The real author:
LeMan
KPrmSt is a stochastic drawn on the basis of “pseudo-weekly” bars.
The indicator uses SmoothAlgorithms.mqh library classes (must be copied to the terminal_data_folder\MQL5\Include). The use of the classes was thoroughly described in the article “Averaging price series for intermediate calculations without using additional buffers”.
This indicator was first implemented in MQL4 and published in CodeBase on 23.04.2010.
Fig.1 The Cynthia Case stochastic.