffuseilluminance = diffuseirradiance*glob_h_diffuse_effi_PEREZ();/*diffuse horizontal illuminance*/
511 directilluminance = directirradiance*direct_n_effi_PEREZ();
512 check_illuminances();
513 }
514
515 }
516
517
518
519
520 else { fprintf(stderr,"error at the input arguments"); exit(1); }
521
522
523
524 /* normalization factor for the relative sky luminance distribution, diffuse part*/
525
526 if ( (lv_mod = malloc(145*sizeof(float))) == NULL)
527 {
528 fprintf(stderr,"Out of memory in function main");
529 exit(1);
530 }
531
532 /* read the angles */
533 theta_o = defangle_theta;
534 phi_o = defangle_phi;
535
536
537 /* parameters for the perez model */
538 coeff_lum_perez(radians(sunzenith), skyclearness, skybrightness, coeff_perez);
539
540
541
542 /*calculation of the modelled luminance */
543 for (j=0;j<145;j++)
544 {
545 theta_phi_to_dzeta_gamma(radians(*(theta_o+j)),radians(*(phi_o+j)),&dzeta,&gamma,radians(sunzenith));
546
547 *(lv_mod+j) = calc_rel_lum_perez(dzeta,gamma,radians(sunzenith),skyclearness,skybrightness,coeff_perez);
548
549 /* fprintf(stderr,"theta, phi, lv_mod %f\t %f\t %f\n", *(theta_o+j),*(phi_o+j),*(lv_mod+j)); */
550 }
551
552 /* integration of luminance for the normalization factor, diffuse part of the sky*/
553
554 diffnormalization = integ_lv(lv_mod, theta_o);
555
556
557
558 /*normalization coefficient in lumen or in watt*/
559 if (output==0)
560 {
561 diffnormalization = diffuseilluminance/diffnormalization/WHTEFFICACY;
562 }
563 else if (output==1)
564 {
565 diffnormalization = diffuseirradiance/diffnormalization;
566 }
567 else if (output==2)
568 {
569 diffnormalization = diffuseilluminance/diffnormalization;
570 }
571
572 else {fprintf(stderr,"Wrong output specification.\n"); exit(1);}
573
574
575
576
577 /* calculation for the solar source */
578 if (output==0)
579 solarradiance = directilluminance/(2*M_PI*(1-cos(half_sun_angle*M_PI/180)))/WHTEFFICACY;
580
581 else if (output==1)
582 solarradiance = directirradiance/(2*M_PI*(1-cos(half_sun_angle*M_PI/180)));
583
584 else
585 solarradiance = directilluminance/(2*M_PI*(1-cos(half_sun_angle*M_PI/180)));
586
587
588
589 /* Compute the ground radiance */
590 zenithbr=calc_rel_lum_perez(0.0,radians(sunzenith),radians(sunzenith),skyclearness,skybrightness,coeff_perez);
591 zenithbr*=diffnormalization;
592
593 if (skyclearness==1)
594 normfactor = 0.777778;
595
596 if (skyclearness>=6)
597 {
598 F2 = 0.274*(0.91 + 10.0*exp(-3.0*(M_PI/2.0-altitude)) + 0.45*sundir[2]*sundir[2]);
599 normfactor = normsc()/F2/M_PI;
600 }
601
602 if ( (skyclearness>1) && (skyclearness<6) )
603 {
604 S_INTER=1;
605 F2 = (2.739 + .9891*sin(.3119+2.6*altitude)) * exp(-(M_PI/2.0-altitude)*(.4441+1.48*altitude));
606 normfactor = normsc()/F2/M_PI;
607 }
608
609 groundbr = zenithbr*normfactor;
610
611 if (dosun&&(skyclearness>1))
612 groundbr += 6.8e-5/M_PI*solarradiance*sundir[2];
613
614 groundbr *= gprefl;
615
616
617
618 if(*(c_perez+1)>0)
619 {
620 if(suppress_warnings==0)
621 { fprintf(stderr, "Warning: positive Perez parameter B (= %lf), printing error sky\n",*(c_perez+1));}
