Questions relate to 'sunpy.map', draw map contours by using 'set_levels'

Hi everyone, I am currently using ‘sunpy.map’ to analysing LOFAR tied array image. After I generated a map from a LOFAR tied array dataset, I create a composite map to overplot the LOFAR and the AIA images. The composite map is called ‘my_map’

I learned that I can use ‘my_maps.set_levels(1, [75], percent=True)’ to generate contours directly. However, I found contours are too thin and dark to see right now, and I don’t know how to change the linewidth and the colour.

Another question: if there is a way to plot the centroid of the contour?

Many thanks,
Jinge

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Hi Jinge, thanks for asking here!

For customising contours, I don’t think there is an easy way, and your post has led me to a bug in sunpy that we would need to fix first: No way to specify line colors for a CompositeMap plot that includes contours · Issue #5455 · sunpy/sunpy · GitHub

I would recommend not using a composite map to do this, but instead keeping two different sunpy maps (an AIA one, and a LOFAR one). There is an example of drawing contours here: Overplotting HMI Contours on an AIA Image — SunPy 3.0.1 documentation - hopefully that does what you want, and you can customise the contours using arguments to the draw_contours call.

For plotting the centroid have you calculated the centroid already and just want to plot it, or do you need to calculate the centroid too?

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Thank you very much David!