Re: Stem update, rough guess.

[Daniel J Sebald]

Shai Ayal wrote:
> On 4/6/07, John W. Eaton <address@hidden> wrote:
>
> > Checking that the color is not empty is the thing to do.

OK; as it is then.

> > | Also, I don't really follow the hh, hhh, hhhh handle stuff.  My way
> > | of thinking is that plot() should now assign that correctly if
> > | everything is done with one plot command.  So I've put comment
> > | characters in front of all those lines and someone else can evaluate
> > | if that is really needed.
> >
> > I don't know what that is all about either.  We should probably be
> > setting the markerfacecolor property if dofill is true, but that
> > property is not handled in the graphics.cc file or by __go_draw_axes__

The stem.m help doesn't indicate what "fill" means.  I don't know how one fills 
a stem plot.  Color in the circle?  But that is a different symbol in the list 
of options.  (There is mention of "bar" in the help, maybe that is what fill 
pertains to.)

> > yet.  I have no idea what the intent was for plotting an additional
> > line using the axis limits.
>
>
> The intent: If the plotted vector has both negative and positive
> values (say sin(1:10)) this would plot a line at y=0 to show where the
> axis zero is. Why this is important I do not know. Maybe it's a Matlab
> compatibility thing ?

OK, yes that is this part:

#  if (find (y < 0))
#    x_axis_range = get (gca, "xlim");
#    hhhh = line (x_axis_range, [0, 0], "color", [0, 0, 0]);
# endif

In gnuplot that is handled with a separate "set", and I'm guessing this axis 
line might be a property for the matryoshka pointers.  So, what I've done in the 
attached patch is use the fputs/__plot_stream__ mechanism as an illustration. 
I've made the line half size so it doesn't stand out so.  If this makes sense, 
then this can be moved into __go_draw_axes__ with some new type of property.

Now, in the examples for stem.m I see this one:

## @example
## x = 1:10;
## y = ones (size (x))*2.*x;
## h = stem (x, y, "b");
## @end example
## @noindent
## plots 10 bars with heights from 2 to 20

Bars are certainly possible with gnuplot, but isn't "b" conflicting with the 
plot option "blue" which is "b"?

Dan

--- /usr/local/share/octave/2.9.10+/m/plot/stem.m       2007-04-05 
16:23:29.000000000 -0500
+++ ./stem.m    2007-04-06 18:19:35.923707853 -0500
@@ -19,7 +19,7 @@
 
 ## -*- texinfo -*-
 ## @deftypefn {Function File} address@hidden =} stem (@var{x}, @var{y}, 
@var{linespec})
-## Plot a stem graph and return the handles of hte line and marker
+## Plot a stem graph and return the handles of the line and marker
 ## objects used to draw the stems.  The default color is @code{"r"}
 ## (red). The default line style is @code{"-"} and the default marker is
 ## @code{"o"}.
@@ -30,7 +30,7 @@
 ## stem (x);
 ## @end example
 ## @noindent
-## plots 10 stems with hights from 1 to 10;
+## plots 10 stems with heights from 1 to 10;
 ##
 ## @example
 ## x = 1:10;
@@ -38,7 +38,7 @@
 ## stem (x, y);
 ## @end example
 ## @noindent
-## plots 10 stems with hights from 2 to 20;
+## plots 10 stems with heights from 2 to 20;
 ## 
 ## @example
 ## x = 1:10;
@@ -46,7 +46,7 @@
 ## h = stem (x, y, "b");
 ## @end example
 ## @noindent
-## plots 10 bars with hights from 2 to 20
+## plots 10 bars with heights from 2 to 20
 ## (the color is blue, and @var{h} is a 2-by-10 array of handles in
 ## which the first row holds the line handles and the 
 ## the second row holds the marker handles);
@@ -57,7 +57,7 @@
 ## h = stem (x, y, "-.k");
 ## @end example
 ## @noindent
-## plots 10 stems with hights from 2 to 20
+## plots 10 stems with heights from 2 to 20
 ## (the color is black, line style is @code{"-."}, and @var{h} is a 2-by-10
 ## array of handles in which the first row holds the line handles and
 ## the second rows holds the marker handles);
@@ -68,7 +68,7 @@
 ## h = stem (x, y, "-.k.");
 ## @end example
 ## @noindent
-## plots 10 stems with hights from 2 to 20
+## plots 10 stems with heights from 2 to 20
 ## (the color is black, line style is @code{"-."} and the marker style
 ## is @code{"."}, and @var{h} is a 2-by-10 array of handles in which the
 ## first row holds the line handles and the second row holds the marker
@@ -80,7 +80,7 @@
 ## h = stem (x, y, "fill");
 ## @end example
 ## @noindent
-## plots 10 stems with hights from 2 to 20
+## plots 10 stems with heights from 2 to 20
 ## (the color is rgb-triple defined, the line style is @code{"-"},
 ## the marker style is @code{"o"}, and @var{h} is a 2-by-10 array of
 ## handles in which the first row holds the line handles and the second
@@ -102,42 +102,38 @@
 