622 print_error_sky();
623 exit(0);
624 }
625
626
627 return;
628 }
629
630
631
632
633
634 double solar_sunset(int month,int day)
635 {
636 float W;
637 extern double s_latitude;
638 W=-1*(tan(s_latitude)*tan(sdec(jdate(month, day))));
639 return(12+(M_PI/2 - atan2(W,sqrt(1-W*W)))*180/(M_PI*15));
640 }
641
642
643
644
645 double solar_sunrise(int month,int day)
646 {
647 float W;
648 extern double s_latitude;
649 W=-1*(tan(s_latitude)*tan(sdec(jdate(month, day))));
650 return(12-(M_PI/2 - atan2(W,sqrt(1-W*W)))*180/(M_PI*15));
651 }
652
653
654
655
656 void printsky()
657 {
658
659 printf("# Local solar time: %.2f\n", st);
660 printf("# Solar altitude and azimuth: %.1f %.1f\n", altitude*180/M_PI, azimuth*180/M_PI);
661
662
663 if (dosun&&(skyclearness>1))
664 {
665 printf("\nvoid light solar\n");
666 printf("0\n0\n");
667 printf("3 %.3e %.3e %.3e\n", solarradiance, solarradiance, solarradiance);
668 printf("\nsolar source sun\n");
669 printf("0\n0\n");
670 printf("4 %f %f %f %f\n", sundir[0], sundir[1], sundir[2], 2*half_sun_angle);
671 } else if (dosun) {
672 printf("\nvoid light solar\n");
673 printf("0\n0\n");
674 printf("3 0.0 0.0 0.0\n");
675 printf("\nsolar source sun\n");
676 printf("0\n0\n");
677 printf("4 %f %f %f %f\n", sundir[0], sundir[1], sundir[2], 2*half_sun_angle);
678 }
679
680
681 printf("\nvoid brightfunc skyfunc\n");
682 printf("2 skybright perezlum.cal\n");
683 printf("0\n");
684 printf("10 %.3e %.3e %lf %lf %lf %lf %lf %f %f %f \n", diffnormalization, groundbr,
685 *(c_perez+0),*(c_perez+1),*(c_perez+2),*(c_perez+3),*(c_perez+4),
686 sundir[0], sundir[1], sundir[2]);
687
688 }
689
690
691
692 void print_error_sky()
693 {
694
695
696 sundir[0] = -sin(azimuth)*cos(altitude);
697 sundir[1] = -cos(azimuth)*cos(altitude);
698 sundir[2] = sin(altitude);
699
700 printf("# Local solar time: %.2f\n", st);
701 printf("# Solar altitude and azimuth: %.1f %.1f\n", altitude*180/M_PI, azimuth*180/M_PI);
702
703 printf("\nvoid brightfunc skyfunc\n");
704 printf("2 skybright perezlum.cal\n");
705 printf("0\n");
706 printf("10 0.00 0.00 0.000 0.000 0.000 0.000 0.000 %f %f %f \n", sundir[0], sundir[1], sundir[2]);
707 }
708
709
710
711
712
713 void printdefaults() /* print default values */
714 {
715 printf("-g %f\t\t\t# Ground plane reflectance\n", gprefl);
716 if (zenithbr > 0.0)
717 printf("-b %f\t\t\t# Zenith radiance (watts/ster/m^2\n", zenithbr);
718 else
719 printf("-t %f\t\t\t# Atmospheric betaturbidity\n", betaturbidity);
720 printf("-a %f\t\t\t# Site latitude (degrees)\n", s_latitude*(180/M_PI));
721 printf("-o %f\t\t\t# Site longitude (degrees)\n", s_longitude*(180/M_PI));
722 printf("-m %f\t\t\t# Standard meridian (degrees)\n", s_meridian*(180/M_PI));
723 }
724
725
726
727
728 void usage_error(char* msg) /* print usage error and quit */
729 {
730 if (msg != NULL)
731 fprintf(stderr, "%s: Use error - %s\n\n", progname, msg);
732 fprintf(stderr, "Usage: %s month day hour [...]\n", progname);
733 fprintf(stderr, " or: %s -ang altitude azimuth [...]\n", progname);
