I would like to select areas under a particular circular radius in QGIS. I believe this is accomplished with the buffer tool, but when I specify the radius the area is not circular.

How to make them circular?


If you buffer a point, the result will be a circle only as long as you don't re-project the layer.

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I guess you have on-thy-fly re-projection enabled. Try turning it off.

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    They just change their location. Use "zoom to layer extent" to find them again. – underdark Mar 6 '11 at 18:16
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    The google maps raster layer cannot be reprojected on the fly. If you want circular buffers on top of your Google map, re-project you point vector layer to "Google Mercator" and re-apply the buffer. – underdark Mar 6 '11 at 18:24
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    I'm not sure how to do that or what it means. Looks like I'm going to have to learn about GIS more thoroughly. – Robertg Mar 6 '11 at 18:31
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    Right-click on the layer you want to buffer, select "Save as ...". Enter target file name and chose Google Mercator coordinate system. Load the new layer and buffer it. Then you should have circles on top of google maps. – underdark Mar 6 '11 at 18:40
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    Just make sure that both layers are in the same coordinate system. – underdark Mar 6 '11 at 19:21

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