   [x, y, dofill, lc, ls, mc, ms] = check_stem_arg (varargin{:});
 
-  newplot ();
+  ## FIXME:  If marker that can be filled, choose the filled option.  This
+  ## isn't the best way to do this.  Remove when the "markerfacecolor" option
+  ## below is fully implemented.
+  if (dofill)
+    if (ms == "o")
+      ms = ".";
+    elseif (ms == ">")
+      ms = "^";
+    elseif (ms == "<")
+      ms = "v";
+    elseif (ms == "p")
+      ms = "s";
+    endif
+  endif
 
-  ## first, plot the lines.. without marker
-  ## Use a loop and calls to line here because setting properties this
-  ## way doesn't work with plot yet.
-  idxhh = 0;
-  for i = 1:numel(x)
-    hh(++idxhh) = line ([x(i); x(i)], [0; y(i)], "color", lc, "linestyle", ls);
-  endfor
+  newplot ();
 
-  ## second, plot the markers..
-  hhh = [];
-  hhhh = [];
-
-  ## Use a loop and calls to line here because setting properties this
-  ## way doesn't work with plot yet.
-  idxhhh = 0;
-  for i = 1:numel(x)
-    hhh(++idxhhh) = line ([x(i); x(i)], [y(i); y(i)]);
-  endfor
+  h = plot ([x(:) x(:)]', [zeros(size(x(:))) y(:)]', "color", lc, "linestyle", 
ls, x, y, "color", mc, "marker", ms, "linestyle", "");
 
-  if (find (y < 0))
-    x_axis_range = get (gca, "xlim");
-    hhhh = line (x_axis_range, [0, 0], "color", [0, 0, 0]);
-  endif
+  ## FIXME:  A property should be added to the handle list for the following.
+#  set (gca, "?axisline?", "on");
+  ## Note that the first time this is called, the __plot_stream__ = []
+  ## so there will be an error.  (Could the plot stream be initialized inside
+  ## newplot.m rather than __go_draw_axes__.m?)
+#  fputs( get (gcf, "__plot_stream__"), "set xzeroaxis;\nreplot;\n");
+  fputs( get (gcf, "__plot_stream__"), "set xzeroaxis linetype -1 linewidth 
0.5;\nreplot;\n");
 
   if (dofill)
-    set (hhh, "markerfacecolor", mc);
+    set (h, "markerfacecolor", mc);
   endif
 
-  if (nargout > 0)
-    if (! isempty (hhhh))
-      hhhh = hhhh*(ones (length (hh), 1))';
-    endif
-    h = [hh; hhh; hhhh];
-  endif
+  ## FIXME:  WHAT IS A HANDLE GROUP THAT SHOULD BE RETURNED?
 
 endfunction
 
@@ -279,11 +275,11 @@
   for i = 1:length(cur_props)
     if (isfield (cur_props(i), "markeredgecolor"))
       mc = cur_props(i).markeredgecolor;
-    elseif (isfield (cur_props(i), "color")); # means line color
+    elseif (isfield (cur_props(i), "color") && ! isempty 
(cur_props(i).color)); # means line color
       lc = cur_props(i).color;
     elseif (isfield (cur_props(i), "linestyle"))
       ls = cur_props(i).linestyle;
-    elseif (isfield (cur_props(i), "marker"))
+    elseif (isfield (cur_props(i), "marker") && ! strcmp (cur_props(i).marker, 
"none"))
       ms = cur_props(i).marker;
     endif
   endfor