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root/radiance/ray/src/gen/gendaylit.c
Revision: 2.3
Committed: Sat Jun 20 21:34:34 2009 UTC (14 years, 10 months ago) by greg
Content type: text/plain
Branch: MAIN
CVS Tags: rad4R0
Changes since 2.2: +4 -2 lines
Log Message:
Eliminated debug message

File Contents

# User Rev Content
1 greg 2.1 #ifndef lint
2 greg 2.3 static const char RCSid[] = "$Id: gendaylit.c,v 2.2 2009/06/15 22:27:21 greg Exp $";
3 greg 2.1 #endif
4     /* Copyright (c) 1994 *Fraunhofer Institut for Solar Energy Systems
5     * Oltmannstr 5, D-79100 Freiburg, Germany
6     * *Agence de l'Environnement et de la Maitrise de l'Energie
7     * Centre de Valbonne, 500 route des Lucioles, 06565 Sophia Antipolis Cedex, France
8     * *BOUYGUES
9     * 1 Avenue Eugene Freyssinet, Saint-Quentin-Yvelines, France
10     */
11    
12    
13    
14     /*
15     * gendaylit.c program to generate the angular distribution of the daylight.
16     * Our zenith is along the Z-axis, the X-axis
17     * points east, and the Y-axis points north.
18     */
19    
20     #include <stdio.h>
21     #include <string.h>
22     #include <math.h>
23     #include <stdlib.h>
24 greg 2.2 #include <ctype.h>
25 greg 2.1
26     #include "rtio.h"
27     #include "fvect.h"
28     #include "color.h"
29     #include "paths.h"
30    
31     extern int jdate(int month, int day);
32     extern double stadj(int jd);
33     extern double sdec(int jd);
34     extern double salt(double sd, double st);
35     extern double sazi(double sd, double st);
36    
37     double normsc();
38    
39     #define DATFILE "coeff_perez.dat"
40    
41    
42    
43     /* Perez sky parametrization : epsilon and delta calculations from the direct and diffuse irradiances */
44     double sky_brightness();
45     double sky_clearness();
46    
47     /* calculation of the direct and diffuse components from the Perez parametrization */
48     double diffus_irradiance_from_sky_brightness();
49     double direct_irradiance_from_sky_clearness();
50    
51    
52     /* Perez global horizontal, diffuse horizontal and direct normal luminous efficacy models : input w(cm)=2cm, solar zenith angle(degrees); output efficacy(lm/W) */
53     double glob_h_effi_PEREZ();
54     double glob_h_diffuse_effi_PEREZ();
55     double direct_n_effi_PEREZ();
56     /*likelihood check of the epsilon, delta, direct and diffuse components*/
57     void check_parametrization();
58     void check_irradiances();
59     void check_illuminances();
60     void illu_to_irra_index();
61    
62    
63     /* Perez sky luminance model */
64     int lect_coeff_perez(char *filename,float **coeff_perez);
65     double calc_rel_lum_perez(double dzeta,double gamma,double Z,
66     double epsilon,double Delta,float *coeff_perez);
67     /* coefficients for the sky luminance perez model */
68     void coeff_lum_perez(double Z, double epsilon, double Delta, float *coeff_perez);
69     double radians(double degres);
70     double degres(double radians);
71     void theta_phi_to_dzeta_gamma(double theta,double phi,double *dzeta,double *gamma, double Z);
72     double integ_lv(float *lv,float *theta);
73     float *theta_ordered(char *filename);
74     float *phi_ordered(char *filename);
75 greg 2.2 void skip_comments(FILE *fp);
76 greg 2.1
77    
78    
79     /* astronomy and geometry*/
80     double get_eccentricity();
81     double air_mass();
82     double get_angle_sun_direction(double sun_zenith, double sun_azimut, double direction_zenith, double direction_azimut);
83    
84    
85     /* date*/
86     int jdate(int month, int day);
87    
88    
89    
90    
91    
92     /* sun calculation constants */
93     extern double s_latitude;
94     extern double s_longitude;
95     extern double s_meridian;
96    
97     const double AU = 149597890E3;
98     const double solar_constant_e = 1367; /* solar constant W/m^2 */
99     const double solar_constant_l = 127.5; /* solar constant klux */
100    
101     const double half_sun_angle = 0.2665;
102     const double half_direct_angle = 2.85;
103    
104     const double skyclearinf = 1.000; /* limitations for the variation of the Perez parameters */
105     const double skyclearsup = 12.1;
106     const double skybriginf = 0.01;
107     const double skybrigsup = 0.6;
108    
109    
110    
111     /* required values */
112     int month, day; /* date */
113     double hour; /* time */
114     int tsolar; /* 0=standard, 1=solar */
115     double altitude, azimuth; /* or solar angles */
116    
117    
118    
119     /* definition of the sky conditions through the Perez parametrization */
120     double skyclearness, skybrightness;
121     double solarradiance; /*radiance of the sun disk and of the circumsolar area*/
122     double diffusilluminance, directilluminance, diffusirradiance, directirradiance;
123     double sunzenith, daynumber=150, atm_preci_water=2;
124    
125     double diffnormalization, dirnormalization;
126     double *c_perez;
127    
128     int output=0; /*define the unit of the output (sky luminance or radiance): visible watt=0, solar watt=1, lumen=2*/
129     int input=0; /*define the input for the calulation*/
130    
131     /* default values */
132     int cloudy = 0; /* 1=standard, 2=uniform */
