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Hi, I am faced with a problem on the task imsurfit. If I set 'circle' in its 'region' option, it can only work for one circle. But I have a number of circles in images, what should I do? In fact, what I want to do is to fit regions exterior to the circles.Thank you very much in advance!

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Center for Astrophysics University of Science and Technology of China Hefei, Anhui 230026, China

Hi,Imsurfit is limited to a single circle though regions="imvcircle" can fit to the exterior of the circle.The current alternative to suggest is mscskysub in the mscred package. This is a version of imsurfit that allows use of masks. There is no help page but it is the same as imsurfit except the regions can be "mask" and the "residual" output type is slightly different in that the mean of the fit is excluded so that the mean level of the residual image is unchanged. This version also works with multiextension and well as single images.To make the mask you can use many tools but I might point out mskregions as possible of use to you.Yours,
Frank Valdes