added Steve's (K9AN) new versions

[spider.git] / perl / Sun.pm

diff --git a/perl/Sun.pm b/perl/Sun.pm
index 13f7d20cdc1bc7cb60cca01cae1466bfd20bf144..2fe033cd8e42911c37209f430120f402312dea98 100644 (file)
--- a/perl/Sun.pm
+++ b/perl/Sun.pm
@@ -18,6 +18,8 @@
 #
 # $Id$
 # 
+# 2001/09/15 some changes to take care of cases where the object 
+#            doesn't rise or set on a given day... 
 
 package Sun;
 
@@ -160,6 +162,10 @@ sub rise_set
        my $lon = shift;
        my $sun0_moon1=shift;           # 0 for sun, 1 for moon, 2 for venus...
 
+       my $norise = 0;
+       my $noset = 0;
+       my ($risehr,$risemin,$risetime,$sethr,$setmin,$settime);
+
        my ($alpha1,$alpha2,$alpha3,$delta1,$delta2,$delta3);
        my ($m0,$m1,$m2,$theta,$alpha,$delta,$H,$az,$h,$h0,$aznow,$hnow,$corr);
        my ($i,$arg,$argtest,$H0,$alphanow,$deltanow,$distance,$distancenow);
@@ -205,14 +211,10 @@ sub rise_set
        }
 
        $arg = (sindeg($h0)-sindeg($lat)*sindeg($delta2))/(cosdeg($lat)*cosdeg($delta2));
-       $argtest = tandeg($lat)*tandeg($delta2);
-
-       if ( $argtest < -1. ) {
-               return sprintf("Doesn't rise.");
-       }
-       if ( $argtest > 1. ) {
-               return sprintf("Doesn't set.");
-       }
+       if ( abs($arg) > 1. ) {    # either up all day or down all day 
+               $norise = 1;       # leave it to the user to examine 
+               $noset = 1;        # the elevation angle (or look outside!) 
+       }                          # to figure out which.
 
        $H0 = acos($arg)*$r2d;
        my $aa=$alpha2-$alpha1;
@@ -248,56 +250,71 @@ sub rise_set
                $m0=$m0-1 if( $m0 > 1 );
        }
 
-       $m1 = $m0 - $H0/360.;
-       $m1=$m1+1 if( $m1 < 0 );
-       $m1=$m1-1 if( $m1 > 1 );
-       for ($i=1; $i<=2; $i++) {
-               $theta = $theta0+360.985647*$m1;
-               $alpha=$alpha2+$m1*($aa+$ba+$m1*$ca)/2;
-               $delta=$delta2+$m1*($ad+$bd+$m1*$cd)/2;
-               $H=$theta-$lon-$alpha;
-               $H=reduce_angle_to_360($H);
-               ($az,$h)=get_az_el($H,$delta,$lat);
-               $corr=($h-$h0)/(360*(cosdeg($delta)*cosdeg($lat)*sindeg($H)));
-               $m1=$m1+$corr;
+
+       if( !$norise ){
+               $m1 = $m0 - $H0/360.;
                $m1=$m1+1 if( $m1 < 0 );
                $m1=$m1-1 if( $m1 > 1 );
+               for ($i=1; $i<=2; $i++) {
+                       $theta = $theta0+360.985647*$m1;
+                       $alpha=$alpha2+$m1*($aa+$ba+$m1*$ca)/2;
+                       $delta=$delta2+$m1*($ad+$bd+$m1*$cd)/2;
+                       $H=$theta-$lon-$alpha;
+                       $H=reduce_angle_to_360($H);
+                       ($az,$h)=get_az_el($H,$delta,$lat);
+                       $corr=($h-$h0)/(360*(cosdeg($delta)*cosdeg($lat)*sindeg($H)));
+                       $m1=$m1+$corr;
+                       $norise=1 if( $m1 < 0 || $m1 > 1); 
+               }
        }
 
-       $m2 = $m0 + $H0/360.;
-       $m2=$m2+1 if( $m2 < 0 );
-       $m2=$m2-1 if( $m2 > 1 );
-       for ($i=1; $i<=2; $i++) {
-               $theta = $theta0+360.985647*$m2;
-               $alpha=$alpha2+$m2*($aa+$ba+$m2*$ca)/2;
-               $delta=$delta2+$m2*($ad+$bd+$m2*$cd)/2;
-               $H=$theta-$lon-$alpha;
-               $H=reduce_angle_to_360($H);
-               ($az,$h)=get_az_el($H,$delta,$lat);
-               $corr=($h-$h0)/(360*(cosdeg($delta)*cosdeg($lat)*sindeg($H)));
-               $m2 = $m2 + $corr;
+       if( !$norise ) {
+               $risehr=int($m1*24);
+               $risemin=($m1*24-int($m1*24))*60+0.5;
+               if ( $risemin >= 60 ) {
+                       $risemin=$risemin-60;
+                       $risehr=$risehr+1;
+               }
+               $risetime=sprintf("%02d:%02dZ",$risehr,$risemin);
+       } else {
+               $risetime="NoRise";
+       }
+
+       if( !$noset ){
+               $m2 = $m0 + $H0/360.;
                $m2=$m2+1 if( $m2 < 0 );
                $m2=$m2-1 if( $m2 > 1 );
+               for ($i=1; $i<=2; $i++) {
+                       $theta = $theta0+360.985647*$m2;
+                       $alpha=$alpha2+$m2*($aa+$ba+$m2*$ca)/2;
+                       $delta=$delta2+$m2*($ad+$bd+$m2*$cd)/2;
+                       $H=$theta-$lon-$alpha;
+                       $H=reduce_angle_to_360($H);
+                       ($az,$h)=get_az_el($H,$delta,$lat);
+                       $corr=($h-$h0)/(360*(cosdeg($delta)*cosdeg($lat)*sindeg($H)));
+                       $m2 = $m2 + $corr;
+                       $noset=1 if( $m2 < 0 || $m2 > 1); 
+               }
        }
-       my ($risehr,$risemin,$sethr,$setmin);
-       $risehr=int($m1*24);
-       $risemin=($m1*24-int($m1*24))*60+0.5;
-       if ( $risemin >= 60 ) {
-               $risemin=$risemin-60;
-               $risehr=$risehr+1;
-       }
-       $sethr=int($m2*24);
-       $setmin=($m2*24-int($m2*24))*60+0.5;
-       if ( $setmin >= 60 ) {
-               $setmin=$setmin-60;
-               $sethr=$sethr+1;
-       }
+
+       if( !$noset ) {
+               $sethr=int($m2*24);
+               $setmin=($m2*24-int($m2*24))*60+0.5;
+               if ( $setmin >= 60 ) {
+                       $setmin=$setmin-60;
+                       $sethr=$sethr+1;
+               }
+               $settime=sprintf("%02d:%02dZ",$sethr,$setmin);
+       } else {
+               $settime="NoSet ";
+       }                       
+
 
        if ( $sun0_moon1 == 0 ) {
-               return (sprintf("%02d:%02dZ", $risehr,$risemin), sprintf("%02d:%02dZ",$sethr,$setmin),$aznow+180,$hnow);
+               return (sprintf("%s", $risetime), sprintf("%s",$settime),$aznow+180,$hnow);
        }
        if ( $sun0_moon1 == 1 ) {
-               return (sprintf("%02d:%02dZ", $risehr,$risemin), sprintf("%02d:%02dZ",$sethr,$setmin), 
+               return (sprintf("%s", $risetime), sprintf("%s",$settime), 
                                $aznow+180,$hnow, -40*log10($distance/385000) );
        }
 }