Interface for spectra, images and cubes (mpdaf.obj)

The mpdaf.obj package provides a way to load a MUSE cube created by the MUSE pipeline (i.e. a 3GB FITS data cube of approximately 300x300x3680 pixels) into a Python object that manages spatial world-coordinates, wavelength world coordinates, pixel variances and bad pixel information.

It is then relatively easy to extract smaller cubes, narrow-band images or spectra from the cube. The world coordinates, associated variances and bad-pixel masks are propagated into these extracted cubes, images, and spectra. Many useful operations like masking, interpolation, re-sampling, smoothing and profile fitting are also provided.

Contents:

• Spectrum, Image and Cube format
  • Attributes
  • Indexing
  • Getters and setters
• Operations on masks
• Arithmetic
  • Operations along one or more axes
  • Arithmetic Operations between objects
  • Generic object arithmetic:
• Rearranging
• Convolution
• Copy, clone or save
  • Copy
  • Clone
  • Save
• Spectrum object
  • Spectrum Creation
  • Spectrum masking and interpolation
  • Spectrum rebinning and resampling
  • Continuum and line fitting
• Image object
  • Image creation
  • Image Geometrical manipulation
  • Object analysis: image segmentation, peak measurement, profile fitting
• Cube object
  • Cube creation
  • Loops over all spectra
  • Loops over all images
  • Creation of images
  • Sub-cube extraction
• Cube lists and combination
  • CubeList object format
  • Examples
  • Reference
• World coordinates
  • Degree / sexagesimal conversion
  • Spatial world coordinates
  • Spectral world coordinates

Reference/API

mpdaf.obj Package

Functions

UnitArray(array, old_unit, new_unit)
UnitMaskedArray(mask_array, old_unit, new_unit)
airtovac(airwl)	Convert air wavelengths to vacuum wavelengths.
axis_increments_from_cd(cd)	Return the angular increments of pixels along the Y and X axes of an image array whose coordinates are described by a specified FITS CD matrix.
bounding_box(form, center, radii, shape[, …])	Return Y-axis and X-axis slice objects that bound a rectangular image region that just encloses either an ellipse or a rectangle, where the rectangle has a specified center position, Y-axis and X-axis radii, and a given rotation angle relative to the image axes.
deg2dms(x)	Transform degrees to degrees:arcminutes:arcseconds strings.
deg2hms(x)	Transform degrees to hours:minutes:seconds strings.
deg2sexa(x)	Transform equatorial coordinates from degrees to sexagesimal strings.
determine_refframe(phdr)	Determine the reference frame and equinox in standard FITS WCS terms.
dms2deg(x)	Transform degrees:arcminutes:arcseconds strings to degrees.
flux2mag(flux, err_flux, wave)	Convert flux from erg.s-1.cm-2.A-1 to AB mag.
gauss_image([shape, wcs, factor, gauss, …])	Create a new image from a 2D gaussian.
hms2deg(x)	Transform hours:minutes:seconds strings to degrees.
image_angle_from_cd(cd[, unit])	Return the rotation angle of the image.
is_float(x)	Test if x is a float number.
is_int(x)	Test if x is an int number.
is_number(x)	Test if x is a number.
iter_ima(cube[, index])	An iterator over the images of successive spectral pixels in a Cube
iter_spe(cube[, index])	An iterator over the spectra of successive image pixels in a Cube
mag2flux(mag, wave)	Convert flux from AB mag to erg.s-1.cm-2.A-1
moffat_image([shape, wcs, factor, moffat, …])	Create a new image from a 2D Moffat function.
plot_rgb(images[, title, scale, vmin, vmax, …])	Plot the RGB composite image with axes labeled in pixels.
sexa2deg(x)	Transform equatorial coordinates from sexagesimal strings to degrees.
vactoair(vacwl)	Calculate the approximate wavelength in air for vacuum wavelengths.

Classes

Cube([filename, hdulist, data, mask, var, …])	This class manages Cube objects, which contain images at multiple wavelengths.
CubeList(files[, scalelist, offsetlist])	Manages a list of cubes and handles the combination.
CubeMosaic(files, output_wcs, **kwargs)	Manages a list of cubes and handles the combination to make a mosaic.
DataArray([filename, hdulist, data, mask, …])	Parent class for Cube, Image and Spectrum.
Gauss1D(lpeak, peak, flux, fwhm, cont, …)	This class stores 1D Gaussian parameters.
Gauss2D(center, flux, fwhm, cont, rot, peak, …)	This class stores 2D gaussian parameters.
Image([filename, ext, wcs, data, var, unit, …])	Manage image, optionally including a variance and a bad pixel mask.
Moffat2D(center, flux, fwhm, cont, n, rot, …)	This class stores 2D moffat parameters.
SpatialFrequencyLimits(fmax, rot)	Allow to keep track of the spatial frequency limits of an image.
Spectrum([filename, hdulist, data, mask, …])	Spectrum objects contain 1D arrays of numbers, optionally accompanied by corresponding variances.
WCS([hdr, crpix, crval, cdelt, deg, rot, …])	The WCS class manages the world coordinates of the spatial axes of MPDAF images, using the pywcs package.
WaveCoord([hdr, crpix, cdelt, crval, cunit, …])	WaveCoord class manages world coordinates in spectral direction.

Class Inheritance Diagram