133     int dosun = 1;
134     double zenithbr = -1.0;
135     double betaturbidity = 0.1;
136     double gprefl = 0.2;
137     int S_INTER=0;
138    
139     /* computed values */
140     double sundir[3];
141     double groundbr;
142     double F2;
143     double solarbr = 0.0;
144     int u_solar = 0; /* -1=irradiance, 1=radiance */
145    
146     char *progname;
147     char errmsg[128];
148    
149    
150     main(argc, argv)
151     int argc;
152     char *argv[];
153     {
154     int i;
155    
156     progname = argv[0];
157     if (argc == 2 && !strcmp(argv[1], "-defaults")) {
158     printdefaults();
159     exit(0);
160     }
161     if (argc < 4)
162     userror("arg count");
163     if (!strcmp(argv[1], "-ang")) {
164     altitude = atof(argv[2]) * (M_PI/180);
165     azimuth = atof(argv[3]) * (M_PI/180);
166     month = 0;
167     } else {
168     month = atoi(argv[1]);
169     if (month < 1 || month > 12)
170     userror("bad month");
171     day = atoi(argv[2]);
172     if (day < 1 || day > 31)
173     userror("bad day");
174     hour = atof(argv[3]);
175     if (hour < 0 || hour >= 24)
176     userror("bad hour");
177     tsolar = argv[3][0] == '+';
178     }
179     for (i = 4; i < argc; i++)
180     if (argv[i][0] == '-' || argv[i][0] == '+')
181     switch (argv[i][1]) {
182     case 's':
183     cloudy = 0;
184     dosun = argv[i][0] == '+';
185     break;
186     case 'r':
187     case 'R':
188     u_solar = argv[i][1] == 'R' ? -1 : 1;
189     solarbr = atof(argv[++i]);
190     break;
191     case 'c':
192     cloudy = argv[i][0] == '+' ? 2 : 1;
193     dosun = 0;
194     break;
195     case 't':
196     betaturbidity = atof(argv[++i]);
197     break;
198     case 'b':
199     zenithbr = atof(argv[++i]);
200     break;
201     case 'g':
202     gprefl = atof(argv[++i]);
203     break;
204     case 'a':
205     s_latitude = atof(argv[++i]) * (M_PI/180);
206     break;
207     case 'o':
208     s_longitude = atof(argv[++i]) * (M_PI/180);
209     break;
210     case 'm':
211     s_meridian = atof(argv[++i]) * (M_PI/180);
212     break;
213    
214    
215     case 'O':
216     output = atof(argv[++i]); /*define the unit of the output of the program :
217     sky and sun luminance/radiance (0==W visible, 1==W solar radiation, 2==lm)
218     default is set to 0*/
219     break;
220    
221     case 'P':
222     input = 0; /* Perez parameters: epsilon, delta */
223     skyclearness = atof(argv[++i]);
224     skybrightness = atof(argv[++i]);
225     break;
226    
227     case 'W': /* direct normal Irradiance [W/m^2] */
228     input = 1; /* diffuse horizontal Irrad. [W/m^2] */
229     directirradiance = atof(argv[++i]);
230     diffusirradiance = atof(argv[++i]);
231     break;
232    
233     case 'L': /* direct normal Illuminance [Lux] */
234     input = 2; /* diffuse horizontal Ill. [Lux] */
235     directilluminance = atof(argv[++i]);
236     diffusilluminance = atof(argv[++i]);
237     break;
238    
239     case 'G': /* direct horizontal Irradiance [W/m^2] */
240     input = 3; /* diffuse horizontal Irrad. [W/m^2] */
241     directirradiance = atof(argv[++i]);
242     diffusirradiance = atof(argv[++i]);
243     break;
244    
245    
246     default:
247     sprintf(errmsg, "unknown option: %s", argv[i]);
248     userror(errmsg);
249     }
250     else
251     userror("bad option");
252    
253     if (fabs(s_meridian-s_longitude) > 30*M_PI/180)
254     fprintf(stderr,
255     "%s: warning: %.1f hours btwn. standard meridian and longitude\n",
256     progname, (s_longitude-s_meridian)*12/M_PI);
257    
258    
259     /* allocation dynamique de memoire pour les pointeurs */
260     if ( (c_perez = malloc(5*sizeof(double))) == NULL )
261     {
262     fprintf(stderr,"Out of memory error in function main !");
263     exit(1);
264     }
265    
266    
267     printhead(argc, argv);
268    
269     computesky();
270     printsky();
271    
272     exit(0);
273     }
274    
275    
276     computesky() /* compute sky parameters */
277     {
278    
279     /* new variables */
280     int j, i;
281     float *lv_mod; /* 145 luminance values*/
282     /* 145 directions for the calculation of the normalization coefficient, coefficient Perez model */
283     float *theta_o, *phi_o, *coeff_perez;
284     double dzeta, gamma;
285     double diffusion;
286     double normfactor;
287    
288    
289    
290     /* compute solar direction */
291    
292     if (month) { /* from date and time */
293     int jd;
294     double sd, st;
295    
296     jd = jdate(month, day); /* Julian date */
297     sd = sdec(jd); /* solar declination */
298     if (tsolar) /* solar time */
299     st = hour;
300     else
301     st = hour + stadj(jd);
302     altitude = salt(sd, st);
303     azimuth = sazi(sd, st);
304    
305     daynumber = (double)jdate(month, day);
306    
307     }
308     if (!cloudy && altitude > 87.*M_PI/180.) {
309     fprintf(stderr,
310     "%s: warning - sun too close to zenith, reducing altitude to 87 degrees\n",
311     progname);
312     printf(
313     "# warning - sun too close to zenith, reducing altitude to 87 degrees\n");
314     altitude = 87.*M_PI/180.;
315     }
316     sundir[0] = -sin(azimuth)*cos(altitude);