734 fprintf(stderr, " followed by: -P epsilon delta [options]\n");
735 fprintf(stderr, " or: [-W|-L|-G] direct_value diffuse_value [options]\n");
736 fprintf(stderr, " or: -E global_irradiance [options]\n\n");
737 fprintf(stderr, " Description:\n");
738 fprintf(stderr, " -P epsilon delta (these are the Perez parameters) \n");
739 fprintf(stderr, " -W direct-normal-irradiance diffuse-horizontal-irradiance (W/m^2)\n");
740 fprintf(stderr, " -L direct-normal-illuminance diffuse-horizontal-illuminance (lux)\n");
741 fprintf(stderr, " -G direct-horizontal-irradiance diffuse-horizontal-irradiance (W/m^2)\n");
742 fprintf(stderr, " -E global-horizontal-irradiance (W/m^2)\n\n");
743 fprintf(stderr, " Output specification with option:\n");
744 fprintf(stderr, " -O [0|1|2] (0=output in W/m^2/sr visible, 1=output in W/m^2/sr solar, 2=output in candela/m^2), default is 0 \n");
745 fprintf(stderr, " gendaylit version 2.4 (2013/09/04) \n\n");
746 exit(1);
747 }
748
749
750
751
752 double normsc() /* compute normalization factor (E0*F2/L0) */
753 {
754 static double nfc[2][5] = {
755 /* clear sky approx. */
756 {2.766521, 0.547665, -0.369832, 0.009237, 0.059229},
757 /* intermediate sky approx. */
758 {3.5556, -2.7152, -1.3081, 1.0660, 0.60227},
759 };
760 register double *nf;
761 double x, nsc;
762 register int i;
763 /* polynomial approximation */
764 nf = nfc[S_INTER];
765 x = (altitude - M_PI/4.0)/(M_PI/4.0);
766 nsc = nf[i=4];
767 while (i--)
768 nsc = nsc*x + nf[i];
769
770 return(nsc);
771 }
772
773
774
775
776
777 void printhead(int ac, char** av) /* print command header */
778 {
779 putchar('#');
780 while (ac--) {
781 putchar(' ');
782 fputs(*av++, stdout);
783 }
784 putchar('\n');
785 }
786
787
788
789
790
791
792 /* Perez models */
793
794 /* Perez global horizontal luminous efficacy model */
795 double glob_h_effi_PEREZ()
796 {
797
798 double value;
799 double category_bounds[10], a[10], b[10], c[10], d[10];
800 int category_total_number, category_number, i;
801
802 check_parametrization();
803
804
805 /*if ((skyclearness<skyclearinf || skyclearness>skyclearsup || skybrightness<skybriginf || skybrightness>skybrigsup) && suppress_warnings==0)
806 fprintf(stderr, "Warning: skyclearness or skybrightness out of range in function glob_h_effi_PEREZ \n"); */
807
808
809 /* initialize category bounds (clearness index bounds) */
810
811 category_total_number = 8;
812
813 category_bounds[1] = 1;
814 category_bounds[2] = 1.065;
815 category_bounds[3] = 1.230;
816 category_bounds[4] = 1.500;
817 category_bounds[5] = 1.950;
818 category_bounds[6] = 2.800;
819 category_bounds[7] = 4.500;
820 category_bounds[8] = 6.200;
821 category_bounds[9] = 12.01;
822
823
824 /* initialize model coefficients */
825 a[1] = 96.63;
826 a[2] = 107.54;
827 a[3] = 98.73;
828 a[4] = 92.72;
829 a[5] = 86.73;
830 a[6] = 88.34;
831 a[7] = 78.63;
832 a[8] = 99.65;
833
834 b[1] = -0.47;
835 b[2] = 0.79;
836 b[3] = 0.70;
837 b[4] = 0.56;
838 b[5] = 0.98;
839 b[6] = 1.39;
840 b[7] = 1.47;
841 b[8] = 1.86;
842
843 c[1] = 11.50;
844 c[2] = 1.79;
845 c[3] = 4.40;
846 c[4] = 8.36;
