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| author | wkj <devnull@localhost> | 2004-04-21 02:16:43 +0000 |
|---|---|---|
| committer | wkj <devnull@localhost> | 2004-04-21 02:16:43 +0000 |
| commit | cd5bae7871bc0f0bc68b4d2a84703929a7a3c9d1 (patch) | |
| tree | 336db54785d2b77113a6e570574be715c7eb7d1d /src/cmd/astro/venus.c | |
| parent | 95f57b01e21feb457e79eaf52d593422c318024f (diff) | |
| download | plan9port-cd5bae7871bc0f0bc68b4d2a84703929a7a3c9d1.tar.gz plan9port-cd5bae7871bc0f0bc68b4d2a84703929a7a3c9d1.zip | |
Astro with some minor changes to placate Unix.
Diffstat (limited to 'src/cmd/astro/venus.c')
| -rw-r--r-- | src/cmd/astro/venus.c | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/src/cmd/astro/venus.c b/src/cmd/astro/venus.c new file mode 100644 index 00000000..7ee1146d --- /dev/null +++ b/src/cmd/astro/venus.c @@ -0,0 +1,126 @@ +#include "astro.h" + + +void +venus(void) +{ + double pturbl, pturbb, pturbr; + double lograd; + double dele, enom, vnom, nd, sl; + double v0, t0, m0, j0, s0; + double lsun, elong, ci, dlong; + +/* + * here are the mean orbital elements + */ + + ecc = .00682069 - .00004774*capt + 0.091e-6*capt2; + incl = 3.393631 + .0010058*capt - 0.97e-6*capt2; + node = 75.779647 + .89985*capt + .00041*capt2; + argp = 130.163833 + 1.408036*capt - .0009763*capt2; + mrad = .7233316; + anom = 212.603219 + 1.6021301540*eday + .00128605*capt2; + motion = 1.6021687039; + +/* + * mean anomalies of perturbing planets + */ + + v0 = 212.60 + 1.602130154*eday; + t0 = 358.63 + .985608747*eday; + m0 = 319.74 + 0.524032490*eday; + j0 = 225.43 + .083090842*eday; + s0 = 175.8 + .033459258*eday; + + v0 *= radian; + t0 *= radian; + m0 *= radian; + j0 *= radian; + s0 *= radian; + + incl *= radian; + node *= radian; + argp *= radian; + anom = fmod(anom, 360.)*radian; + +/* + * computation of long period terms affecting the mean anomaly + */ + + anom += + (2.761-0.022*capt)*radsec*sin( + 13.*t0 - 8.*v0 + 43.83*radian + 4.52*radian*capt) + + 0.268*radsec*cos(4.*m0 - 7.*t0 + 3.*v0) + + 0.019*radsec*sin(4.*m0 - 7.*t0 + 3.*v0) + - 0.208*radsec*sin(s0 + 1.4*radian*capt); + +/* + * computation of elliptic orbit + */ + + enom = anom + ecc*sin(anom); + do { + dele = (anom - enom + ecc * sin(enom)) / + (1 - ecc*cos(enom)); + enom += dele; + } while(fabs(dele) > converge); + vnom = 2*atan2(sqrt((1+ecc)/(1-ecc))*sin(enom/2), + cos(enom/2)); + rad = mrad*(1 - ecc*cos(enom)); + + lambda = vnom + argp; + +/* + * perturbations in longitude + */ + + icosadd(venfp, vencp); + pturbl = cosadd(4, v0, t0, m0, j0); + pturbl *= radsec; + +/* + * perturbations in latidude + */ + + pturbb = cosadd(3, v0, t0, j0); + pturbb *= radsec; + +/* + * perturbations in log radius vector + */ + + pturbr = cosadd(4, v0, t0, m0, j0); + +/* + * reduction to the ecliptic + */ + + lambda += pturbl; + nd = lambda - node; + lambda = node + atan2(sin(nd)*cos(incl),cos(nd)); + + sl = sin(incl)*sin(nd); + beta = atan2(sl, pyth(sl)) + pturbb; + + lograd = pturbr*2.30258509; + rad *= 1 + lograd; + + + motion *= radian*mrad*mrad/(rad*rad); + +/* + * computation of magnitude + */ + + lsun = 99.696678 + 0.9856473354*eday; + lsun *= radian; + elong = lambda - lsun; + ci = (rad - cos(elong))/sqrt(1 + rad*rad - 2*rad*cos(elong)); + dlong = atan2(pyth(ci), ci)/radian; + mag = -4 + .01322*dlong + .0000004247*dlong*dlong*dlong; + + semi = 8.41; + + helio(); + geo(); +} |
