LWnomo1: Recreate Litchfield and Wilcoxon's Nomograph No. 1

Description Usage Arguments Details Value References Examples


Recreate Litchfield and Wilcoxon's (1949) nomograph to estimate the contribution to the chi-squared from the expected percent effect and the observed minus the expected percent effect.


LWnomo1(values = FALSE, ...)



A logical scalar indicating whether values should be output.


Additional parameters to par.


Use the nomograph by laying a straight edge from the expected percent effect in the first scale to the observed (corrected, if necessary) minus the expected percent effect in the second scale and reading the point where the straight edge crosses the third scale as the contribution.

The formula behind the nomograph is (observed - expected)^2 / (100 * expected)


If values is TRUE, a list of length four, with the x and y coordinates and the corresponding values (all displayed in the log10 scale) of the end points of the three scales. Information is provided twice for the first scale, once for the left tick marks and once for the right tick marks.


Litchfield, JT Jr. and F Wilcoxon. 1949. A simplified method of evaluating dose-effect experiments. Journal of Pharmacology and Experimental Therapeutics 96(2):99-113. [link].



Example output

Warning message:
no DISPLAY variable so Tk is not available 

LW1949 documentation built on May 2, 2019, 6:11 a.m.