847 c[5] = 7.10;
848 c[6] = 6.06;
849 c[7] = 4.93;
850 c[8] = -4.46;
851
852 d[1] = -9.16;
853 d[2] = -1.19;
854 d[3] = -6.95;
855 d[4] = -8.31;
856 d[5] = -10.94;
857 d[6] = -7.60;
858 d[7] = -11.37;
859 d[8] = -3.15;
860
861
862
863 for (i=1; i<=category_total_number; i++)
864 {
865 if ( (skyclearness >= category_bounds[i]) && (skyclearness < category_bounds[i+1]) )
866 category_number = i;
867 }
868
869 value = a[category_number] + b[category_number]*atm_preci_water +
870 c[category_number]*cos(sunzenith*M_PI/180) + d[category_number]*log(skybrightness);
871
872 return(value);
873 }
874
875
876
877
878 /* global horizontal diffuse efficacy model, according to PEREZ */
879 double glob_h_diffuse_effi_PEREZ()
880 {
881 double value;
882 double category_bounds[10], a[10], b[10], c[10], d[10];
883 int category_total_number, category_number, i;
884
885 check_parametrization();
886
887
888 /*if ((skyclearness<skyclearinf || skyclearness>skyclearsup || skybrightness<skybriginf || skybrightness>skybrigsup) && suppress_warnings==0)
889 fprintf(stderr, "Warning: skyclearness or skybrightness out of range in function glob_h_diffuse_PEREZ \n"); */
890
891 /* initialize category bounds (clearness index bounds) */
892
893 category_total_number = 8;
894
895 //XXX: category_bounds > 0.1
896 category_bounds[1] = 1;
897 category_bounds[2] = 1.065;
898 category_bounds[3] = 1.230;
899 category_bounds[4] = 1.500;
900 category_bounds[5] = 1.950;
901 category_bounds[6] = 2.800;
902 category_bounds[7] = 4.500;
903 category_bounds[8] = 6.200;
904 category_bounds[9] = 12.01;
905
906
907 /* initialize model coefficients */
908 a[1] = 97.24;
909 a[2] = 107.22;
910 a[3] = 104.97;
911 a[4] = 102.39;
912 a[5] = 100.71;
913 a[6] = 106.42;
914 a[7] = 141.88;
915 a[8] = 152.23;
916
917 b[1] = -0.46;
918 b[2] = 1.15;
919 b[3] = 2.96;
920 b[4] = 5.59;
921 b[5] = 5.94;
922 b[6] = 3.83;
923 b[7] = 1.90;
924 b[8] = 0.35;
925
926 c[1] = 12.00;
927 c[2] = 0.59;
928 c[3] = -5.53;
929 c[4] = -13.95;
930 c[5] = -22.75;
931 c[6] = -36.15;
932 c[7] = -53.24;
933 c[8] = -45.27;
934
935 d[1] = -8.91;
936 d[2] = -3.95;
937 d[3] = -8.77;
938 d[4] = -13.90;
939 d[5] = -23.74;
940 d[6] = -28.83;
941 d[7] = -14.03;
942 d[8] = -7.98;
943
944
945
946 category_number = -1;
947 for (i=1; i<=category_total_number; i++)
948 {
949 if ( (skyclearness >= category_bounds[i]) && (skyclearness < category_bounds[i+1]) )
950 category_number = i;
951 }
952
953 if (category_number == -1) {
954 if (suppress_warnings==0)
955 fprintf(stderr, "Warning: sky clearness (= %.3f) too high, printing error sky\n", skyclearness);
956 print_error_sky();
957 exit(0);
958 }
959
960
961 value = a[category_number] + b[category_number]*atm_preci_water + c[category_number]*cos(sunzenith*M_PI/180) +
962 d[category_number]*log(skybrightness);
963
964 return(value);
965
966 }
967
968
969
970
971
972
973 /* direct normal efficacy model, according to PEREZ */
974
975 double direct_n_effi_PEREZ()
976
977 {
978 double value;
979 double category_bounds[10], a[10], b[10], c[10], d[10];
