1 #include "config.h"
2
3 /* Copyright (C) 2002 Brad Jorsch <anomie@users.sourceforge.net>
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20 #include <math.h>
21 #if TM_IN_SYS_TIME
22 # if TIME_WITH_SYS_TIME
23 # include <sys/time.h>
24 # include <time.h>
25 # else
26 # if HAVE_SYS_TIME_H
27 # include <sys/time.h>
28 # else
29 # include <time.h>
30 # endif
31 # endif
32 #else
33 #include <time.h>
34 #endif
35 #include <ctype.h>
36 #include <string.h>
37 #include <stdlib.h>
38 #include "convert.h"
39
40 /*
41 * To indicate unavailable data
42 * 999 is used for temperature
43 * x<0 is used for rh, pressure, and windspeed
44 */
45
46
47 /* Calculations */
48
rh_C(int temp_C,int dewpt_C)49 int rh_C(int temp_C, int dewpt_C){
50 float f;
51
52 if(temp_C==999 || dewpt_C==999) return 999;
53
54 f=1782.75*(dewpt_C-temp_C)/((237.7+dewpt_C)*(237.7+temp_C));
55 return round(pow(10, f+2));
56 }
57
rh_F(int temp_F,int dewpt_F)58 int rh_F(int temp_F, int dewpt_F){
59 float f;
60
61 if(temp_F==999 || dewpt_F==999) return 999;
62
63 f=3208.95*(dewpt_F-temp_F)/((395.86+dewpt_F)*(395.86+temp_F));
64 return round(pow(10, f+2));
65 }
66
heatindex_C(int temp_C,int rh)67 int heatindex_C(int temp_C, int rh){
68 #if 1
69 if(temp_C==999 || temp_C<21 || rh<0) return 999;
70 return heatindex_F(temp_C2F(temp_C), rh);
71 #else
72 int temp2, rh2;
73
74 if(temp_C==999 || temp_C<38 || rh<0) return 999;
75
76 temp2=temp_C*temp_C;
77 rh2=rh*rh;
78 return round(16.18754948 + 2.900509394*temp_C - 0.0221545692*temp2 + 4.20938791*rh - 0.26300889*temp_C*rh + 0.0039811176*temp2*rh - 0.02956469*rh2 + 0.001305828*temp_C*rh2 - 6.4476e-06*temp2*rh2);
79 #endif
80 }
81
heatindex_F(int temp_F,int rh)82 int heatindex_F(int temp_F, int rh){
83 int temp2, temp3, rh2, rh3;
84
85 if(temp_F==999 || temp_F<70 || rh<0) return 999;
86
87 temp2=temp_F*temp_F;
88 temp3=temp2*temp_F;
89 rh2=rh*rh;
90 rh3=rh2*rh;
91 return round(16.923 + .185212*temp_F + 5.37941*rh - .100254*temp_F*rh + (9.41695e-3)*temp2 + (7.28898e-3)*rh2 + (3.45372e-4)*temp2*rh - (8.14971e-4)*temp_F*rh2 + (1.02102e-5)*temp2*rh2 - (3.8646e-5)*temp3 + (2.91583e-5)*rh3 + (1.42721e-6)*temp3*rh + (1.97483e-7)*temp_F*rh3 - (2.18429e-8)*temp3*rh2 + (8.43296e-10)*temp2*rh3 - (4.81975e-11)*temp3*rh3);
92 #if 0
93 return round(-42.379 + 2.04901523*temp_F + 10.14333127*rh - 0.22475541*temp_F*rh - .00683783*temp2 - .05481717*rh2 + .00122874*temp2*rh + .00085282*temp_F*rh2 - .00000199*temp2*rh2);
94 #endif
95 }
96
windchill_C(int temp_C,int windspeed)97 int windchill_C(int temp_C, int windspeed){
98 if(temp_C==999 || windspeed<0) return 999;
99
100 return windchill_F(temp_C2F(temp_C), windspeed);
