Matt Pitkin questions

Matt Pitkin answers

• Python astropy: convert velocities from ECEF to J2000 coordinate system
• How to plot x-axis in scientific notation but only mutiples of 3?
• Position an axis at a point location
• Plot a FITS image over a grid of the entire sky
• How to multiply several vectors by one matrix at once (in numpy)?
• Why my np.gradient calculation in R^2 doesn't fit with the analytical gradient calculation?
• Using SCons as a build engine for distutils
• Create IPython notebooks with some cells already populated