1 files changed, 51 insertions, 0 deletions
diff --git a/newlib/libm/complex/catan.c b/newlib/libm/complex/catan.c
index 9e29b128e..2cb91bb08 100644
--- a/newlib/libm/complex/catan.c
+++ b/newlib/libm/complex/catan.c
@@ -32,6 +32,57 @@
  * Marco Atzeri <marco_atzeri@yahoo.it>
  */
 
+/*
+FUNCTION
+        <<catan>>, <<catanf>>---complex arc tangent
+
+INDEX
+        catan
+INDEX
+        catanf
+
+ANSI_SYNOPSIS
+       #include <complex.h>
+       double complex catan(double complex <[z]>);
+       float complex catanf(float complex <[z]>);
+
+
+DESCRIPTION
+        @ifnottex
+        These functions compute the complex arc tangent of <[z]>,
+        with branch cuts outside the interval [-i, +i] along the 
+        imaginary axis.
+        @end ifnottex
+        @tex
+        These functions compute the complex arc tangent of <[z]>,
+        with branch cuts outside the interval [$-i$, $+i$] along the 
+        imaginary axis.
+        @end tex
+
+        <<catanf>> is identical to <<catan>>, except that it performs
+        its calculations on <<floats complex>>.
+
+RETURNS
+        @ifnottex
+        These functions return the complex arc tangent value, in the range
+        of a strip mathematically  unbounded  along the imaginary axis
+        and in the interval [-pi/2, +pi/2] along the real axis.
+        @end ifnottex
+        @tex
+        These functions return the complex arc tangent, in the range
+        of a strip mathematically  unbounded  along the imaginary axis
+        and in the interval [$-\pi/2$, $+\pi/2$] along the real axis.
+        @end tex
+
+PORTABILITY
+        <<catan>> and <<catanf>> are ISO C99
+
+QUICKREF
+        <<catan>> and <<catanf>> are ISO C99
+
+*/
+
+
 #include <complex.h>
 #include <math.h>
 #include "cephes_subr.h"