101 }
102
windchill_F(int temp_F,int windspeed)103 int windchill_F(int temp_F, int windspeed){
104 double ret;
105 if(temp_F==999 || windspeed<0) return 999;
106
107 ret=35.74 + 0.6215*temp_F + (-35.75 + 0.4275*temp_F)*pow(windspeed*50292/57875.0, 0.16);
108 if(ret>temp_F) return temp_F;
109 return round(ret);
110 }
111
112 /* Length Conversions */
113
in2cm(int in)114 int in2cm(int in){
115 if(in<0) return in;
116 return round(in*2.54);
117 }
118
m2mi(int meters)119 float m2mi(int meters){
120 if(meters<0) return meters;
121 return meters*125/201168;
122 }
123
124 /* Windspeed Conversions */
125
knots2mph(int knots)126 int knots2mph(int knots){
127 if(knots<0) return knots;
128 return round(knots*57875/50292.0);
129 }
130
knots2kph(int knots)131 int knots2kph(int knots){
132 if(knots<0) return knots;
133 return round(knots*463/250.0);
134 }
135
kph2knots(int kph)136 int kph2knots(int kph){
137 if(kph<0) return kph;
138 return round(kph*250/463.0);
139 }
140
knots2mps(int knots)141 int knots2mps(int knots){
142 if(knots<0) return knots;
143 return round(knots*463/900.0);
144 }
145
mps2knots(int mps)146 int mps2knots(int mps){
147 if(mps<0) return mps;
148 return round(mps*900/463.0);
149 }
150
knots2beaufort(int knots)151 int knots2beaufort(int knots){
152 if(knots<0) return knots;
153 if(knots<1) return 0;
154 if(knots<=3) return 1;
155 if(knots<=6) return 2;
156 if(knots<=10) return 3;
157 if(knots<=16) return 4;
158 if(knots<=21) return 5;
159 if(knots<=27) return 6;
160 if(knots<=33) return 7;
161 if(knots<=40) return 8;
162 if(knots<=47) return 9;
163 if(knots<=55) return 10;
164 if(knots<=63) return 11;
165 return 12;
166 }
167
168
169 /* Temperature Conversions */
170
temp_C2F(int temp_C)171 int temp_C2F(int temp_C){
172 if(temp_C==999) return 999;
173 return round(temp_C*9/5.0+32);
174 }
175
temp_F2C(int temp_F)176 int temp_F2C(int temp_F){
177 if(temp_F==999) return 999;
178 return round((temp_F-32)*5/9.0);
179 }
180
181
182 /* Pressure Conversions */
183
inHg2mmHg(float inHg)184 float inHg2mmHg(float inHg){
185 if(inHg<0) return inHg;
186 return inHg*25.4;
187 }
188
inHg2hPa(float inHg)189 float inHg2hPa(float inHg){
190 if(inHg<0) return inHg;
191 return inHg*33.8639;
192 }
193
inHg2atm(float inHg)194 float inHg2atm(float inHg){
195 if(inHg<0) return inHg;
196 return inHg*.033421052632;
197 }
198
hPa2inHg(float hPa)199 float hPa2inHg(float hPa){
200 if(hPa<0) return hPa;
201 return hPa/33.8639;
202 }
203
204
205 /* Time Conversions */
206
207 /* NOTE: y%400==100 because y=year-1900 */
208 #define is_leap(y) (y%4==0 && (y%100!=0 || y%400==100))
209
210 /* mktime for UTC, more or less.