980 int category_total_number, category_number, i;
981
982
983 /*if ((skyclearness<skyclearinf || skyclearness>skyclearsup || skybrightness<skybriginf || skybrightness>skybrigsup) && suppress_warnings==0)
984 fprintf(stderr, "Warning: skyclearness or skybrightness out of range in function direct_n_effi_PEREZ \n");*/
985
986
987 /* initialize category bounds (clearness index bounds) */
988
989 category_total_number = 8;
990
991 category_bounds[1] = 1;
992 category_bounds[2] = 1.065;
993 category_bounds[3] = 1.230;
994 category_bounds[4] = 1.500;
995 category_bounds[5] = 1.950;
996 category_bounds[6] = 2.800;
997 category_bounds[7] = 4.500;
998 category_bounds[8] = 6.200;
999 category_bounds[9] = 12.1;
1000
1001
1002 /* initialize model coefficients */
1003 a[1] = 57.20;
1004 a[2] = 98.99;
1005 a[3] = 109.83;
1006 a[4] = 110.34;
1007 a[5] = 106.36;
1008 a[6] = 107.19;
1009 a[7] = 105.75;
1010 a[8] = 101.18;
1011
1012 b[1] = -4.55;
1013 b[2] = -3.46;
1014 b[3] = -4.90;
1015 b[4] = -5.84;
1016 b[5] = -3.97;
1017 b[6] = -1.25;
1018 b[7] = 0.77;
1019 b[8] = 1.58;
1020
1021 c[1] = -2.98;
1022 c[2] = -1.21;
1023 c[3] = -1.71;
1024 c[4] = -1.99;
1025 c[5] = -1.75;
1026 c[6] = -1.51;
1027 c[7] = -1.26;
1028 c[8] = -1.10;
1029
1030 d[1] = 117.12;
1031 d[2] = 12.38;
1032 d[3] = -8.81;
1033 d[4] = -4.56;
1034 d[5] = -6.16;
1035 d[6] = -26.73;
1036 d[7] = -34.44;
1037 d[8] = -8.29;
1038
1039
1040
1041 for (i=1; i<=category_total_number; i++)
1042 {
1043 if ( (skyclearness >= category_bounds[i]) && (skyclearness < category_bounds[i+1]) )
1044 category_number = i;
1045 }
1046
1047 value = a[category_number] + b[category_number]*atm_preci_water + c[category_number]*exp(5.73*sunzenith*M_PI/180 - 5) + d[category_number]*skybrightness;
1048
1049 if (value < 0) value = 0;
1050
1051 return(value);
1052 }
1053
1054
1055 /*check the range of epsilon and delta indexes of the perez parametrization*/
1056 void check_parametrization()
1057 {
1058
1059 if (skyclearness<skyclearinf || skyclearness>skyclearsup || skybrightness<skybriginf || skybrightness>skybrigsup)
1060 {
1061
1062 /* limit sky clearness or sky brightness, 2009 11 13 by J. Wienold */
1063
1064 if (skyclearness<skyclearinf){
1065 /* if (suppress_warnings==0)
1066 fprintf(stderr,"Range warning: sky clearness too low (%lf)\n", skyclearness); */
1067 skyclearness=skyclearinf;
1068 }
1069 if (skyclearness>skyclearsup){
1070 /* if (suppress_warnings==0)
1071 fprintf(stderr,"Range warning: sky clearness too high (%lf)\n", skyclearness); */
1072 skyclearness=skyclearsup-0.001;
1073 }
1074 if (skybrightness<skybriginf){
1075 /* if (suppress_warnings==0)
1076 fprintf(stderr,"Range warning: sky brightness too low (%lf)\n", skybrightness); */
1077 skybrightness=skybriginf;
1078 }
1079 if (skybrightness>skybrigsup){
1080 /* if (suppress_warnings==0)
1081 fprintf(stderr,"Range warning: sky brightness too high (%lf)\n", skybrightness); */
1082 skybrightness=skybrigsup;
1083 }
1084
1085 return; }
1086 else return;
1087 }
1088
1089
1090
1091
1092
1093 /* validity of the direct and diffuse components */
