Repatch (from linux) of OSX IRAF

1 files changed, 33 insertions, 0 deletions

diff --git a/math/llsq/g1.f b/math/llsq/g1.f
new file mode 100644
index 00000000..5d44c50b
--- /dev/null
+++ b/math/llsq/g1.f
@@ -0,0 +1,33 @@
+      subroutine g1 (a,b,cos,sin,sig)
+c     c.l.lawson and r.j.hanson, jet propulsion laboratory, 1973 jun 12
+c     to appear in 'solving least squares problems', prentice-hall, 1974
+c
+c
+c     compute orthogonal rotation matrix..
+c     compute.. matrix	 (c, s) so that (c, s)(a) = (sqrt(a**2+b**2))
+c			 (-s,c) 	(-s,c)(b)   (	0	   )
+c     compute sig = sqrt(a**2+b**2)
+c	 sig is computed last to allow for the possibility that
+c	 sig may be in the same location as a or b .
+c
+      zero=0.
+      one=1.
+      if (abs(a).le.abs(b)) go to 10
+      xr=b/a
+      yr=sqrt(one+xr**2)
+      cos=sign(one/yr,a)
+      sin=cos*xr
+      sig=abs(a)*yr
+      return
+   10 if (b) 20,30,20
+   20 xr=a/b
+      yr=sqrt(one+xr**2)
+      sin=sign(one/yr,b)
+      cos=sin*xr
+      sig=abs(b)*yr
+      return
+   30 sig=zero
+      cos=zero
+      sin=one
+      return
+      end