--- ray/src/px/falsecolor.csh	1991/05/23 14:22:00	1.2
+++ ray/src/px/falsecolor.csh	1991/05/23 16:41:38	1.3
@@ -8,6 +8,7 @@ onintr quit
 set mult=470
 set label=Nits
 set scale=1000
+set decades=0
 set redv='2*v-1'
 set grnv='if(v-.5,2-2*v,2*v)'
 set bluv='1-2*v'
@@ -28,6 +29,10 @@ while ($#argv > 0)
 		shift argv
 		set label="$argv[1]"
 		breaksw
+	case -log:
+		shift argv
+		set decades=$argv[1]
+		breaksw
 	case -r:
 		shift argv
 		set redv="$argv[1]"
@@ -65,7 +70,7 @@ while ($#argv > 0)
 		set ndivs="$argv[1]"
 		breaksw
 	default:
-		echo bad option "'$argv[1]'"
+		echo bad option "'$argv[1]'" >/dev/tty
 		exit 1
 	endsw
 	shift argv
@@ -83,15 +88,16 @@ btwn(a,b) : if(a-x,-1,b-x);
 frac(x) : x - floor(x);
 boundary(a,b) : neq(floor(ndivs*a),floor(ndivs*b));
 
-red=$redv;
-grn=$grnv;
-blu=$bluv;
+map(x) = x;
+red = $redv;
+grn = $grnv;
+blu = $bluv;
 
-v = li(1)*(mult/scale);
-vleft = li(1,-1,0)*(mult/scale);
-vright = li(1,1,0)*(mult/scale);
-vabove = li(1,0,1)*(mult/scale);
-vbelow = li(1,0,-1)*(mult/scale);
+v = map(li(1)*(mult/scale));
+vleft = map(li(1,-1,0)*(mult/scale));
+vright = map(li(1,1,0)*(mult/scale));
+vabove = map(li(1,0,1)*(mult/scale));
+vbelow = map(li(1,0,-1)*(mult/scale));
 isconta = or(boundary(vleft,vright),boundary(vabove,vbelow));
 iscontb = if(btwn(0,v,1),btwn(.4,frac(ndivs*v),.6),0); 
 
@@ -114,11 +120,19 @@ if ("$cpict" == "") then
 else if ("$cpict" == "$picture") then
 	set cpict=
 endif
+if ($decades > 0) then
+	set pcargs=($pcargs -e "map(x)=log10(x)/$decades+1")
+	set imap="imap(y)=10^((y-1)*$decades)"
+else
+	set imap="imap(y)=y"
+endif
 pcomb $pcargs -e 'v=(y+.5)/200;vleft=v;vright=v' \
 		-e 'vbelow=(y-.5)/200;vabove=(y+1.5)/200' \
 		-e 'ra=0;ga=0;ba=0' -x 100 -y 200 \
 		> $tempdir/scol.pic
-(echo $label; cnt $ndivs |rcalc -e '$1='"($scale)/$ndivs*($ndivs"'-.5-$1)') \
+( echo $label; cnt $ndivs \
+		| rcalc -e '$1='"($scale)*imap(($ndivs-.5-"'$1'")/$ndivs)" \
+		-e "$imap" ) \
 	| psign -cf 1 1 1 -cb 0 0 0 -h `ev "floor(2*200/$ndivs+.5)"` \
 	| pfilt -1 -x /2 -y /2 > $tempdir/slab.pic
 pcomb $pcargs $picture $cpict \