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Aspect Ratio -> 1 and copy-and-paste of figures

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  • Subject: [mg72278] Aspect Ratio -> 1 and copy-and-paste of figures
  • From: Virgil Stokes <vs at>
  • Date: Mon, 18 Dec 2006 06:55:35 -0500 (EST)

I am using vers. on a Win2k platform and after some careful testing have 
found that the option AspectRatio in Graphics is not working properly on my system.

When I execute the following two commands (the first comes directly from Help on 
AspectRatio) the figure plotted on the screen (and on my printer's output) is 
not a circle.



For example on my home PC monitor, the displayed circles have a width 
(horizontal) of 9.05cm and a height (vertical) of 9.6cm which means that the 
"circle" is not plotted as a circle; but an ellipse (aspect ratio measured > 1). 
Note, I have been very careful in making these measurements directly on two 
different monitors and neither gives a perfect circle! I have also generated 
perfect circles in Corel Draw (vers. 13) and what is shown on my monitors and 
outputted to my printers are indeed perfect circles. Interestingly, if I copy 
and paste these circles into Corel Draw, they have an aspect ratio of 1.

However, when I copy and paste some of my other figures (created with 
AspectRatio->1, in Mathematica using Plot or ParametricPlot), edges of these are 
often lost and the aspect ratio is incorrect. I have been unable to identify any 
consistent pattern in the missing part of the image, except that it is often the 
lower right parts of the image. For example, if I plot some function in the 
region 0 <= x <= 6, 0 <= y <= 6, with an AspectRatio->1, and 
PlotRange->{{0,6},{0,6}} then again the height of the figure produced on my 
monitor is greater than its width. If I copy and paste this figure into Corel 
Draw, then the x-axis is terminated at x=5.4 (not at x=6 as in the figure shown 
in Mathematica) and the lower half of the tic labels along the x-axis are lost. 
The following code shows both these problems on my system:

vars = {x[t], y[t]};
f = x[t] (p - q*y[t]);
g = y[t] (-P + Q*x[t]);
eqns = {x'[t] == f, y'[t] == g}
p = 3.0; q = 2;
P = 2.5; Q = 1;
inits = {x[0] == 2.5, y[0] == 0.5};
sol = vars /. NDSolve[Join[eqns, inits], vars, {t, 0, 10}][[1]];
p0 = ParametricPlot[sol, {t, 0, 2.5}, PlotRange -> {{0, 6}, {0,
         6}}, AspectRatio -> Automatic, AxesLabel -> {"prey", "predator"}];

These two problems, loss of parts of a figure in a copy-and-paste, and incorrect 
display of aspect ratio may be related. I will be glad to provide a Mathematica 
notebook which contains further examples of both these problems.

--V. Stokes

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