1094 void check_illuminances()
1095 {
1096 if (directilluminance < 0) {
1097 if(suppress_warnings==0)
1098 { fprintf(stderr,"Warning: direct illuminance < 0. Using 0.0\n"); }
1099 directilluminance = 0.0;
1100 }
1101 if (diffuseilluminance < 0) {
1102 if(suppress_warnings==0)
1103 { fprintf(stderr,"Warning: diffuse illuminance < 0. Using 0.0\n"); }
1104 diffuseilluminance = 0.0;
1105 }
1106
1107 if (directilluminance+diffuseilluminance==0 && altitude > 0) {
1108 if(suppress_warnings==0)
1109 { fprintf(stderr,"Warning: zero illuminance at sun altitude > 0, printing error sky\n"); }
1110 print_error_sky();
1111 exit(0);
1112 }
1113
1114 if (directilluminance > solar_constant_l) {
1115 if(suppress_warnings==0)
1116 { fprintf(stderr,"Warning: direct illuminance exceeds solar constant\n"); }
1117 print_error_sky();
1118 exit(0);
1119 }
1120 }
1121
1122
1123 void check_irradiances()
1124 {
1125 if (directirradiance < 0) {
1126 if(suppress_warnings==0)
1127 { fprintf(stderr,"Warning: direct irradiance < 0. Using 0.0\n"); }
1128 directirradiance = 0.0;
1129 }
1130 if (diffuseirradiance < 0) {
1131 if(suppress_warnings==0)
1132 { fprintf(stderr,"Warning: diffuse irradiance < 0. Using 0.0\n"); }
1133 diffuseirradiance = 0.0;
1134 }
1135
1136 if (directirradiance+diffuseirradiance==0 && altitude > 0) {
1137 if(suppress_warnings==0)
1138 { fprintf(stderr,"Warning: zero irradiance at sun altitude > 0, printing error sky\n"); }
1139 print_error_sky();
1140 exit(0);
1141 }
1142
1143 if (directirradiance > solar_constant_e) {
1144 if(suppress_warnings==0)
1145 { fprintf(stderr,"Warning: direct irradiance exceeds solar constant\n"); }
1146 print_error_sky();
1147 exit(0);
1148 }
1149 }
1150
1151
1152
1153 /* Perez sky's brightness */
1154 double sky_brightness()
1155 {
1156 double value;
1157
1158 value = diffuseirradiance * air_mass() / ( solar_constant_e*get_eccentricity());
1159
1160 return(value);
1161 }
1162
1163
1164 /* Perez sky's clearness */
1165 double sky_clearness()
1166 {
1167 double value;
1168
1169 value = ( (diffuseirradiance + directirradiance)/(diffuseirradiance) + 1.041*sunzenith*M_PI/180*sunzenith*M_PI/180*sunzenith*M_PI/180 ) / (1 + 1.041*sunzenith*M_PI/180*sunzenith*M_PI/180*sunzenith*M_PI/180) ;
1170
1171 return(value);
1172 }
1173
1174
1175
1176 /* diffus horizontal irradiance from Perez sky's brightness */
1177 double diffuse_irradiance_from_sky_brightness()
1178 {
1179 double value;
1180
1181 value = skybrightness / air_mass() * ( solar_constant_e*get_eccentricity());
1182
1183 return(value);
1184 }
1185
1186
1187 /* direct normal irradiance from Perez sky's clearness */
1188 double direct_irradiance_from_sky_clearness()
1189 {
1190 double value;
1191
1192 value = diffuse_irradiance_from_sky_brightness();
1193 value = value * ( (skyclearness-1) * (1+1.041*sunzenith*M_PI/180*sunzenith*M_PI/180*sunzenith*M_PI/180) );
1194
1195 return(value);
1196 }
1197
1198
1199
1200
1201 void illu_to_irra_index()
1202 {
1203 double test1=0.1, test2=0.1, d_eff;
1204 int counter=0;
1205
