Can't load PV diagram with just an RA axis

[keflavich]

Opening a file with this header:

SIMPLE  =                    T / conforms to FITS standard
BITPIX  =                  -64 / array data type
NAXIS   =                    2 / number of array dimensions
NAXIS1  =                  729
NAXIS2  =                  266
BMAJ    = 0.000300056855542465
BMIN    = 0.000231425445281507
BPA     =    87.93917508585434
FILENAME= 'G351.77_B6_spw1_12M_spw1.model'
BUNIT   = 'beam-1 Jy'
SLICE   = '[[(0, 959, None), (64, 801, None), (136, 865, None)]]'
BEAM    = 'Beam: BMAJ=1.080204679952874 arcsec BMIN=0.8331316030134253 arcsec &'
CONTINUE  'BPA=87.93917508585434 deg'
WCSAXES =                    2 / Number of coordinate axes
CRPIX1  =                365.0 / Pixel coordinate of reference point
CRPIX2  =                  1.0 / Pixel coordinate of reference point
CDELT1  = -4.7222222222222E-05 / [deg] Coordinate increment at reference point
CDELT2  =      336.88692248353 / [m s-1] Coordinate increment at reference point
CUNIT1  = 'deg'                / Units of coordinate increment and value
CUNIT2  = 'm s-1'              / Units of coordinate increment and value
CTYPE1  = 'RA'                 / Coordinate type codeundefined projection
CTYPE2  = 'VRAD'               / Radio velocity (linear)
CRVAL1  =       261.6775833333 / [deg] Coordinate value at reference point
CRVAL2  =      -42328.01591376 / [m s-1] Coordinate value at reference point
LONPOLE =                180.0 / [deg] Native longitude of celestial pole
LATPOLE =     -36.155694070182 / [deg] Native latitude of celestial pole
RESTFRQ =       217238530000.0 / [Hz] Line rest frequency
MJDREF  =                  0.0 / [d] MJD of fiducial time
DATE-OBS= '2018-05-02T05:59:28.656000' / ISO-8601 time of observation
MJD-OBS =      58240.249637222 / [d] MJD of observation
OBSGEO-X=       2225142.180269 / [m] observatory X-coordinate
OBSGEO-Y=     -5440307.3703486 / [m] observatory Y-coordinate
OBSGEO-Z=     -2481029.8518735 / [m] observatory Z-coordinate
RADESYS = 'ICRS'               / Equatorial coordinate system
SPECSYS = 'LSRK'               / Reference frame of spectral coordinates
COMMENT JvM_epsilon_max=0.8076561747395334
COMMENT JvM_epsilon_min=0.7388852694815842
COMMENT JvM_epsilon_median=0.7457567637342183
COMMENT collapse_axis=1
COMMENT Original Unit=Hz
COMMENT Original Type=FREQ
END

results in a message: "Error loading file: Error loading FITS image."

The file should load, even if it can't be aligned with other data

[veggiesaurus]

@kswang1029 any ideas on this?

[kswang1029]

@veggiesaurus guess it is the axes parser at the backend unable to recognize it is a PV image. We might need to adjust the frontend too (ast grid).

[kswang1029]

@keflavich please confirm if this is still an issue with v4-stable which should support a rotated cube.