Swerling 1.rar_Swerling目标_fluctuating target_roc curves_swerling

function [value] = incomplete_gamma ( vt, np) % This function implements Eq. (2.67) to compute the Incomplete Gamma function % This function needs "factor.m" to run format long eps = 1.000000001; % Test to see if np = 1 if (np == 1) value1 = vt * exp(-vt); value = 1.0 - exp(-vt); return end sumold = 1.0; sumnew =1.0; calc1 = 1.0; calc2 = np; xx = np * log(vt+0.0000000001) - vt - factor(calc2); temp1 = exp(xx); temp2 = np / (vt+0.0000000001); diff = .0; ratio = 1000.0; if (vt >= np) while (ratio >= eps) diff = diff + 1.0; calc1 = calc1 * (calc2 - diff) / vt ; sumnew = sumold + calc1; ratio = sumnew / sumold; sumold = sumnew; end value = 1.0 - temp1 * sumnew * temp2; return else diff = 0.; sumold = 1.; ratio = 1000.; calc1 = 1.; while(ratio >= eps) diff = diff + 1.0; calc1 = calc1 * vt / (calc2 + diff); sumnew = sumold + calc1; ratio = sumnew / sumold; sumold = sumnew; end value = temp1 * sumnew; end