1206 diffuseirradiance = diffuseilluminance*solar_constant_e/(solar_constant_l);
1207 directirradiance = directilluminance*solar_constant_e/(solar_constant_l);
1208 skyclearness = sky_clearness();
1209 skybrightness = sky_brightness();
1210 check_parametrization();
1211
1212
1213 while ( ((fabs(diffuseirradiance-test1)>10) || (fabs(directirradiance-test2)>10)
1214 || (!(skyclearness<skyclearinf || skyclearness>skyclearsup))
1215 || (!(skybrightness<skybriginf || skybrightness>skybrigsup)) )
1216 && !(counter==9) )
1217 {
1218
1219 test1=diffuseirradiance;
1220 test2=directirradiance;
1221 counter++;
1222
1223 diffuseirradiance = diffuseilluminance/glob_h_diffuse_effi_PEREZ();
1224 d_eff = direct_n_effi_PEREZ();
1225
1226
1227 if (d_eff < 0.1)
1228 directirradiance = 0;
1229 else
1230 directirradiance = directilluminance/d_eff;
1231
1232 skybrightness = sky_brightness();
1233 skyclearness = sky_clearness();
1234 check_parametrization();
1235
1236 }
1237
1238
1239 return;
1240 }
1241
1242 static int get_numlin(float epsilon)
1243 {
1244 if (epsilon < 1.065)
1245 return 0;
1246 else if (epsilon < 1.230)
1247 return 1;
1248 else if (epsilon < 1.500)
1249 return 2;
1250 else if (epsilon < 1.950)
1251 return 3;
1252 else if (epsilon < 2.800)
1253 return 4;
1254 else if (epsilon < 4.500)
1255 return 5;
1256 else if (epsilon < 6.200)
1257 return 6;
1258 return 7;
1259 }
1260
1261 /* sky luminance perez model */
1262 double calc_rel_lum_perez(double dzeta,double gamma,double Z,double epsilon,double Delta,float coeff_perez[])
1263 {
1264
1265 float x[5][4];
1266 int i,j,num_lin;
1267 double c_perez[5];
1268
1269 if ( (epsilon < skyclearinf) || (epsilon >= skyclearsup) )
1270 {
1271 fprintf(stderr,"Error: epsilon out of range in function calc_rel_lum_perez!\n");
1272 exit(1);
1273 }
1274
1275 /* correction de modele de Perez solar energy ...*/
1276 if ( (epsilon > 1.065) && (epsilon < 2.8) )
1277 {
1278 if ( Delta < 0.2 ) Delta = 0.2;
1279 }
1280
1281
1282 num_lin = get_numlin(epsilon);
1283
1284 for (i=0;i<5;i++)
1285 for (j=0;j<4;j++)
1286 {
1287 x[i][j] = *(coeff_perez + 20*num_lin + 4*i +j);
1288 /* fprintf(stderr,"x %d %d vaut %f\n",i,j,x[i][j]); */
1289 }
1290
1291
1292 if (num_lin)
1293 {
1294 for (i=0;i<5;i++)
1295 c_perez[i] = x[i][0] + x[i][1]*Z + Delta * (x[i][2] + x[i][3]*Z);
1296 }
1297 else
1298 {
1299 c_perez[0] = x[0][0] + x[0][1]*Z + Delta * (x[0][2] + x[0][3]*Z);
1300 c_perez[1] = x[1][0] + x[1][1]*Z + Delta * (x[1][2] + x[1][3]*Z);
1301 c_perez[4] = x[4][0] + x[4][1]*Z + Delta * (x[4][2] + x[4][3]*Z);
1302 c_perez[2] = exp( pow(Delta*(x[2][0]+x[2][1]*Z),x[2][2])) - x[2][3];
1303 c_perez[3] = -exp( Delta*(x[3][0]+x[3][1]*Z) )+x[3][2]+Delta*x[3][3];
1304 }
1305
1306
1307 return (1 + c_perez[0]*exp(c_perez[1]/cos(dzeta)) ) *
1308 (1 + c_perez[2]*exp(c_perez[3]*gamma) +
1309 c_perez[4]*cos(gamma)*cos(gamma) );
1310 }
1311
1312
1313
1314 /* coefficients for the sky luminance perez model */
1315 void coeff_lum_perez(double Z, double epsilon, double Delta, float coeff_perez[])
1316 {
1317 float x[5][4];
1318 int i,j,num_lin;
1319
