diff scripts/special-matrix/vander.m @ 4:b4df021f796c

[project @ 1993-08-08 01:26:08 by jwe] Initial revision
author jwe
date Sun, 08 Aug 1993 01:26:08 +0000
parents
children 16a24e76d6e0
line wrap: on
line diff
new file mode 100644
--- /dev/null
+++ b/scripts/special-matrix/vander.m
@@ -0,0 +1,32 @@
+function retval = vander (c)
+
+# usage: vander (c)
+#
+# Return the Vandermonde matrix whose next to last column is c.
+#
+# See also: hankel, hadamard, hilb, invhilb, toeplitz
+
+  if (nargin != 1)
+    error ("usage: vander (c)");
+  endif
+
+  nr = rows (c);
+  nc = columns (c);
+  if (nr == 1 && nc == 1)
+    retval = 1;
+  elseif (nr == 1 || nc == 1)
+    n = length (c);
+    if (n > 0)
+      retval = zeros (n, n);
+      for i = 1:n
+        tmp = c(i);
+        for j = 1:n
+          retval (i, j) = tmp ^ (n - j);
+        endfor
+      endfor
+    endif
+  else
+    error ("vander: argument must be a vector");
+  endif
+
+endfunction