The stochastic RSI oscillator, applies RSI values instead of price into the stochastic formula.

Stochastic RSI = ((Today’s RSI – Lowest RSI Low in %K Periods) / (Highest RSI High in %K Periods – Lowest RSI Low in %K Periods)) * 100

Stochastic RSI measures the value of RSI in relation to its High and Low range over the required period:
when a regular RSI reaches a a new Low for the period, Stochastic RSI will be at 0. When RSI records a new high for the period, Stochastic RSI will be at 100.

This indicator was made by request on forum.

//PRC_Stochastic RSI | indicator
//06.12.2016
//Nicolas @ www.prorealcode.com
//Sharing ProRealTime knowledge
//converted and adapted from Pinescript version

// -- parameters:
lengthRSI = 10 //RSI period
lengthStoch = 10 //Stochastic period
smoothK = 10 //Smooth signal of stochastic RSI
smoothD = 3 //Smooth signal of smoothed stochastic RSI

myRSI = RSI[lengthRSI](close)
MinRSI = lowest[lengthStoch](myrsi)
MaxRSI = highest[lengthStoch](myrsi)

StochRSI = (myRSI-MinRSI) / (MaxRSI-MinRSI)

K = average[smoothK](stochrsi)*100
D = average[smoothD](K)

return K as "K%", D as "D%"