317     sundir[1] = -cos(azimuth)*cos(altitude);
318     sundir[2] = sin(altitude);
319    
320    
321     /* calculation for the new functions */
322     sunzenith = 90 - altitude*180/M_PI;
323    
324    
325    
326     /* compute the inputs for the calculation of the light distribution over the sky*/
327     if (input==0)
328     {
329     check_parametrization();
330     diffusirradiance = diffus_irradiance_from_sky_brightness(); /*diffuse horizontal irradiance*/
331     directirradiance = direct_irradiance_from_sky_clearness();
332     check_irradiances();
333    
334     if (output==0 || output==2)
335     {
336     diffusilluminance = diffusirradiance*glob_h_diffuse_effi_PEREZ();/*diffuse horizontal illuminance*/
337     directilluminance = directirradiance*direct_n_effi_PEREZ();
338     check_illuminances();
339     }
340     }
341    
342    
343     else if (input==1)
344     {
345     check_irradiances();
346     skybrightness = sky_brightness();
347     skyclearness = sky_clearness();
348     check_parametrization();
349    
350     if (output==0 || output==2)
351     {
352     diffusilluminance = diffusirradiance*glob_h_diffuse_effi_PEREZ();/*diffuse horizontal illuminance*/
353     directilluminance = directirradiance*direct_n_effi_PEREZ();
354     check_illuminances();
355     }
356    
357     }
358    
359    
360     else if (input==2)
361     {
362     check_illuminances();
363     illu_to_irra_index();
364     check_parametrization();
365     }
366    
367    
368     else if (input==3)
369     {
370     if (altitude<=0)
371     {
372     fprintf(stderr, "solar zenith angle larger than 90� \n the models used are not more valid\n");
373     exit(1);
374     }
375    
376     directirradiance=directirradiance/sin(altitude);
377     check_irradiances();
378     skybrightness = sky_brightness();
379     skyclearness = sky_clearness();
380     check_parametrization();
381    
382     if (output==0 || output==2)
383     {
384     diffusilluminance = diffusirradiance*glob_h_diffuse_effi_PEREZ();/*diffuse horizontal illuminance*/
385     directilluminance = directirradiance*direct_n_effi_PEREZ();
386     check_illuminances();
387     }
388    
389     }
390    
391    
392     else {fprintf(stderr,"error in giving the input arguments"); exit(1);}
393    
394    
395    
396     /* normalization factor for the relative sky luminance distribution, diffuse part*/
397    
398     /* allocation dynamique de memoire pour les pointeurs */
399     if ( (coeff_perez = malloc(8*20*sizeof(float))) == NULL )
400     {
401     fprintf(stderr,"Out of memory error in function main !");
402     exit(1);
403     }
404    
405     /* read the coefficients for the Perez sky luminance model */
406     if (lect_coeff_perez(DATFILE, &coeff_perez) > 0)
407     {
408     fprintf(stderr,"lect_coeff_perez does not work\n");
409     exit(2);
410     }
411    
412     if ( (lv_mod = malloc(145*sizeof(float))) == NULL)
413     {
414     fprintf(stderr,"Out of memory in function main");
415     exit(1);
416     }
417    
418     /* read the angles */
419     theta_o = theta_ordered("defangle.dat");
420     phi_o = phi_ordered("defangle.dat");
421    
422     /* parameters for the perez model */
423     coeff_lum_perez(radians(sunzenith), skyclearness, skybrightness, coeff_perez);
424    
425     /*calculation of the modelled luminance */
426     for (j=0;j<145;j++)
427     {
428     theta_phi_to_dzeta_gamma(radians(*(theta_o+j)),radians(*(phi_o+j)),&dzeta,&gamma,radians(sunzenith));
429     *(lv_mod+j) = calc_rel_lum_perez(dzeta,gamma,radians(sunzenith),skyclearness,skybrightness,coeff_perez);
430     /*printf("theta, phi, lv_mod %lf\t %lf\t %lf\n", *(theta_o+j),*(phi_o+j),*(lv_mod+j));*/
431     }
432    
433     /* integration of luminance for the normalization factor, diffuse part of the sky*/
434     diffnormalization = integ_lv(lv_mod, theta_o);
435     /*printf("perez integration %lf\n", diffnormalization);*/
436    
437    
438    
439    
440     /*normalization coefficient in lumen or in watt*/
441     if (output==0)
442     {
443     diffnormalization = diffusilluminance/diffnormalization/WHTEFFICACY;
444     }
445     else if (output==1)
446     {
447     diffnormalization = diffusirradiance/diffnormalization;
448     }
449     else if (output==2)
450     {
451     diffnormalization = diffusilluminance/diffnormalization;
452     }
453    
454     else {fprintf(stderr,"output argument : wrong number"); exit(1);}
455    
456    
457    
458    
459     /* calculation for the solar source */
460     if (output==0)
461     solarradiance = directilluminance/(2*M_PI*(1-cos(half_sun_angle*M_PI/180)))/WHTEFFICACY;
462    
463     else if (output==1)
464     solarradiance = directirradiance/(2*M_PI*(1-cos(half_sun_angle*M_PI/180)));
465    
466     else
467     solarradiance = directilluminance/(2*M_PI*(1-cos(half_sun_angle*M_PI/180)));
468    
469    
470    
471    
472     /* Compute the ground radiance */
473     zenithbr=calc_rel_lum_perez(0.0,radians(sunzenith),radians(sunzenith),skyclearness,skybrightness,coeff_perez);
474     zenithbr*=diffnormalization;
475 greg 2.3 /*
476 greg 2.1 fprintf(stderr, "gendaylit : the actual zenith radiance(W/m^2/sr) or luminance(cd/m^2) is : %.0lf\n", zenithbr);
