new file mode 100644
--- /dev/null
+++ b/scripts/plot/bar.m
@@ -0,0 +1,84 @@
+function [xb, yb] = bar (x, y)
+
+# usage: [xb, yb] = bar (x, y)
+#
+# Given two vectors of x-y data, bar produces a bar graph.
+#
+# If only one argument is given, it is taken as a vector of y-values
+# and the x coordinates are taken to be the indices of the elements.
+#
+# If two output arguments are specified, the data are generated but
+# not plotted.  For example,
+#
+#   bar (x, y);
+#
+# and
+#
+#   [xb, yb] = bar (x, y);
+#   plot (xb, yb);
+#
+# are equivalent.
+#
+# See also: plot, semilogx, semilogy, loglog, polar, mesh, contour,
+#           stairs, gplot, gsplot, replot, xlabel, ylabel, title 
+
+  if (nargin == 1)
+    if (is_vector (x))
+      len = 3 * length (x) + 1;
+      xb = yb = zeros (len, 1);
+      xb(1) = 0.5;
+      yb(1) = 0;
+      k = 1;
+      for i = 2:3:len
+        xb(i) = k-0.5;
+        xb(i+1) = k+0.5;
+        xb(i+2) = k+0.5;
+        yb(i) = x(k);
+        yb(i+1) = x(k);
+        yb(i+2) = 0.0;
+        k++;
+      endfor
+    else
+      error ("bar: argument must be a vector");
+    endif
+  elseif (nargin == 2)
+    if (is_vector (x) && is_vector (y))
+      xlen = length (x);
+      ylen = length (y);
+      if (xlen == ylen)
+        len = 3 * xlen + 1;
+        xb = yb = zeros (len, 1);
+        delta = (x(2) - x(1)) / 2.0;
+        xb(1) = x(1) - delta;
+        yb(1) = 0.0;
+	k = 1;
+        for i = 2:3:len
+          xb(i) = xb(i-1);
+          xb(i+1) = xb(i) + 2.0 * delta;
+          xb(i+2) = xb(i+1);
+	  yb(i) = y(k);
+	  yb(i+1) = y(k);
+	  yb(i+2) = 0.0;
+          if (k < xlen)
+            delta = (x(k+1) - x(k)) / 2.0;
+            if (x(k+1) < x(k))
+              error ("bar: x vector values must be in ascending order");
+            endif
+          endif
+          k++;
+	endfor
+      else
+        error ("bar: arguments must be the same length");
+      endif
+    else
+      error ("bar: arguments must be vectors");
+    endif
+  else
+    error ("usage: [xb, yb] = bar (x, y)");
+  endif
+
+  if (nargout == 1)
+    plot (xb, yb);
+  endif
+
+endfunction