lib5c.plotters.asymmetric_colormap module

Module providing a function to create shifted colormaps.

lib5c.plotters.asymmetric_colormap.shifted_colormap(cmap, start=0, midpoint=0.5, stop=1.0, name='shiftedcmap')[source]

Function to offset the “center” of a colormap. Useful for data with a negative min and positive max and you want the middle of the colormap’s dynamic range to be at zero

Parameters

  • cmap (matplotlib colormap) – The matplotlib colormap to be altered

  • start (Optional[float]) – Offset from lowest point in the colormap’s range. Defaults to 0.0 (no lower ofset). Should be between 0.0 and midpoint.

  • midpoint (Optional[float]) – The new center of the colormap. Defaults to 0.5 (no shift). Should be between 0.0 and 1.0. In general, this should be 1 - vmax/(vmax + abs(vmin)). For example if your data range from -15.0 to +5.0 and you want the center of the colormap at 0.0, midpoint should be set to 1 - 5/(5 + 15)) or 0.75

  • stop (Optional[float]) – Offset from highest point in the colormap’s range. Defaults to 1.0 (no upper ofset). Should be between midpoint and 1.0.

  • name (Optional[str]) – The name under which to register the new colormap.