477 greg 2.3 */
478    
479 greg 2.1 if (skyclearness==1)
480     normfactor = 0.777778;
481    
482     if (skyclearness>=6)
483     {
484     F2 = 0.274*(0.91 + 10.0*exp(-3.0*(M_PI/2.0-altitude)) + 0.45*sundir[2]*sundir[2]);
485     normfactor = normsc()/F2/M_PI;
486     }
487    
488     if ( (skyclearness>1) && (skyclearness<6) )
489     {
490     S_INTER=1;
491     F2 = (2.739 + .9891*sin(.3119+2.6*altitude)) * exp(-(M_PI/2.0-altitude)*(.4441+1.48*altitude));
492     normfactor = normsc()/F2/M_PI;
493     }
494    
495     groundbr = zenithbr*normfactor;
496     printf("# Ground ambient level: %.1f\n", groundbr);
497    
498     if (dosun&&(skyclearness>1))
499     groundbr += 6.8e-5/M_PI*solarradiance*sundir[2];
500    
501     groundbr *= gprefl;
502    
503    
504    
505     return;
506     }
507    
508    
509    
510    
511    
512    
513    
514     printsky() /* print out sky */
515     {
516     if (dosun&&(skyclearness>1))
517     {
518     printf("\nvoid light solar\n");
519     printf("0\n0\n");
520     printf("3 %.3e %.3e %.3e\n", solarradiance, solarradiance, solarradiance);
521     printf("\nsolar source sun\n");
522     printf("0\n0\n");
523     printf("4 %f %f %f %f\n", sundir[0], sundir[1], sundir[2], 2*half_sun_angle);
524     }
525    
526     if (dosun&&(skyclearness==1))
527     {
528     printf("\nvoid light solar\n");
529     printf("0\n0\n");
530     printf("3 0.0 0.0 0.0\n");
531     printf("\nsolar source sun\n");
532     printf("0\n0\n");
533     printf("4 %f %f %f %f\n", sundir[0], sundir[1], sundir[2], 2*half_sun_angle);
534     }
535    
536    
537     printf("\nvoid brightfunc skyfunc\n");
538     printf("2 skybright perezlum.cal\n");
539     printf("0\n");
540     printf("10 %.3e %.3e %lf %lf %lf %lf %lf %f %f %f \n", diffnormalization, groundbr,
541     *(c_perez+0),*(c_perez+1),*(c_perez+2),*(c_perez+3),*(c_perez+4),
542     sundir[0], sundir[1], sundir[2]);
543     }
544    
545    
546     printdefaults() /* print default values */
547     {
548     printf("-g %f\t\t\t# Ground plane reflectance\n", gprefl);
549     if (zenithbr > 0.0)
550     printf("-b %f\t\t\t# Zenith radiance (watts/ster/m^2\n", zenithbr);
551     else
552     printf("-t %f\t\t\t# Atmospheric betaturbidity\n", betaturbidity);
553     printf("-a %f\t\t\t# Site latitude (degrees)\n", s_latitude*(180/M_PI));
554     printf("-o %f\t\t\t# Site longitude (degrees)\n", s_longitude*(180/M_PI));
555     printf("-m %f\t\t\t# Standard meridian (degrees)\n", s_meridian*(180/M_PI));
556     }
557    
558    
559     userror(msg) /* print usage error and quit */
560     char *msg;
561     {
562     if (msg != NULL)
563     fprintf(stderr, "%s: Use error - %s\n", progname, msg);
564     fprintf(stderr, "Usage: %s month day hour [-P|-W|-L] direct_value diffus_value [options]\n", progname);
565     fprintf(stderr, "or : %s -ang altitude azimuth [-P|-W|-L] direct_value diffus_value [options]\n", progname);
566     fprintf(stderr, " -P epsilon delta (these are the Perez parameters) \n");
567     fprintf(stderr, " -W direct-normal-irradiance diffuse-horizontal-irradiance (W/m^2)\n");
568     fprintf(stderr, " -L direct-normal-illuminance diffuse-horizontal-illuminance (lux)\n");
569     fprintf(stderr, " -G direct-horizontal-irradiance diffuse-horizontal-irradiance (W/m^2)\n");
570     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");
571     exit(1);
572     }
573    
574    
575    
576     double
577     normsc() /* compute normalization factor (E0*F2/L0) */
578     {
579     static double nfc[2][5] = {
580     /* clear sky approx. */
581     {2.766521, 0.547665, -0.369832, 0.009237, 0.059229},
582     /* intermediate sky approx. */
583     {3.5556, -2.7152, -1.3081, 1.0660, 0.60227},
584     };
585     register double *nf;
586     double x, nsc;
587     register int i;
588     /* polynomial approximation */
589     nf = nfc[S_INTER];
590     x = (altitude - M_PI/4.0)/(M_PI/4.0);
591     nsc = nf[i=4];
592     while (i--)
593     nsc = nsc*x + nf[i];
594    
595     return(nsc);
596     }
597    
598    
599    
600     printhead(ac, av) /* print command header */
601     register int ac;
602     register char **av;
603     {
604     putchar('#');
605     while (ac--) {
606     putchar(' ');
607     fputs(*av++, stdout);
608     }
609     putchar('\n');
610     }
611    
612    
613    
614    
615 greg 2.2 void
616     skip_comments(FILE *fp) /* skip comments in file */
617     {
618     int c;
619    
620     while ((c = getc(fp)) != EOF)
621     if (c == '#') {
622     while ((c = getc(fp)) != EOF)
623     if (c == '\n')
624     break;
625     } else if (!isspace(c)) {
626     ungetc(c, fp);
627     break;
628     }
629     }
630 greg 2.1
631    
632    
633     /* Perez models */
634    
635     /* Perez global horizontal luminous efficacy model */
636     double glob_h_effi_PEREZ()
637     {
638    
639     double value;
640     double category_bounds[10], a[10], b[10], c[10], d[10];
641     int category_total_number, category_number, i;
642    
643    
644     if (skyclearness<skyclearinf || skyclearness>skyclearsup || skybrightness<=skybriginf || skybrightness>skybrigsup)
645     fprintf(stderr, "Warning : skyclearness or skybrightness out of range ; \n Check your input parameters\n");
