# How can I get Overlay to position graphics according to coordinates?

If I draw graphics like this, I get exactly what I need:

Graphics[{{Blue, Disk[{0, 0}, 10, {0, Pi/2}]}, {Red,
Disk[{0, 0}, 3, {0, Pi/4}]}}]


But I need to accomplish this task with Overlay[]. Here's the code:

graphics1 = Graphics[{Red, Disk[{0, 0}, 3, {0, Pi/4}]}];
graphics2 = Graphics[{Blue, Disk[{0, 0}, 10, {0, Pi/2}]}];
Overlay[{graphics2, graphics1}]


And I get this as output:

How can I position these graphics according to coordinates?
Thank you for any suggestions or answers.

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Why does it have to be Overlay specifically? I think what you are looking for combining multiple Graphics objects to one, for which Overlay is not the right function. –  David Jan 18 '12 at 0:41
Indeed it does not have to be 'Overlay', I didn't think of 'Show' –  balboa Jan 18 '12 at 11:46

You can get the desired result using a combination of ImageSize in the original image and the Alignment option in Overlay. (I am not 100% sure why the alignment isn't quite right.)

graphics1 =
Graphics[{Red, Disk[{0, 0}, 3, {0, Pi/4}]}, ImageSize -> 100];
graphics2 =
Graphics[{Blue, Disk[{0, 0}, 10, {0, Pi/2}]}, ImageSize -> 250];
Overlay[{graphics2, graphics1}, Alignment -> Bottom]


The issue here is that overlay will set the sizes of the two images to be the same if it has no information requiring it to do otherwise. So the coordinate systems of the two graphics can differ. This is why Show works more seamlessly here: it forces the two graphics to have the same coordinate system.

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I encountered the same problem with Alignment, but you're right Show is much more appropriate approach than Overlay is for this task, thank you for answer –  balboa Jan 18 '12 at 12:01

Can you use Show? It produces the same thing as your first plot:

Graphics1 = Graphics[{Red, Disk[{0, 0}, 3, {0, Pi/4}]}];
graphics2 = Graphics[{Blue, Disk[{0, 0}, 10, {0, Pi/2}]}];
Show[{graphics2, graphics1}]


If you want to add other options, it works as well:

Show[{graphics2, graphics1}, PlotRange->{{-10, +10}, {-10, +10}}]


You should note that Show is order dependent. It draws it in the order that's specified

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Thank you, that solved my problem. –  balboa Jan 18 '12 at 11:48
@balboa Hi, seems you forgot to accept this answer :) –  ssch Sep 13 '13 at 0:32