# HG changeset patch
# User jwe
# Date 931837776 0
# Node ID ae3bdfd82f918131c042be10e80ee828f3315d96
# Parent  60866c521b9293806c06bbe3bad3d88b672702cb
[project @ 1999-07-13 03:49:22 by jwe]

diff --git a/doc/interpreter/basics.texi b/doc/interpreter/basics.texi
--- a/doc/interpreter/basics.texi
+++ b/doc/interpreter/basics.texi
@@ -889,7 +889,7 @@
 @end deffn
 
 @defvr {Built-in Variable} echo_executing_commands
-This variable is may also be used to control the echo state.  It may be
+This variable may also be used to control the echo state.  It may be
 the sum of the following values:
 
 @table @asis
@@ -940,7 +940,7 @@
 case, Octave generated an error message because the keyword
 @code{function} was misspelled.  Instead of seeing @samp{function f},
 Octave saw two consecutive variable names, which is invalid in this
-context.  It marked the error at the @code{y} because the first name by
+context.  It marked the error at @code{y} because the first name by
 itself was accepted as valid input.
 
 Another class of error message occurs at evaluation time.  These
@@ -973,9 +973,10 @@
 In the example above, the first line indicates that a variable named
 @samp{x} was found to be undefined near line 1 and column 24 of some
 function or expression.  For errors occurring within functions, lines
-from the beginning of the file containing the function definition.  For
-errors occurring at the top level, the line number indicates the input
-line number, which is usually displayed in the prompt string.
+are counted from the beginning of the file containing the function
+definition.  For errors occurring at the top level, the line number
+indicates the input line number, which is usually displayed in the
+prompt string.
 
 The second and third lines in the example indicate that the error
 occurred within an assignment expression, and the last line of the error
diff --git a/doc/interpreter/diffeq.texi b/doc/interpreter/diffeq.texi
--- a/doc/interpreter/diffeq.texi
+++ b/doc/interpreter/diffeq.texi
@@ -20,7 +20,7 @@
 @node Ordinary Differential Equations, Differential-Algebraic Equations, Differential Equations, Differential Equations
 @section Ordinary Differential Equations
 
-The function @code{lsode} can be used Solve ODEs of the form
+The function @code{lsode} can be used to solve ODEs of the form
 @iftex
 @tex
 $$
@@ -122,7 +122,7 @@
 @node Differential-Algebraic Equations,  , Ordinary Differential Equations, Differential Equations
 @section Differential-Algebraic Equations
 
-The function @code{dassl} can be used Solve DAEs of the form
+The function @code{dassl} can be used to solve DAEs of the form
 @iftex
 @tex
 $$
diff --git a/scripts/ChangeLog b/scripts/ChangeLog
--- a/scripts/ChangeLog
+++ b/scripts/ChangeLog
@@ -1,3 +1,19 @@
+Mon Jul 12 22:48:34 1999  John W. Eaton  <jwe@bevo.che.wisc.edu>
+
+	* linear-algebra/cond.m: Avoid returning NaN for matrices that
+	contain only zeros.
+
+Sun Jun 20 22:24:27 1999  Eduardo Gallestey <eduardo@faceng.anu.edu.au>
+
+	* linear-algebra/kron.m: Create result matrix and insert blocks
+	instead of appending them.
+
+Sat Jun 19 01:52:18 1999  John W. Eaton  <jwe@bevo.che.wisc.edu>
+
+	* control/bodquist.m, control/buildssic.m, control/is_digital.m,
+	control/stepimp.m, control/sysmin.m, control/syssetsignals.m:
+	Update from A. S. Hodel.
+
 Fri Jun 18 12:19:22 1999  John W. Eaton  <jwe@bevo.che.wisc.edu>
 
 	* polynomial/polyfit.m: Correct previous change.
diff --git a/scripts/linear-algebra/cond.m b/scripts/linear-algebra/cond.m
--- a/scripts/linear-algebra/cond.m
+++ b/scripts/linear-algebra/cond.m
@@ -39,8 +39,18 @@
       endif
       retval = 0.0;
     endif
-    sigma = svd (a);
-    retval = sigma (1) / sigma (length (sigma));
+    if (any (any (isinf (a) | isnan (a))))
+      error ("cond: argument must not contain Inf or NaN values");
+    else
+      sigma = svd (a);
+      sigma_1 = sigma(1);
+      sigma_n = sigma(length (sigma));
+      if (sigma_1 == 0 || sigma_n == 0)
+	retval = Inf;
+      else
+	retval = sigma_1 / sigma_n;
+      endif
+    endif
   else
     usage ("cond (a)");
   endif
diff --git a/scripts/linear-algebra/kron.m b/scripts/linear-algebra/kron.m
--- a/scripts/linear-algebra/kron.m
+++ b/scripts/linear-algebra/kron.m
@@ -35,25 +35,17 @@
     [m, n] = size (b);
     [ma, na] = size (a);
 
-    ## Do 1st column.
-
-    x = a (1, 1) * b;
-    for ii = 2:ma
-      tmp = a (ii, 1) * b;
-      x = [x; tmp];
-    endfor
-
-    ## Do remaining columns.
+    x = zeros (ma*m, na*n);	
+    i_vec = 1:m;
+    j_vec = 1:n;
 
-    for jj = 2:na
-      tmp = a (1, jj) * b;
-      for ii = 2:ma
-        pmt = a (ii, jj) * b;
-	tmp = [tmp; pmt];
+    for jj = 1:na
+      for ii = 1:ma
+	x(i_vec+(ii-1)*m,j_vec) = a(ii,jj) * b;
       endfor
-      x = [x, tmp];
+      j_vec = jvec + n;
     endfor
-
+    
   else
     usage ("kron (a, b)");
   endif