--- a/doc/interpreter/plot.txi
+++ b/doc/interpreter/plot.txi
@@ -64,7 +64,7 @@
 command will open a separate plot window to display the graph.
 
 @float Figure,fig:plot
-@image{plot,8cm}
+@center @image{plot,4in}
 @caption{Simple Two-Dimensional Plot.}
 @end float
 
@@ -99,7 +99,7 @@
 shown in @ref{fig:hist}.
 
 @float Figure,fig:hist
-@image{hist,8cm}
+@center @image{hist,4in}
 @caption{Histogram.}
 @end float
 
@@ -141,18 +141,20 @@
 example,
 
 @example
+@group
 x = 0:0.1:10;
 y = sin (x);
 yp =  0.1 .* randn (size (x));
 ym = -0.1 .* randn (size (x));
 errorbar (x, sin (x), ym, yp);
+@end group
 @end example
 
 @noindent
 produces the figure shown in @ref{fig:errorbar}.
 
 @float Figure,fig:errorbar
-@image{errorbar,8cm}
+@center @image{errorbar,4in}
 @caption{Errorbar plot.}
 @end float
 
@@ -176,7 +178,7 @@
 produces the spiral plot shown in @ref{fig:polar}.
 
 @float Figure,fig:polar
-@image{polar,8cm}
+@center @image{polar,4in}
 @caption{Polar plot.}
 @end float
 
@@ -276,7 +278,7 @@
 is similar to @code{meshgrid}, but works for N-dimensional matrices.
 
 @float Figure,fig:mesh
-@image{mesh,8cm}
+@center @image{mesh,4in}
 @caption{Mesh plot.}
 @end float
 
@@ -299,7 +301,7 @@
 displays the spiral in three dimensions shown in @ref{fig:plot3}.
 
 @float Figure,fig:plot3
-@image{plot3,8cm}
+@center @image{plot3,4in}
 @caption{Three dimensional spiral.}
 @end float
 
@@ -442,10 +444,12 @@
 For example
 
 @example
+@group
 figure (1);
 fplot (@@sin, [-10, 10]);
 figure (2);
 fplot (@@cos, [-10, 10]);
+@end group
 @end example
 
 @noindent
@@ -801,19 +805,19 @@
 
 @item key
 Either @code{"on"} or @code{"off"} to toggle display of the legend.
-Note that this property is not compatible with @sc{Matlab} and may be
+Note that this property is not compatible with @sc{matlab} and may be
 removed in a future version of Octave.
 
 @item keybox
 Either @code{"on"} or @code{"off"} to toggle display of a box around the
-legend.  Note that this property is not compatible with @sc{Matlab} and
+legend.  Note that this property is not compatible with @sc{matlab} and
 may be removed in a future version of Octave.
 
 @item keypos
 An integer from 1 to 4 specifying the position of the legend.  1
 indicates upper right corner, 2 indicates upper left, 3 indicates lower
 left, and 4 indicates lower right.  Note that this property is not
-compatible with @sc{Matlab} and may be removed in a future version of
+compatible with @sc{matlab} and may be removed in a future version of
 Octave.
 
 @item dataaspectratio
@@ -949,7 +953,7 @@
 
 @item keylabel
 The text of the legend entry corresponding to this line.  Note that this
-property is not compatible with @sc{Matlab} and may be removed in a
+property is not compatible with @sc{matlab} and may be removed in a
 future version of Octave.
 @end table
 
@@ -1232,7 +1236,7 @@
 The result of which can be seen in @ref{fig:extendedtext}
 
 @float Figure,fig:extendedtext
-@image{extended,8cm}
+@center @image{extended,4in}
 @caption{Example of inclusion of text with the @sc{TeX} interpreter}
 @end float
 @end ifnotinfo
@@ -1299,7 +1303,7 @@
 
 @item keylabel
 The text of the legend entry corresponding to this surface.  Note that
-this property is not compatible with @sc{Matlab} and may be removed in a
+this property is not compatible with @sc{matlab} and may be removed in a
 future version of Octave.
 @end table
 
@@ -1492,11 +1496,13 @@
 be passed after the 2 default arguments.  For example
 
 @example
+@group
 plot (x, "DeleteFcn", @{@@mycallback, "1"@})
 @dots{}
 function mycallback (src, data, a1)
   fprintf ("Closing plot %d\n", a1);
 endfunction
+@end group
 @end example
 
 The basic callback functions that are available for all graphics objects