Distibution of frequency differences for each sub-type of RR Lyrae stars. The classification types were taken from the Sesar et al. (2017) catalogue. Green indicates the stars that have matching frequencies, blue indicates the stars that have an alias of 1 or 2 cycles/day in their Pan-STARRS frequencies, and red signifies the stars that have discrepancies between their K2 and Pan-STARRS frequencies that are not aliases. The dot-edged black columns show the number of misclassified stars within each bin.