[AstroPy] APLpy color bar for markers

[Thøger Emil Rivera-Thorsen]

My fault, a typo again (I hit ‘send’ too fast, it seems).
Let me try and get it right this time:

|import matplotlib.pyplot as plt import aplpy as ap f = plt.figure() fig 
= ap.FITSFigure('/path/to/myimage.fits', figure=f) a = f.axes[0] # Or 
alternatively, a = plt.gca() x, y = fig.world2pixel(ra, dec) points = 
a.scatter(x, y, c=velocity, cmap='rainbow') f.colorbar(points, ax=a, 
use_gridspec=True) |

I had forgotten to pass the |points| object to the |colorbar()| call.
Should work now - I hope.

Cheers!

On 03/07/2016 10:03 PM, Ke Wang wrote:

> Thank you Thøger!
> I got this error, which I don't understand. Any idea ?
>
> In [19]: f.colorbar(ax=a, use_gridspec=True)
> ---------------------------------------------------------------------------
> TypeError                                 Traceback (most recent call 
> last)
> <ipython-input-19-a7064055af74> in <module>()
> ----> 1 f.colorbar(ax=a, use_gridspec=True)
>
> TypeError: colorbar() takes at least 2 arguments (3 given)
>
>
> ---
> Dr. Ke Wang
> Associate, European Southern Observatory
> http://www.eso.org/~kwang <http://www.eso.org/%7Ekwang>
>
> On Mon, Mar 7, 2016 at 6:55 PM, Thøger Emil Rivera-Thorsen 
> <trive at astro.su.se <mailto:trive at astro.su.se>> wrote:
>
>     Sorry for flooding, but I just worked out a better solution:
>
>     |import matplotlib.pyplot as plt import aplpy as ap f =
>     plt.figure() fig = ap.FITSFigure('/path/to/myimage.fits',
>     figure=f) a = fig.axes[0] # Or alternatively, a = plt.gca() x, y =
>     fig.world2pixel(ra, dec) points = a.scatter(x, y, c=velocity,
>     cmap='rainbow') f.colorbar(ax=a, use_gridspec=True) |
>
>     This should give you what you want, and look a good deal nicer
>     than my first suggestion.
>     You can set the width etc. of the colorbar in the |f.colorbar()|
>     call, just read the documentation (|f.colorbar?| in IPython).
>
>     On 03/07/2016 06:38 PM, Thøger Emil Rivera-Thorsen wrote:
>
>>     I would do this by tapping directly into the Matplotlib/pylab api
>>     to do this:
>>
>>     |import matplotlib.pyplot as plt import aplpy as ap fig =
>>     ap.FITSFigure('myimage.fits') fig.show_grayscale() f, a =
>>     plt.gcf(), plt.gca() x, y = fig.world2pixel(ra, dec) points =
>>     a.scatter(ra, dec, c=velocity, cmap='rainbow') fig.colorbar(points) |
>>
>>     The colorbar is not as neatly aligned as the APLPy function does,
>>     but this can be refined and tweaked, if you read the matplotlib
>>     docs (or you can just use it as-is).
>>
>>     On 03/07/2016 04:52 PM, Ke Wang wrote:
>>
>>>     Hi,
>>>
>>>     This should be a simple question, but I just don't find an
>>>     obvious solution:
>>>
>>>     I use APLpy to plot a FITS image with nice wcs coordinates
>>>     support, and overlay color coded markers:
>>>
>>>     fig = aplpy.FITSFigure('image.fits')
>>>     fig.show_colorscale(cmap='gray')
>>>     fig.show_markers(ra, dec, c=velocity, cmap='rainbow')
>>>     fig.add_colorbar()
>>>
>>>     This will plot a gray color bar (for the image). But I want to
>>>     display the rainbow (for markers). Any idea would be appreciated.
>>>
>>>     Cheers,
>>>     Ke
>>>
>>>
>>>     _______________________________________________
>>>     AstroPy mailing list
>>>     AstroPy at scipy.org <mailto:AstroPy at scipy.org>
>>>     https://mail.scipy.org/mailman/listinfo/astropy
>>     ​
>>
>>
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>     ​
>
>
>
>
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