A computer program for fitting multimodal probability density functions.

A FORTRAN IV program is described, which may be run interactively with tutorial assistance or in batch and which allows a user to selectively fit any of seven probability density functions (p.d.f.'s) or a combination of the p.d.f.'s to a unimodal or multimodal histogram of empirical data. A "best-fit", uni- or multimodal p.d.f., which may be obtained by a method of nonlinear least squares or a generated p.d.f. may be displayed on a Tektronix 4010 terminal as a continuous curve against the background of a bar, square wave, symbol or point-plot histogram. The following, supportive statistical information is also displayed: (1) Kolmogorov-Smirnov probability of goodness of fit, (2) mean square error, (3) correlation coefficient, and (4) parameter estimates. The resident driver program and six overlayable segments have been implemented on a Digital Equipment Corporation LAB-11 minicomputer (PDP-11/20).