question: private double allowableError ( int rank ) { int size = samples . size ( ) ; final double error = calculateError ( rank , size ) ; final double minError = size + 1 ; if ( error < minError ) { return error ; } return minError ; }
target:  Specifies the allowable error for this rank, depending on which quantiles are being targeted. <p> This is the f(r_i, n) function from the CKMS paper. It's basically how wide the range of this rank can be.