1320 if ( (epsilon < skyclearinf) || (epsilon >= skyclearsup) )
1321 {
1322 fprintf(stderr,"Error: epsilon out of range in function coeff_lum_perez!\n");
1323 exit(1);
1324 }
1325
1326 /* correction du modele de Perez solar energy ...*/
1327 if ( (epsilon > 1.065) && (epsilon < 2.8) )
1328 {
1329 if ( Delta < 0.2 ) Delta = 0.2;
1330 }
1331
1332
1333 num_lin = get_numlin(epsilon);
1334
1335 /*fprintf(stderr,"numlin %d\n", num_lin);*/
1336
1337 for (i=0;i<5;i++)
1338 for (j=0;j<4;j++)
1339 {
1340 x[i][j] = *(coeff_perez + 20*num_lin + 4*i +j);
1341 /* printf("x %d %d vaut %f\n",i,j,x[i][j]); */
1342 }
1343
1344
1345 if (num_lin)
1346 {
1347 for (i=0;i<5;i++)
1348 *(c_perez+i) = x[i][0] + x[i][1]*Z + Delta * (x[i][2] + x[i][3]*Z);
1349
1350 }
1351 else
1352 {
1353 *(c_perez+0) = x[0][0] + x[0][1]*Z + Delta * (x[0][2] + x[0][3]*Z);
1354 *(c_perez+1) = x[1][0] + x[1][1]*Z + Delta * (x[1][2] + x[1][3]*Z);
1355 *(c_perez+4) = x[4][0] + x[4][1]*Z + Delta * (x[4][2] + x[4][3]*Z);
1356 *(c_perez+2) = exp( pow(Delta*(x[2][0]+x[2][1]*Z),x[2][2])) - x[2][3];
1357 *(c_perez+3) = -exp( Delta*(x[3][0]+x[3][1]*Z) )+x[3][2]+Delta*x[3][3];
1358
1359
1360 }
1361
1362
1363 return;
1364 }
1365
1366
1367
1368 /* degrees into radians */
1369 double radians(double degres)
1370 {
1371 return degres*M_PI/180.0;
1372 }
1373
1374
1375 /* radian into degrees */
1376 double degres(double radians)
1377 {
1378 return radians/M_PI*180.0;
1379 }
1380
1381
1382 /* calculation of the angles dzeta and gamma */
1383 void theta_phi_to_dzeta_gamma(double theta,double phi,double *dzeta,double *gamma, double Z)
1384 {
1385 *dzeta = theta; /* dzeta = phi */
1386 if ( (cos(Z)*cos(theta)+sin(Z)*sin(theta)*cos(phi)) > 1 && (cos(Z)*cos(theta)+sin(Z)*sin(theta)*cos(phi) < 1.1 ) )
1387 *gamma = 0;
1388 else if ( (cos(Z)*cos(theta)+sin(Z)*sin(theta)*cos(phi)) > 1.1 )
1389 {
1390 printf("error in calculation of gamma (angle between point and sun");
1391 exit(1);
1392 }
1393 else
1394 *gamma = acos(cos(Z)*cos(theta)+sin(Z)*sin(theta)*cos(phi));
1395 }
1396
1397
1398
1399 double integ_lv(float *lv,float *theta)
1400 {
1401 int i;
1402 double buffer=0.0;
1403
1404 for (i=0;i<145;i++)
1405 {
1406 buffer += (*(lv+i))*cos(radians(*(theta+i)));
1407 }
1408
1409 return buffer*2*M_PI/144;
1410 }
1411
1412
1413
1414 /* enter day number(double), return E0 = square(R0/R): eccentricity correction factor */
1415
1416 double get_eccentricity()
1417 {
1418 double day_angle;
1419 double E0;
1420
1421 day_angle = 2*M_PI*(daynumber - 1)/365;
1422 E0 = 1.00011+0.034221*cos(day_angle)+0.00128*sin(day_angle)+
1423 0.000719*cos(2*day_angle)+0.000077*sin(2*day_angle);
1424
1425 return (E0);
1426 }
1427
1428
1429 /* enter sunzenith angle (degrees) return relative air mass (double) */
1430 double air_mass()
1431 {
1432 double m;
1433 if (sunzenith>90)
1434 {
1435 if(suppress_warnings==0)
1436 { fprintf(stderr, "Warning: air mass has reached the maximal value\n"); }
1437 sunzenith=90;
1438 }
1439 m = 1/( cos(sunzenith*M_PI/180)+0.15*exp( log(93.885-sunzenith)*(-1.253) ) );
1440 return(m);
1441 }
1442
1443
1444