这个是科学网的大牛改编的R代码。我计划将它改写为C或Matlab代码。后者简单些但是会牺牲运行效率。
### 快速日食搜索,jd为朔时间 ### 改编自许剑伟老师的《寿星万年历》javascript源代码 ### 输入儒略日2000,计算最近的朔的时间,并判断该次朔是否会发生日食。 DateSolarEclipse < - function (jd){ rad = 180*3600/pi; #每弧度的角秒数 radd = 180/pi; #每弧度的度数 pi2 = pi*2; pi_2 = pi/2; J2000 = 2451545; re=list(); W = floor((jd+8)/29.5306)*pi*2; #合朔时的日月黄经差 #合朔时间计算,2000前+-4000年误差1小时以内,+-2000年小于10分钟 t = ( W + 1.08472 )/7771.37714500204; #平朔时间 re$jd = re$jdNewMoon = t*36525; t2=t*t t3=t2*t t4=t3*t; L = ( 93.2720993+483202.0175273*t-0.0034029*t2-t3/3526000+t4/863310000 )/180*pi; re$ac=1 re$type='N'; if(abs(sin(L))>0.4) return(re); #一般大于21度已不可能 t = t - ( -0.0000331*t*t + 0.10976 *cos( 0.785 + 8328.6914*t) )/7771; t2= t*t; L = (-1.084719 +7771.377145013*t -0.0000331*t2 + (22640 * cos(0.785+ 8328.6914*t +0.000152*t2) +4586 * cos(0.19 + 7214.063*t -0.000218*t2) +2370 * cos(2.54 + 15542.754*t -0.000070*t2) + 769 * cos(3.1 + 16657.383*t) + 666 * cos(1.5 + 628.302*t) + 412 * cos(4.8 + 16866.93*t) + 212 * cos(4.1 -1114.63*t) + 205 * cos(0.2 + 6585.76*t) + 192 * cos(4.9 + 23871.45*t) + 165 * cos(2.6 + 14914.45*t) + 147 * cos(5.5 -7700.39*t) + 125 * cos(0.5 + 7771.38*t) + 109 * cos(3.9 + 8956.99*t) + 55 * cos(5.6 -1324.18*t) + 45 * cos(0.9 + 25195.62*t) + 40 * cos(3.8 -8538.24*t) + 38 * cos(4.3 + 22756.82*t) + 36 * cos(5.5 + 24986.07*t) -6893 * cos(4.669257+628.3076*t) - 72 * cos(4.6261 +1256.62*t) - 43 * cos(2.67823 +628.31*t)*t + 21) / rad); t = t + ( W - L ) / ( 7771.38 - 914 * sin( 0.7848 + 8328.691425*t + 0.0001523*t2 ) - 179 * sin( 2.543 +15542.7543*t ) - 160 * sin( 0.1874 + 7214.0629*t ) ); re$jd = re$jdNewMoon = jd = t*36525; #朔时刻 #纬 52,15 (角秒) t2=t*t/10000; t3=t2*t/10000; mB= ( 18461*cos(0.0571+ 8433.46616*t -0.640*t2 -1*t3) + 1010*cos(2.413 + 16762.1576 *t + 0.88 *t2 + 25*t3) + 1000*cos(5.440 -104.7747 *t + 2.16 *t2 + 26*t3) + 624*cos(0.915 + 7109.2881 *t + 0 *t2 + 7*t3) + 199*cos(1.82 + 15647.529 *t -2.8 *t2 -19*t3) + 167*cos(4.84 -1219.403 *t -1.5 *t2 -18*t3) + 117*cos(4.17 + 23976.220 *t -1.3 *t2 + 6*t3) + 62*cos(4.8 + 25090.849 *t + 2 *t2 + 50*t3) + 33*cos(3.3 + 15437.980 *t + 2 *t2 + 32*t3) + 32*cos(1.5 + 8223.917 *t + 4 *t2 + 51*t3) + 30*cos(1.0 + 6480.986 *t + 0 *t2 + 7*t3) + 16*cos(2.5 -9548.095 *t -3 *t2 -43*t3) + 15*cos(0.2 + 32304.912 *t + 0 *t2 + 31*t3) + 12*cos(4.0 + 7737.590 *t) + 9*cos(1.9 + 15019.227 *t) + 8*cos(5.4 + 8399.709 *t) + 8*cos(4.2 + 23347.918 *t) + 7*cos(4.9 -1847.705 *t) + 7*cos(3.8 -16133.856 *t) + 7*cos(2.7 + 14323.351 *t)); mB = mB / rad; #月地距离 106, 23 (千米) mR = (385001 +20905*cos(5.4971+ 8328.691425*t+ 1.52 *t2 + 25*t3) + 3699*cos(4.900 + 7214.06287*t -2.18 *t2 -19*t3) + 2956*cos(0.972 + 15542.75429*t -0.66 *t2 + 6*t3) + 570*cos(1.57 + 16657.3828 *t + 3.0 *t2 + 50*t3) + 246*cos(5.69 -1114.6286 *t -3.7 *t2 -44*t3) + 205*cos(1.02 + 14914.4523 *t -1 *t2 + 6*t3) + 171*cos(3.33 + 23871.4457 *t + 1 *t2 + 31*t3) + 152*cos(4.94 + 6585.761 *t -2 *t2 -19*t3) + 130*cos(0.74 -7700.389 *t -2 *t2 -25*t3) + 109*cos(5.20 + 7771.377 *t) + 105*cos(2.31 + 8956.993 *t + 1 *t2 + 25*t3) + 80*cos(5.38 -8538.241 *t + 2.8 *t2 + 26*t3) + 49*cos(6.24 + 628.302 *t) + 35*cos(2.7 + 22756.817 *t -3 *t2 -13*t3) + 31*cos(4.1 + 16171.056 *t -1 *t2 + 6*t3) + 24*cos(1.7 + 7842.365 *t -2 *t2 -19*t3) + 23*cos(3.9 + 24986.074 *t + 5 *t2 + 75*t3) + 22*cos(0.4 + 14428.126 *t -4 *t2 -38*t3) + 17*cos(2.0 + 8399.679 *t)); mR = mR/ 6378.1366; t=jd/365250; t2=t*t; t3=t2*t; #误0.0002AU sR = (10001399 #日地距离 +167070*cos(3.098464 + 6283.07585*t) + 1396*cos(3.0552 + 12566.1517 *t) + 10302*cos(1.10749 + 6283.07585*t)*t + 172*cos(1.064 + 12566.152 *t)*t + 436*cos(5.785 + 6283.076 *t)*t2 + 14*cos(4.27 + 6283.08 *t)*t3) sR = sR * 1.49597870691/6378.1366*10; #经纬速度 t=jd/36525; vL = (7771 #月日黄经差速度 -914*sin(0.785 + 8328.6914*t) -179*sin(2.543 +15542.7543*t) -160*sin(0.187 + 7214.0629*t)); vB = (-755*sin(0.057 + 8433.4662*t) #月亮黄纬速度 - 82*sin(2.413 +16762.1576*t)); vR =(-27299*sin(5.497 + 8328.691425*t) - 4184*sin(4.900 + 7214.06287*t) - 7204*sin(0.972 +15542.75429*t)); vL = vL/36525 vB = vB/36525 vR = vR/36525; #每日速度 gm = mR*sin(mB)*vL/sqrt(vB*vB+vL*vL); smR= sR-mR; #gm伽马值,smR日月距 mk = 0.2725076; sk = 109.1222; f1 = (sk+mk)/smR; r1 = mk+f1*mR; #tanf1半影锥角, r1半影半径 f2 = (sk-mk)/smR; r2 = mk-f2*mR; #tanf2本影锥角, r2本影半径 b = 0.9972; Agm = abs(gm); Ar2 = abs(r2); fh2 = mR-mk/f2; if(Agm < 1){ h = sqrt(1-gm*gm) }else{ h = 0 } ## h = Agm<1 ? sqrt(1-gm*gm) : 0; #fh2本影顶点的z坐标 ## ls1,ls2,ls3,ls4; if(fh2<h) { re$type = 'T'; #全食 }else{ re$type = 'A'; #环食 } ls1 = Agm-(b+r1 ); if(abs(ls1)<0.016) re$ac=0; #无食分界 ls2 = Agm-(b+Ar2); if(abs(ls2)<0.016) re$ac=0; #偏食分界 ls3 = Agm-(b ); if(abs(ls3)<0.016) re$ac=0; #无中心食分界 ls4 = Agm-(b-Ar2); if(abs(ls4)<0.016) re$ac=0; #有中心食分界(但本影未全部进入) if (ls1>0) { re$type = 'N'; #无日食 } else { if(ls2>0) { re$type = 'P'; #偏食 } else { if(ls3>0) { re$type = paste(re$type, '0', sep = ""); #无中心 } else { if(ls4>0) { re$type = paste(re$type, '1', sep = ""); #有中心(本影未全部进入) } else { #本影全进入 if(abs(fh2-h)<0.019) re$ac=0; if( abs(fh2) dr = vR*h/vL/mR; H1 = mR-dr-mk/f2; #入点影锥z坐标 H2 = mR+dr-mk/f2; #出点影锥z坐标 if(H1>0) re$type='H3'; #环全全 if(H2>0) re$type='H2'; #全全环 if(H1>0&H2>0) re$type='H'; #环全环 if(abs(H1)<0.019) re$ac=0; if(abs(H2)<0.019) re$ac=0; } } } } } return (re); } #取整数部分 int2 < - function (v) { return (floor(v)); } ### 公历转儒略日 JD <- function(y,m,d){ n=0;G=0; if(y*372+m*31+int2(d)>=588829) G = 1; #判断是否为格里高利历日1582*372+10*31+15 if(m< =2) { m = m +12; y = y - 1; } if(G > 0) { n=int2(y/100); n=2-n+int2(n/4); #加百年闰 } res < - int2(365.25*(y+4716)) + int2(30.6001*(m+1))+d+n - 1524.5; class(res) <- "JD" return(res) } ### 将儒略日转换为儒略日2000 JD2000 <- function(jd){ res return(res) } ### 将日期转换为儒略日2000 date2JD2000 <- function(y,m,d){ juliand res return(res) } ### 打印JD类型对象的方法 print.JD <- function(JD){ print(sprintf("%f",JD)) } ##儒略日转为公历 Julian2Date <- function(jd){ r = list(); D = int2(jd+0.5); F= jd+0.5-D #取得日数的整数部份A及小数部分F if(D >= 2299161) { c = int2((D-1867216.25)/36524.25); D = D + 1 + c - int2(c/4); } D = D + 1524; r$Y = int2((D - 122.1)/365.25);#年数 D = D - int2(365.25*r$Y); r$M = int2(D/30.601); #月数 D = D - int2(30.601*r$M); r$D = D; #日数 if(r$M>13) { r$M = r$M - 13; r$Y = r$Y - 4715; } else { r$M = r$M - 1; r$Y = r$Y - 4716; } #日的小数转为时分秒 F = F * 24; r$h=int2(F); F = F - r$h; F = F * 60; r$m=int2(F); F = F -r$m; F = F * 60; r$s=F; return(r); } #日期转为字符串 DD2str < - function(r){ Y = r$Y M = r$M D = r$D; h = r$h; m = r$m; s = int2(r$s+0.5); if(s >= 60) { s = s - 60; m = m + 1; } if(m >= 60) { m = m - 60 h = h + 1; } h = paste("0", h, sep = ""); m = paste("0", m, sep = ""); s = paste("0", s, sep = ""); Y = substr(Y, nchar(Y)- 4, nchar(Y) ); M = substr(M, nchar(M)- 1, nchar(M) ); D = substr(D, nchar(D)- 1, nchar(D) ); h = substr(h, nchar(h)- 1, nchar(h) ); m = substr(m, nchar(m)- 1, nchar(m) ); s = substr(s, nchar(s)- 1, nchar(s) ); res < - paste(Y,"-",M,"-",D," ",h,":",m,":",s, sep = ""); return(res) } JD2str <- function(jd){ #JD转为串 r = DD( jd ); res return(res) } ### 判断距离输入日期最近的朔,有没有日食发生。 ## "P"为偏食 ## "T"为全食 ## "A"为日环食 ## "N"没有日食发生 find.solar.eclipse <- function(y,m,d){ res dd date.solar.eclipse type res$NewMoonTime res$EclipseType return(res) } ##距离1987年9月23日最近的朔,以及日食类型 find.solar.eclipse(1987,9,23)
代码来自科学网
By 高达数字实验室 http://gndrive.org/
代码好长啊~~