211 * Differences:
212 * - no range checking
213 * - never recalculates tm_wday or tm_yday
214 */
mkgmtime(struct tm * tm)215 time_t mkgmtime(struct tm *tm){
216 static long msec[]={0, 2678400, 5097600, 7776000, 10368000, 13046400, 15638400, 18316800, 20995200, 23587200, 26265600, 28857600};
217 time_t t;
218 int i;
219
220 while(tm->tm_mon>=12){
221 tm->tm_year++;
222 tm->tm_mon-=12;
223 }
224 while(tm->tm_mon<0){
225 tm->tm_year--;
226 tm->tm_mon+=12;
227 }
228
229 t=0;
230 if(tm->tm_year>70){
231 for(i=70; i<tm->tm_year; i++){
232 t+=31536000;
233 if(is_leap(i)) t+=86400;
234 }
235 } else if(tm->tm_year<70){
236 for(i=69; i>=tm->tm_year; i--){
237 t-=31536000;
238 if(is_leap(i)) t-=86400;
239 }
240 }
241 t+=msec[tm->tm_mon];
242 if(tm->tm_mon>1 && is_leap(tm->tm_year)) t+=86400;
243 t+=(((tm->tm_mday-1)*24+tm->tm_hour)*60+tm->tm_min)*60+tm->tm_sec;
244
245 return t;
246 }
247
utc2local(int hm,int * month,int * day,int * year,int * wday)248 int utc2local(int hm, int *month, int *day, int *year, int *wday){
249 time_t t=time(NULL);
250 struct tm *tm;
251
252 tm=gmtime(&t);
253 tm->tm_hour=hm/100;
254 tm->tm_min=hm%100;
255 if(month!=NULL && *month!=-1) tm->tm_mon=*month-1;
256 if(day!=NULL && *day!=-1) tm->tm_mday=*day;
257 if(year!=NULL && *year!=-1) tm->tm_year=*year;
258
259 t=mkgmtime(tm);
260 tm=localtime(&t);
261
262 if(month!=NULL) *month=tm->tm_mon+1;
263 if(day!=NULL) *day=tm->tm_mday;
264 if(year!=NULL) *year=tm->tm_year;
265 if(wday!=NULL) *wday=tm->tm_wday;
266 return tm->tm_hour*100+tm->tm_min;
267 }
268
local2utc(int hm,int * month,int * day,int * year,int * wday)269 int local2utc(int hm, int *month, int *day, int *year, int *wday){
270 time_t t=time(NULL);
271 struct tm *tm;
272
273 tm=localtime(&t);
274 tm->tm_hour=hm/100;
275 tm->tm_min=hm%100;
276 if(month!=NULL && *month!=-1) tm->tm_mon=*month-1;
277 if(day!=NULL && *day!=-1) tm->tm_mday=*day;
278 if(year!=NULL && *year!=-1) tm->tm_year=*year;
279
280 t=mktime(tm);
281 tm=gmtime(&t);
282
283 if(month!=NULL) *month=tm->tm_mon+1;
284 if(day!=NULL) *day=tm->tm_mday;
285 if(year!=NULL) *year=tm->tm_year;
286 if(wday!=NULL) *wday=tm->tm_wday;
287 return tm->tm_hour*100+tm->tm_min;
288 }
289
fix_date(int * month,int * day,int * year,int * wday)290 void fix_date(int *month, int *day, int *year, int *wday){
291 time_t t=time(NULL);
292 struct tm *tm;
293
294 tm=gmtime(&t);
295 if(month!=NULL && *month!=-1) tm->tm_mon=*month-1;
296 if(day!=NULL && *day!=-1) tm->tm_mday=*day;
297 if(year!=NULL && *year!=-1) tm->tm_year=*year;
298
299 t=mkgmtime(tm);
300 tm=gmtime(&t);
301
302 if(month!=NULL) *month=tm->tm_mon+1;
303 if(day!=NULL) *day=tm->tm_mday;
304 if(year!=NULL) *year=tm->tm_year;
305 if(wday!=NULL) *wday=tm->tm_wday;
306 }
307
hm2min(int hm)308 int hm2min(int hm){
309 return hm/100*60+hm%100;
310 }
311
312 /* Letter Case (destructive!) */
313
str_upper(char * str)314 char *str_upper(char *str){
315 char *c;
316
317 for(c=str; *c!='\0'; c++){
318 *c=toupper(*c);
319 }
320 return str;
321 }
322
