Axes Plotting Issue

[EDrabek]

Hi,

I am having an issue when attempting to plot a position-velocity diagram (x-axis position using an offset axis I created in arc min and y-axis in velocity). The program runs smoothly and outputs a plot, but the axes are wrong. I believe the x-axis is centred correctly at CPIX1 but the labels seem to be in pixels and I'm unsure about the y-axis. Here is the snippet of the program I am using:

def pv_plot(pvhdulist,plotname): pvplotdata=numpy.where(pvhdulist[0].data>=0,numpy.sqrt(pvhdulist[0].data),0) fig=plt.figure() ax=pywcsgrid2.axes_wcs.AxesWcs(fig,[0.2,0.2,0.7,0.7],header=pvhdulist[0].header) ax.set_ticklabel1_type("absval",nbins=5) ax.set_ticklabel2_type("absval",scale=0.001,nbins=9) pylab.imshow(pvplotdata, origin="low", interpolation="nearest", aspect=0.04, vmin=0, vmax=10,cmap=pylab.cm.gist_heat) plt.savefig(plotname+".png",dpi=300,orientation="landscape",transparent="True",bbox_inches="tight")

No matter how I change with ax.set_ticklabel1_type (if I change it to "arcmin" and choose an offset for example for the x-axis), the axes ticks do not change.

Has this problem been encountered before?

[leejjoon]

My guess is that you're creating an axes but not adding it to a figure. So, imshow creates its own.

See if adding this line helps. This needs to be added after you create an axes with AxesWcs.

fig.add_axes(ax)

If this does not help, please post an simple but complete code.

[EDrabek]

I included your suggestion and received the following error:

Traceback (most recent call last): File "run_PV_outflow.py", line 21, in PV_outflow.pv_plot(pv_input,test_pv_output) File "/Users/emily/PV_outflow.py", line 70, in pv_plot fig.add_axes(ax) File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/figure.py", line 683, in add_axes key = self._make_key(_args, _kwargs) File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/figure.py", line 630, in _make_key key = fixlist(args), fixitems(kwargs.items()) File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/figure.py", line 626, in fixlist if iterable(a): a = tuple(a) File "/Library/Python/2.7/site-packages/pywcsgrid2/axes_wcs.py", line 1270, in getitem key = proj.sub([1,2]) File "/Library/Python/2.7/site-packages/pywcsgrid2/wcs_helper.py", line 240, in sub return self.substitute(axis_nums_to_keep, [0] \ self.naxis) File "/Library/Python/2.7/site-packages/pywcsgrid2/wcs_helper.py", line 264, in _get_naxis return self._pywcs.wcs.naxis AttributeError: 'int' object has no attribute 'wcs'

[leejjoon]

Okay, this is something that has been fixed in the master branch. I just pushed new release (v0.1b2) that I believe fixes this bug. Please try it (you should be able to download it from the download page) and see if it works.

[EDrabek]

It seems to have been fixed! Thank you for your quick response. Cheers.