646    
647     /* initialize category bounds (clearness index bounds) */
648    
649     category_total_number = 8;
650    
651     category_bounds[1] = 1;
652     category_bounds[2] = 1.065;
653     category_bounds[3] = 1.230;
654     category_bounds[4] = 1.500;
655     category_bounds[5] = 1.950;
656     category_bounds[6] = 2.800;
657     category_bounds[7] = 4.500;
658     category_bounds[8] = 6.200;
659     category_bounds[9] = 12.01;
660    
661    
662     /* initialize model coefficients */
663     a[1] = 96.63;
664     a[2] = 107.54;
665     a[3] = 98.73;
666     a[4] = 92.72;
667     a[5] = 86.73;
668     a[6] = 88.34;
669     a[7] = 78.63;
670     a[8] = 99.65;
671    
672     b[1] = -0.47;
673     b[2] = 0.79;
674     b[3] = 0.70;
675     b[4] = 0.56;
676     b[5] = 0.98;
677     b[6] = 1.39;
678     b[7] = 1.47;
679     b[8] = 1.86;
680    
681     c[1] = 11.50;
682     c[2] = 1.79;
683     c[3] = 4.40;
684     c[4] = 8.36;
685     c[5] = 7.10;
686     c[6] = 6.06;
687     c[7] = 4.93;
688     c[8] = -4.46;
689    
690     d[1] = -9.16;
691     d[2] = -1.19;
692     d[3] = -6.95;
693     d[4] = -8.31;
694     d[5] = -10.94;
695     d[6] = -7.60;
696     d[7] = -11.37;
697     d[8] = -3.15;
698    
699    
700    
701    
702     for (i=1; i<=category_total_number; i++)
703     {
704     if ( (skyclearness >= category_bounds[i]) && (skyclearness < category_bounds[i+1]) )
705     category_number = i;
706     }
707    
708     value = a[category_number] + b[category_number]*atm_preci_water +
709     c[category_number]*cos(sunzenith*M_PI/180) + d[category_number]*log(skybrightness);
710    
711     return(value);
712     }
713    
714    
715     /* global horizontal diffuse efficacy model, according to PEREZ */
716     double glob_h_diffuse_effi_PEREZ()
717     {
718     double value;
719     double category_bounds[10], a[10], b[10], c[10], d[10];
720     int category_total_number, category_number, i;
721    
722    
723     if (skyclearness<skyclearinf || skyclearness>skyclearsup || skybrightness<=skybriginf || skybrightness>skybrigsup)
724     fprintf(stderr, "Warning : skyclearness or skybrightness out of range ; \n Check your input parameters\n");
725    
726     /* initialize category bounds (clearness index bounds) */
727    
728     category_total_number = 8;
729    
730     category_bounds[1] = 1;
731     category_bounds[2] = 1.065;
732     category_bounds[3] = 1.230;
733     category_bounds[4] = 1.500;
734     category_bounds[5] = 1.950;
735     category_bounds[6] = 2.800;
736     category_bounds[7] = 4.500;
737     category_bounds[8] = 6.200;
738     category_bounds[9] = 12.01;
739    
740    
741     /* initialize model coefficients */
742     a[1] = 97.24;
743     a[2] = 107.22;
744     a[3] = 104.97;
745     a[4] = 102.39;
746     a[5] = 100.71;
747     a[6] = 106.42;
748     a[7] = 141.88;
749     a[8] = 152.23;
750    
751     b[1] = -0.46;
752     b[2] = 1.15;
753     b[3] = 2.96;
754     b[4] = 5.59;
755     b[5] = 5.94;
756     b[6] = 3.83;
757     b[7] = 1.90;
758     b[8] = 0.35;
759    
760     c[1] = 12.00;
761     c[2] = 0.59;
762     c[3] = -5.53;
763     c[4] = -13.95;
764     c[5] = -22.75;
765     c[6] = -36.15;
766     c[7] = -53.24;
767     c[8] = -45.27;
768    
769     d[1] = -8.91;
770     d[2] = -3.95;
771     d[3] = -8.77;
772     d[4] = -13.90;
773     d[5] = -23.74;
774     d[6] = -28.83;
775     d[7] = -14.03;
776     d[8] = -7.98;
777    
778    
779    
780    
781     for (i=1; i<=category_total_number; i++)
782     {
783     if ( (skyclearness >= category_bounds[i]) && (skyclearness < category_bounds[i+1]) )
784     category_number = i;
785     }
786    
787     value = a[category_number] + b[category_number]*atm_preci_water + c[category_number]*cos(sunzenith*M_PI/180) +
788     d[category_number]*log(skybrightness);
789    
790     return(value);
791     }
792    
793    
794     /* direct normal efficacy model, according to PEREZ */
795    
796     double direct_n_effi_PEREZ()
797    
798     {
799     double value;
800     double category_bounds[10], a[10], b[10], c[10], d[10];
801     int category_total_number, category_number, i;
802    
803    
804     if (skyclearness<skyclearinf || skyclearness>skyclearsup || skybrightness<=skybriginf || skybrightness>skybrigsup)
805     fprintf(stderr, "Warning : skyclearness or skybrightness out of range ; \n Check your input parameters\n");
806    
807    
808     /* initialize category bounds (clearness index bounds) */
809    
810     category_total_number = 8;
811    
812     category_bounds[1] = 1;
813     category_bounds[2] = 1.065;
814     category_bounds[3] = 1.230;
815     category_bounds[4] = 1.500;
816     category_bounds[5] = 1.950;
817     category_bounds[6] = 2.800;
818     category_bounds[7] = 4.500;
819     category_bounds[8] = 6.200;
820     category_bounds[9] = 12.1;
821    
822    
823     /* initialize model coefficients */
824     a[1] = 57.20;
825     a[2] = 98.99;
826     a[3] = 109.83;
827     a[4] = 110.34;
828     a[5] = 106.36;
829     a[6] = 107.19;
830     a[7] = 105.75;
831     a[8] = 101.18;
832    
833     b[1] = -4.55;
834     b[2] = -3.46;
835     b[3] = -4.90;
836     b[4] = -5.84;
837     b[5] = -3.97;