str_lower(char * str)323 char *str_lower(char *str){
324 char *c;
325
326 for(c=str; *c!='\0'; c++){
327 *c=tolower(*c);
328 }
329 return str;
330 }
331
332
333 /* Angle conversions */
334
335 /* Convert radian angle to degrees */
rad2deg(double angle)336 double rad2deg(double angle) {
337 return 180.0*angle/PI;
338 }
339
340 /* Convert degree angle to radians */
deg2rad(double angle)341 double deg2rad(double angle) {
342 return PI*angle/180.0;
343 }
344
345
346 /* Date conversions */
347
348 /* Numerical day-of-year from month, day and year */
mdy2doy(int mn,int dy,int y)349 int mdy2doy(int mn, int dy, int y) {
350 return 275*mn/9 - ((y%4==0 && (y%100!=0 || y%400==100))?1:2)*(mn + 9)/12 + dy-30;
351 }
352
353 /* Julian day from month/day/year */
mdy2jd(int year,int month,int day)354 double mdy2jd(int year, int month, int day) {
355 int A, B;
356
357 year+=1900;
358 if (month <= 2) {
359 year -= 1;
360 month += 12;
361 }
362 A=year/100;
363 B=2 - A + A/4;
364
365 return (int)(365.25*(year + 4716)) + (int)(30.6001*(month+1)) + day + B - 1524.5;
366 }
367
368 /* convert Julian Day to centuries since J2000.0. */
jd2jcent(double jd)369 double jd2jcent(double jd) {
370 return (jd - 2451545.0)/36525.0;
371 }
372
373 /* convert centuries since J2000.0 to Julian Day. */
jcent2jd(double t)374 double jcent2jd(double t) {
375 return t * 36525.0 + 2451545.0;
376 }
377
378
379 /* Lat/Long conversions */
380
parse_dd_or_dms(char * s,char ** e)381 static double parse_dd_or_dms(char *s, char **e){
382 double deg;
383
384 *e=s;
385 if(strchr(s, 'x') || strchr(s, 'X')) return NAN;
386 if(!strchr(s, '\'')){
387 if(!isdigit(*s) && *s!='.') return NAN;
388 return strtod(s, e);
389 }
390
391 if(!isdigit(*s)) return NAN;
392 deg=strtol(s, e, 10);
393 if(*e==s || *e==NULL || **e!='\'') return deg;
394 s=++(*e);
395 if(!isdigit(*s)) return deg;
396 deg+=strtol(s, e, 10)/60.0;
397 if(*e==s || *e==NULL || **e!='\'') return deg;
398 s=++(*e);
399 if(!isdigit(*s) && *s!='.') return NAN;
400 deg+=strtod(s, e)/3600.0;
401 if(*e!=s && *e!=NULL && **e=='\'') (*e)++;
402 return deg;
403 }
404
str2dd(char * s,double * lat,double * lon)405 int str2dd(char *s, double *lat, double *lon){
406 char *e;
407 int dir=0;
408 char c;
409
410 c=toupper(*s);
411 if(c=='+' || c=='N'){
412 s++; dir=1;
413 }
414 if(c=='-' || c=='S'){
415 s++; dir=-1;
416 }
417
418 *lat=parse_dd_or_dms(s, &e);
419 if(isnan(*lat) || e==NULL || e==s || *e=='\0') return 0;
420 if(!dir){
421 c=toupper(*e);
422 if(c=='N') dir=1;
423 if(c=='S') dir=-1;
424 if(dir) e++;
425 }
426 if(dir<0) *lat=-*lat;
427
428 while(isspace(*e)) e++;
429 if(*e=='\0') return 0;
430
431 s=e; dir=0;
432 c=toupper(*s);
433 if(c=='+' || c=='W'){
434 s++; dir=1;
435 }
436 if(c=='-' || c=='E'){
437 s++; dir=-1;
438 }
439
440 *lon=parse_dd_or_dms(s, &e);
441 if(isnan(*lon) || e==s) return 0;
442 if(e==NULL || *e=='\0') return 1;
443 if(dir==0){
444 c=toupper(*e);
445 if(c=='W') dir=1;
446 if(c=='E') dir=-1;
447 if(dir!=0) e++;
448 }
449 if(dir<0) *lon=-*lon;
450
451 return (*e=='\0');
452 }
453