--- a/doc/interpreter/sparse.txi	Wed Mar 08 22:57:20 2006 +0000
+++ b/doc/interpreter/sparse.txi	Thu Mar 09 15:12:21 2006 +0000
@@ -592,9 +592,14 @@
 
 The standard Cholesky factorization of this matrix, can be
 obtained by the same command that would be used for a full
-matrix. This can be visualized with the command @code{r =
-chol(A); spy(r);}, @xref{fig:simplechol}. The original matrix
-had 
+matrix. This can be visualized with the command 
+@code{r = chol(A); spy(r);}.
+@ifset HAVE_CHOLMOD
+@ifset HAVE_COLAMD
+@xref{fig:simplechol}.
+@end ifset
+@end ifset
+The original matrix had 
 @ifinfo
 @ifnothtml
 43
@@ -995,8 +1000,14 @@
 Finally, in order to display the solution, we show each solved voltage 
 value in the z-axis for each simplex vertex.
 @ifset htmltex
+@ifset HAVE_CHOLMOD
+@ifset HAVE_UMFPACK
+@ifset HAVE_COLAMD
 @xref{fig:femmodel}.
 @end ifset
+@end ifset
+@end ifset
+@end ifset
 
 @example
   elemx = elems(:,[1,2,3,1])';