838     b[6] = -1.25;
839     b[7] = 0.77;
840     b[8] = 1.58;
841    
842     c[1] = -2.98;
843     c[2] = -1.21;
844     c[3] = -1.71;
845     c[4] = -1.99;
846     c[5] = -1.75;
847     c[6] = -1.51;
848     c[7] = -1.26;
849     c[8] = -1.10;
850    
851     d[1] = 117.12;
852     d[2] = 12.38;
853     d[3] = -8.81;
854     d[4] = -4.56;
855     d[5] = -6.16;
856     d[6] = -26.73;
857     d[7] = -34.44;
858     d[8] = -8.29;
859    
860    
861    
862     for (i=1; i<=category_total_number; i++)
863     {
864     if ( (skyclearness >= category_bounds[i]) && (skyclearness < category_bounds[i+1]) )
865     category_number = i;
866     }
867    
868     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;
869    
870     if (value < 0) value = 0;
871    
872     return(value);
873     }
874    
875    
876     /*check the range of epsilon and delta indexes of the perez parametrization*/
877     void check_parametrization()
878     {
879     if (skyclearness<skyclearinf || skyclearness>skyclearsup || skybrightness<=skybriginf || skybrightness>skybrigsup)
880     {
881     fprintf(stderr,"sky clearness or sky brightness out of range %lf\t %lf\n", skyclearness, skybrightness);
882     exit(1);
883     }
884     else return;
885     }
886    
887    
888     /* likelihood of the direct and diffuse components */
889     void check_illuminances()
890     {
891     if (!( (directilluminance>=0) && (directilluminance<=solar_constant_l*1000) && (diffusilluminance>0) ))
892     {
893     fprintf(stderr,"direct or diffuse illuminances out of range\n");
894     exit(1);
895     }
896     return;
897     }
898    
899    
900     void check_irradiances()
901     {
902     if (!( (directirradiance>=0) && (directirradiance<=solar_constant_e) && (diffusirradiance>0) ))
903     {
904     fprintf(stderr,"direct or diffuse irradiances out of range\n");
905     exit(1);
906     }
907     return;
908     }
909    
910    
911    
912     /* Perez sky's brightness */
913     double sky_brightness()
914     {
915     double value;
916    
917     value = diffusirradiance * air_mass() / ( solar_constant_e*get_eccentricity());
918    
919     return(value);
920     }
921    
922    
923     /* Perez sky's clearness */
924     double sky_clearness()
925     {
926     double value;
927    
928     value = ( (diffusirradiance + directirradiance)/(diffusirradiance) + 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) ;
929    
930     return(value);
931     }
932    
933    
934    
935     /* diffus horizontal irradiance from Perez sky's brightness */
936     double diffus_irradiance_from_sky_brightness()
937     {
938     double value;
939    
940     value = skybrightness / air_mass() * ( solar_constant_e*get_eccentricity());
941    
942     return(value);
943     }
944    
945    
946     /* direct normal irradiance from Perez sky's clearness */
947     double direct_irradiance_from_sky_clearness()
948     {
949     double value;
950    
951     value = diffus_irradiance_from_sky_brightness();
952     value = value * ( (skyclearness-1) * (1+1.041*sunzenith*M_PI/180*sunzenith*M_PI/180*sunzenith*M_PI/180) );
953    
954     return(value);
955     }
956    
957    
958     void illu_to_irra_index(void)
959     {
960     double test1=0.1, test2=0.1;
961     int counter=0;
962    
963     diffusirradiance = diffusilluminance*solar_constant_e/(solar_constant_l*1000);
964     directirradiance = directilluminance*solar_constant_e/(solar_constant_l*1000);
965     skyclearness = sky_clearness();
966     skybrightness = sky_brightness();
967     if (skyclearness>12) skyclearness=12;
968     if (skybrightness<0.05) skybrightness=0.01;
969    
970    
971     while ( ((fabs(diffusirradiance-test1)>10) || (fabs(directirradiance-test2)>10)
972     || skyclearness>skyclearinf || skyclearness<skyclearsup
973     || skybrightness>skybriginf || skybrightness<skybrigsup )
974     && !(counter==5) )
975     {
976     /*fprintf(stderr, "conversion illuminance into irradiance %lf\t %lf\n", diffusirradiance, directirradiance);*/
977    
978     test1=diffusirradiance;
979     test2=directirradiance;
980     counter++;
981    
982     diffusirradiance = diffusilluminance/glob_h_diffuse_effi_PEREZ();
983     directirradiance = directilluminance/direct_n_effi_PEREZ();
984     /*fprintf(stderr, "conversion illuminance into irradiance %lf\t %lf\n", diffusirradiance, directirradiance);*/
985    
986     skybrightness = sky_brightness();
987     skyclearness = sky_clearness();
988     if (skyclearness>12) skyclearness=12;
989     if (skybrightness<0.05) skybrightness=0.01;
990    
991     /*fprintf(stderr, "%lf\t %lf\n", skybrightness, skyclearness);*/
992    
993     }
994    
995    
996     return;
997     }
998    
999    
1000     int lect_coeff_perez(char *filename,float **coeff_perez)
1001     {
1002     FILE *fcoeff_perez;
1003     float temp;
1004     int i,j;
1005    
1006     if ((fcoeff_perez = frlibopen(filename)) == NULL)
1007     {
1008     fprintf(stderr,"file %s cannot be opened\n", filename);
1009     return 1; /* il y a un probleme de fichier */
1010     }
1011     else
1012     {
1013     /*printf("file %s open\n", filename);*/
1014     }
1015 greg 2.2
1016     skip_comments(fcoeff_perez);
1017 greg 2.1
