extractAzimuthalAverageFromImage

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This function computes the radial profile of an image (or 2 or 3) by considering all points with respect to the image center, or any specified pixel. This is a front-end function for au.azimuthalAverage. It was used to create the ALMA Band 3 beam radial profiles (see CAS-3532).

Usage:

au.extractAzimuthalAverageFromImage(image1, image2=None, image3=None, 
         center=None, binsize=1.0, xlimits=[0,0], panels=1, mirror=False, 
         peakimage=None, channel=0, stokes='XX', showplot=True, outfile='',
         plotfile='', normalize=True, scaleToArcsec=True,
         useimfit=True, interpolateToZero=False, maxradius=180)
Inputs:
  • image1: the image to analyze
  • image2: an optional second image to include as another column in the output
  • image3: an optional third image to include as another column in the output
  • center: specify the point about which to compute the average (default = image center)
  • binsize: passed to azimuthalAverage
  • xlimits: the x-axis limits to use if showplot==True
  • panels: if 2, then also show intensity in dB in a second plot panel
  • mirror: reflect the profile about x=0
  • peakimage: the image for which to automatically find the peak to use as center
  • channel: the channel of the peakimage to use
  • stokes: the polarization product of the peak image to use ('XX', 'XY, 'YX', or 'YY')
  • showplot: if True, open a graphics window showing the profile
  • outfile: the text file to write the profile to
  • plotfile: the graphics file to generate
  • normalize: if True, then divide profiles by peak of peakimage
  • scaleToArcsec: if True, read cdelt2 from image1 and scale x-axis by this value in arcsec
  • useimfit: if True, use imfit instead of imstat to find the peak of peakimage
  • interpolateToZero: insert an entry at radius=0 as avg of 0th and 1st order extrapolation
  • maxradius: stop writing to outfile beyond this point (in arcsec if scaleToArcsec==True)

Example:

au.extractAzimuthalAverageFromImage('ALMA_0_DA__0_0_360_0_45_90_92_100_108_GHz_ticra2007_EFP.im.real',
'ALMA_0_DA__0_0_360_0_45_90_92_100_108_GHz_ticra2007_EFP.im.imaginary',
'ALMA_0_DA__0_0_360_0_45_90_92_100_108_GHz_ticra2007_EFP.im.amplitude',
stokes='XX',outfile='band3_DA_XX.dat',maxradius=180,interpolateToZero=True,
peakimage='ALMA_0_DA__0_0_360_0_45_90_92_100_108_GHz_ticra2007_EFP.im.amplitude',
plotfile='band3_DA_XX.png') 

-- ToddHunter - 2014-02-26
  • band3_DA_XX.png:
    band3 DA XX.png
Topic revision: r2 - 2014-03-04, ToddHunter
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