No data for colormapping provided via 'c' warning
Some tests of the reduction
module give this warning:
UserWarning: No data for colormapping provided via 'c'. Parameters 'cmap' will be ignored
scat = ax.scatter(element[:,0], element[:,1], c=color, cmap=color_map, marker='o', s=scatter_point_size, edgecolor='none', alpha=1)