1018     for (i=0;i<8;i++)
1019     for (j=0;j<20;j++)
1020     {
1021     fscanf(fcoeff_perez,"%f",&temp);
1022     *(*coeff_perez+i*20+j) = temp;
1023     }
1024     fclose(fcoeff_perez);
1025    
1026     return 0; /* tout est OK */
1027     }
1028    
1029    
1030    
1031     /* sky luminance perez model */
1032     double calc_rel_lum_perez(double dzeta,double gamma,double Z,
1033     double epsilon,double Delta,float *coeff_perez)
1034     {
1035     float x[5][4];
1036     int i,j,num_lin;
1037     double c_perez[5];
1038    
1039     if ( (epsilon < skyclearinf) || (epsilon >= skyclearsup) )
1040     {
1041     fprintf(stderr,"Epsilon out of range in function calc_rel_lum_perez !\n");
1042     exit(1);
1043     }
1044    
1045     /* correction de modele de Perez solar energy ...*/
1046     if ( (epsilon > 1.065) && (epsilon < 2.8) )
1047     {
1048     if ( Delta < 0.2 ) Delta = 0.2;
1049     }
1050    
1051     if ( (epsilon >= 1.000) && (epsilon < 1.065) ) num_lin = 0;
1052     if ( (epsilon >= 1.065) && (epsilon < 1.230) ) num_lin = 1;
1053     if ( (epsilon >= 1.230) && (epsilon < 1.500) ) num_lin = 2;
1054     if ( (epsilon >= 1.500) && (epsilon < 1.950) ) num_lin = 3;
1055     if ( (epsilon >= 1.950) && (epsilon < 2.800) ) num_lin = 4;
1056     if ( (epsilon >= 2.800) && (epsilon < 4.500) ) num_lin = 5;
1057     if ( (epsilon >= 4.500) && (epsilon < 6.200) ) num_lin = 6;
1058     if ( (epsilon >= 6.200) && (epsilon < 14.00) ) num_lin = 7;
1059    
1060     for (i=0;i<5;i++)
1061     for (j=0;j<4;j++)
1062     {
1063     x[i][j] = *(coeff_perez + 20*num_lin + 4*i +j);
1064     /* printf("x %d %d vaut %f\n",i,j,x[i][j]); */
1065     }
1066    
1067    
1068     if (num_lin)
1069     {
1070     for (i=0;i<5;i++)
1071     c_perez[i] = x[i][0] + x[i][1]*Z + Delta * (x[i][2] + x[i][3]*Z);
1072     }
1073     else
1074     {
1075     c_perez[0] = x[0][0] + x[0][1]*Z + Delta * (x[0][2] + x[0][3]*Z);
1076     c_perez[1] = x[1][0] + x[1][1]*Z + Delta * (x[1][2] + x[1][3]*Z);
1077     c_perez[4] = x[4][0] + x[4][1]*Z + Delta * (x[4][2] + x[4][3]*Z);
1078     c_perez[2] = exp( pow(Delta*(x[2][0]+x[2][1]*Z),x[2][2])) - x[2][3];
1079     c_perez[3] = -exp( Delta*(x[3][0]+x[3][1]*Z) )+x[3][2]+Delta*x[3][3];
1080     }
1081    
1082    
1083     return (1 + c_perez[0]*exp(c_perez[1]/cos(dzeta)) ) *
1084     (1 + c_perez[2]*exp(c_perez[3]*gamma) +
1085     c_perez[4]*cos(gamma)*cos(gamma) );
1086     }
1087    
1088    
1089    
1090     /* coefficients for the sky luminance perez model */
1091     void coeff_lum_perez(double Z, double epsilon, double Delta, float *coeff_perez)
1092     {
1093     float x[5][4];
1094     int i,j,num_lin;
1095    
1096     if ( (epsilon < skyclearinf) || (epsilon >= skyclearsup) )
1097     {
1098     fprintf(stderr,"Epsilon out of range in function calc_rel_lum_perez !\n");
1099     exit(1);
1100     }
1101    
1102     /* correction du modele de Perez solar energy ...*/
1103     if ( (epsilon > 1.065) && (epsilon < 2.8) )
1104     {
1105     if ( Delta < 0.2 ) Delta = 0.2;
1106     }
1107    
1108     if ( (epsilon >= 1.000) && (epsilon < 1.065) ) num_lin = 0;
1109     if ( (epsilon >= 1.065) && (epsilon < 1.230) ) num_lin = 1;
1110     if ( (epsilon >= 1.230) && (epsilon < 1.500) ) num_lin = 2;
1111     if ( (epsilon >= 1.500) && (epsilon < 1.950) ) num_lin = 3;
1112     if ( (epsilon >= 1.950) && (epsilon < 2.800) ) num_lin = 4;
1113     if ( (epsilon >= 2.800) && (epsilon < 4.500) ) num_lin = 5;
1114     if ( (epsilon >= 4.500) && (epsilon < 6.200) ) num_lin = 6;
1115     if ( (epsilon >= 6.200) && (epsilon < 14.00) ) num_lin = 7;
1116    
1117     for (i=0;i<5;i++)
1118     for (j=0;j<4;j++)
1119     {
1120     x[i][j] = *(coeff_perez + 20*num_lin + 4*i +j);
1121     /* printf("x %d %d vaut %f\n",i,j,x[i][j]); */
1122     }
1123    
1124    
1125     if (num_lin)
1126     {
1127     for (i=0;i<5;i++)
1128     *(c_perez+i) = x[i][0] + x[i][1]*Z + Delta * (x[i][2] + x[i][3]*Z);
1129    
1130     }
1131     else
1132     {
1133     *(c_perez+0) = x[0][0] + x[0][1]*Z + Delta * (x[0][2] + x[0][3]*Z);
1134     *(c_perez+1) = x[1][0] + x[1][1]*Z + Delta * (x[1][2] + x[1][3]*Z);
1135     *(c_perez+4) = x[4][0] + x[4][1]*Z + Delta * (x[4][2] + x[4][3]*Z);
1136     *(c_perez+2) = exp( pow(Delta*(x[2][0]+x[2][1]*Z),x[2][2])) - x[2][3];
1137     *(c_perez+3) = -exp( Delta*(x[3][0]+x[3][1]*Z) )+x[3][2]+Delta*x[3][3];
1138    
1139    
1140     }
1141    
1142    
1143     return;
1144     }
1145    
1146    
1147     /* degrees into radians */
1148     double radians(double degres)
1149     {
1150     return degres*M_PI/180.0;
1151     }
1152    
1153     /* radian into degrees */
1154     double degres(double radians)
1155     {
1156     return radians/M_PI*180.0;
1157     }
1158    
1159     /* calculation of the angles dzeta and gamma */
1160     void theta_phi_to_dzeta_gamma(double theta,double phi,double *dzeta,double *gamma, double Z)
1161     {
1162     *dzeta = theta; /* dzeta = phi */
1163     if ( (cos(Z)*cos(theta)+sin(Z)*sin(theta)*cos(phi)) > 1 && (cos(Z)*cos(theta)+sin(Z)*sin(theta)*cos(phi) < 1.1 ) )
1164     *gamma = 0;
1165     else if ( (cos(Z)*cos(theta)+sin(Z)*sin(theta)*cos(phi)) > 1.1 )
1166     {
