Re: Detect automatically chosen value for PlotRange in Epilog?
- To: mathgroup at smc.vnet.net
- Subject: [mg105827] Re: [mg105793] Detect automatically chosen value for PlotRange in Epilog?
- From: "David Park" <djmpark at comcast.net>
- Date: Sun, 20 Dec 2009 06:56:53 -0500 (EST)
- References: <12890052.1261223184684.JavaMail.root@n11>
Those who have the Presentations package can do this in the following
manner. The specification uses the Presentations routine DrawingWidths2D.
DrawingWidths2D[{primitives}] will return the widths, center point and
bounds of the bounding box that contains the list of primitives.
I also changed the example somewhat such that the drawing routine would not
know the width of the plot in advance.
Needs["Presentations`Master`"]
plotExample[a_?NumericQ] :=
Module[
{xmin, xmax, maingraphics},
(* Draw the main part of the graphic *)
maingraphics = ParametricDraw[{a Sin[y], y}, {y, -3, 3}];
(* Find the limits of x plot range *)
{xmin, xmax} = Part[DrawingWidths2D[maingraphics], 3, 1];
Draw2D[
{maingraphics,
(* Draw the arrows for the given x range only *)
Red, Arrow[{{#, 0}, {#, 1}}] & /@
Range[Floor[xmin], Ceiling[xmax]]},
Frame -> True,
Axes -> True, AxesStyle -> GrayLevel[.7],
AxesStyle -> GrayLevel[.7]]
]
plotExample[4.5]
It's too bad that Frame -> True is not the default for all Mathematica plots
that use scales. Axes plots are usually quite poor because the axes and tick
values stomp all over the data. The data is the important thing. It is very
difficult to find axes plots in journals such as Science - unless the origin
is at the lower left hand corner.
David Park
djmpark at comcast.net
http://home.comcast.net/~djmpark/
From: Chris Rodgers
[mailto:see-rodgers-org-uk-for-contact-details at invalid.gg]
Hi,
I want to add some arrows to a plot, like this:
Plot[0, {x, -5, 5},
Epilog -> {Red, Arrow[{{#, 0}, {#, 1}}] & /@ Range[-10, 500]}]
When plotting more complicated functions, can I detect inside Epilog
what value Mathematica chose for the PlotRange?
I looked at AbsoluteOptions[...], but I don't know how to get the handle
for the currently plotting graphics object.
My aim is to restrict my arrow drawing so that I only attempt to draw
arrows that will actually appear in the plot. I hope this will speed
things up.
Thanks,
Chris.