# HG changeset patch
# User jwe
# Date 745020770 0
# Node ID cd5ac1c52ea605138a3bfd1be28e7e39ac106821
# Parent  2947a1ad8ca3066f9f35d99ed08956f833205d10
[project @ 1993-08-10 22:12:50 by jwe]

diff -r 2947a1ad8ca3 -r cd5ac1c52ea6 src/builtins.cc
--- a/src/builtins.cc	Tue Aug 10 22:12:50 1993 +0000
+++ b/src/builtins.cc	Tue Aug 10 22:12:50 1993 +0000
@@ -509,6 +509,9 @@
   { "svd", 2, 3, builtin_svd,
     "[U,S,V] = svd(X): return SVD of X\n", },
 
+  { "syl", 4, 1, builtin_syl,
+    "X = syl (A, B, C): solve the Sylvester equation A X + X B + C = 0\n", },
+
   { "warranty", 1, 0, builtin_warranty,
     "describe copying conditions\n", },
 
diff -r 2947a1ad8ca3 -r cd5ac1c52ea6 src/g-builtins.cc
--- a/src/g-builtins.cc	Tue Aug 10 22:12:50 1993 +0000
+++ b/src/g-builtins.cc	Tue Aug 10 22:12:50 1993 +0000
@@ -68,6 +68,7 @@
 #include "f-rand.h"
 #include "f-schur.h"
 #include "f-svd.h"
+#include "f-syl.h"
 
 #include "procstream.h"
 #include "error.h"
@@ -1573,6 +1574,23 @@
 }
 
 /*
+ * Sylvester equation solver.
+ */
+tree_constant *
+builtin_syl (tree_constant *args, int nargin, int nargout)
+{
+  tree_constant *retval = NULL_TREE_CONST;
+
+  if ((nargin == 4) && (nargout == 1))
+    DLD_BUILTIN (args, nargin, nargout, syl,
+		 retval = syl (args, nargin, nargout);)
+  else
+    usage ("X = syl (A,B,C)");
+
+  return retval;
+}
+
+/*
  * Schur Decomposition
  */
 tree_constant *
diff -r 2947a1ad8ca3 -r cd5ac1c52ea6 src/g-builtins.h
--- a/src/g-builtins.h	Tue Aug 10 22:12:50 1993 +0000
+++ b/src/g-builtins.h	Tue Aug 10 22:12:50 1993 +0000
@@ -114,6 +114,7 @@
 extern tree_constant *builtin_sum (tree_constant *, int, int);
 extern tree_constant *builtin_sumsq (tree_constant *, int, int);
 extern tree_constant *builtin_svd (tree_constant *, int, int);
+extern tree_constant *builtin_syl (tree_constant *, int, int);
 extern tree_constant *builtin_warranty (tree_constant *, int, int);
 extern tree_constant *builtin_zeros (tree_constant *, int, int);