1167     printf("error in calculation of gamma (angle between point and sun");
1168     exit(3);
1169     }
1170     else
1171     *gamma = acos(cos(Z)*cos(theta)+sin(Z)*sin(theta)*cos(phi));
1172     }
1173    
1174    
1175     /********************************************************************************/
1176     /* Fonction: theta_ordered */
1177     /* */
1178     /* In: char *filename */
1179     /* */
1180     /* Out: float * */
1181     /* */
1182     /* Update: 29/08/93 */
1183     /* */
1184     /* Rem: theta en degres */
1185     /* */
1186     /* But: fournit les valeurs de theta du fichier d'entree a la memoire */
1187     /* */
1188     /********************************************************************************/
1189     float *theta_ordered(char *filename)
1190     {
1191     int i;
1192     float buffer,*ptr;
1193     FILE *file_in;
1194    
1195     if ( (file_in = frlibopen(filename)) == NULL )
1196     {
1197     fprintf(stderr,"Cannot open file %s in function theta_ordered\n",filename);
1198     exit(1);
1199     }
1200 greg 2.2
1201     skip_comments(file_in);
1202 greg 2.1
1203     if ( (ptr = malloc(145*sizeof(float))) == NULL )
1204     {
1205     fprintf(stderr,"Out of memory in function theta_ordered\n");
1206     exit(1);
1207     }
1208    
1209     for (i=0;i<145;i++)
1210     {
1211     fscanf(file_in,"%f",&buffer);
1212     *(ptr+i) = buffer;
1213     fscanf(file_in,"%f",&buffer);
1214     }
1215    
1216     fclose(file_in);
1217     return ptr;
1218     }
1219    
1220    
1221     /********************************************************************************/
1222     /* Fonction: phi_ordered */
1223     /* */
1224     /* In: char *filename */
1225     /* */
1226     /* Out: float * */
1227     /* */
1228     /* Update: 29/08/93 */
1229     /* */
1230     /* Rem: valeurs de Phi en DEGRES */
1231     /* */
1232     /* But: mettre les angles contenus dans le fichier d'entree dans la memoire */
1233     /* */
1234     /********************************************************************************/
1235     float *phi_ordered(char *filename)
1236     {
1237     int i;
1238     float buffer,*ptr;
1239     FILE *file_in;
1240    
1241     if ( (file_in = frlibopen(filename)) == NULL )
1242     {
1243     fprintf(stderr,"Cannot open file %s in function phi_ordered\n",filename);
1244     exit(1);
1245     }
1246 greg 2.2
1247     skip_comments(file_in);
1248 greg 2.1
1249     if ( (ptr = malloc(145*sizeof(float))) == NULL )
1250     {
1251     fprintf(stderr,"Out of memory in function phi_ordered");
1252     exit(1);
1253     }
1254    
1255     for (i=0;i<145;i++)
1256     {
1257     fscanf(file_in,"%f",&buffer);
1258     fscanf(file_in,"%f",&buffer);
1259     *(ptr+i) = buffer;
1260     }
1261    
1262     fclose(file_in);
1263     return ptr;
1264     }
1265    
1266    
1267     /********************************************************************************/
1268     /* Fonction: integ_lv */
1269     /* */
1270     /* In: float *lv,*theta */
1271     /* int sun_pos */
1272     /* */
1273     /* Out: double */
1274     /* */
1275     /* Update: 29/08/93 */
1276     /* */
1277     /* Rem: */
1278     /* */
1279     /* But: calcul l'integrale de luminance relative sans la dir. du soleil */
1280     /* */
1281     /********************************************************************************/
1282     double integ_lv(float *lv,float *theta)
1283     {
1284     int i;
1285     double buffer=0.0;
1286    
1287     for (i=0;i<145;i++)
1288     buffer += (*(lv+i))*cos(radians(*(theta+i)));
1289    
1290     return buffer*2*M_PI/144;
1291    
1292     }
1293    
1294    
1295    
1296    
1297    
1298    
1299     /* enter day number(double), return E0 = square(R0/R): eccentricity correction factor */
1300    
1301     double get_eccentricity()
1302     {
1303     double day_angle;
1304     double E0;
1305    
1306     day_angle = 2*M_PI*(daynumber - 1)/365;
1307     E0 = 1.00011+0.034221*cos(day_angle)+0.00128*sin(day_angle)+
1308     0.000719*cos(2*day_angle)+0.000077*sin(2*day_angle);
1309    
1310     return (E0);
1311    
1312     }
1313    
1314    
1315     /* enter sunzenith angle (degrees) return relative air mass (double) */
1316     double air_mass()
1317     {
1318     double m;
1319    
1320     if (sunzenith>90)
1321     {
1322     fprintf(stderr, "solar zenith angle larger than 90� in fuction air_mass():\n the models used are not more valid\n");
1323     exit(1);
1324     }
1325    
1326     m = 1/( cos(sunzenith*M_PI/180)+0.15*exp( log(93.885-sunzenith)*(-1.253) ) );
1327     return(m);
1328     }
1329    
1330    
1331     double get_angle_sun_direction(double sun_zenith, double sun_azimut, double direction_zenith, double direction_azimut)
1332    
1333     {
1334    
1335     double angle;
1336    
1337    
1338     if (sun_zenith == 0)
1339     puts("WARNING: zenith_angle = 0 in function get_angle_sun_vert_plan");
1340    
1341     angle = acos( cos(sun_zenith*M_PI/180)*cos(direction_zenith*M_PI/180) + sin(sun_zenith*M_PI/180)*sin(direction_zenith*M_PI/180)*cos((sun_azimut-direction_azimut)*M_PI/180) );
1342     angle = angle*180/M_PI;
1343     return(angle);
1344     }
1345    
1346    
1347    
1348    
1349    
1350    
1351    
1352