Cereal Chem 60:42 - 46.  |  VIEW ARTICLE
Computer Analysis and Plotting of Milling Data: HRS Wheat Cumulative Ash Curves.

D. W. Lillard, Jr. and D. M. Hertsgaard. Copyright 1983 by the American Association of Cereal Chemists, Inc. 

A computer program was developed that uses the Statistical Analysis System (SAS), a computer software package that calculates and plots cumulative ash against cumulative extraction and then draws a cumulative ash curve in two parts. The first part of the curve (up to the inflection point) was fitted by a cubic regression model and the second part by a linear regression model. Using the regression coefficients and the intersection point of the two regression curves found by Newton's method, the program produces tables listing cumulative ash versus cumulative extraction, relative milling value, regression statistics, and a plot of cumulative ash versus cumulative extraction, with a cumulative ash curve fitted by regression. The tables and plot, including titles, legends, axes, and curves, are drawn by the computer. The program has been used to analyze data from more than 75 hard red spring wheat samples milled over 14 years on pilot and commercial mills. The lowest correlation coefficient for both the cubic and linear regressions for all samples was 0.975.