August 17, 2018 Software Open Access

SHTOOLS/SHTOOLS: Version 4.3

Mark Wieczorek; MMesch; Elliott Sales de Andrade; Ilya Oshchepkov; Benda Xu; Andrew Walker

Version 4.3

New Gravity and Magnetic field classes

• Added gravity classes SHGravCoeffs, SHGravGrid, SHGravTensor and SHGeoid.
• Added magnetic field classes SHMagCoeffs, SHMagGrid, and SHMagTensor.
• Added new fortran subroutine MakeMagGradGridDH, which is analogous to MakeGravGradGridDH.
• Reorded the arguments of CilmPlusRhoHDH to be consistent with CilmPlusDH.
• The python routine MakeMagGridDH now also outputs the magnetic potential as a grid.

Better figures

• Addition of the function pyshtools.utils.figstyle(), that sets several matplotlib parameters for better figures. This function takes as optional parmeters the maximum useable width of a journal page, the relative width of the figure with respect to this value, and the screen resolution in dpi.
• Most plotting routines have optional parameters to set minor tick intervals, grids, label font size, and tick font size.
• Degree symbols are plotted on tick labels for maps.
• examples/python/Common/FigStyle.py was removed from the examples.
• Added the options vmin and vmax to the plotting methods SHCoeffs.plot_spectrum2d() in order to specify the limits of the color scale.
• Added the option to plot colorbars on SHGrid plots, along with the option to specify their orientation and a text label.
• All notebooks have been updated.

New constant subpackage

• The constant subpackage has been completely rewritten and now makes use of the astropy Constant class. This class has attributes name, value, uncertainty, unit, and reference. The naming of the constants has changed in some cases for consistency. A few constants that are not necessary were removed. Many of the constants were updated with more recent values. Constants can be used in arithmetic operations with either other Constants or with objects of the astropy class Quantity.
• Constants are organized into modules for each of the planets (Mercury, Venus, Earth, Moon, and Mars), and for convenience, these are all added to the main namespace. The fundamental constants G and mu0 from the astropy constants package were added (as taken from CODATA 2014).

Other changes

• Fixed a bug in how the random coeffcients were determined for unnormalized coeffcients in SHCoeffs.
• Optional parameter seed added to SHCoeffs.from_random() to allow for reproducibility.
• One can now specify colat instead of lat for the method SHCoeffs.expand().
• Added __repr__ methods to all pyshtools classes.
• Changed the mathematical operators of SHCoeffs such that addition and subtraction of a constant only affects the degree 0 term.
• Added the optional parameter lmax to SHCoeffs.plot_spectrum() and SHCoeffs.plot_spectrum2d().
• Fixed a bug in SHCoeffs.pad() where the attribute mask was not similarly padded.
• For mathematical operations with SHCoeffs grids, it is now required that the two class instances have the same lmax.
• Clarified the documentation of SHRotateCoef to point out that this is only valid for intrinsically real functions that are expressed in complex harmonics.
• Added the method volume() to the class SHCoeffs, that calculates the volume of the object.
• Added the attributes area and shannon to SHWindow, which provides the area of the concentration domain and the shannon number.
• Removed python installation support from Makefile: use pip instead.

Citation:

M. A. Wieczorek, M. Meschede, E. Sales de Andrade, I. Oshchepkov, B. Xu, and A. Walker (2018). SHTOOLS: Version 4.3, Zenodo, doi:10.5281/zenodo.1345510