ztwo {clippda} | R Documentation |
This function computes the effects of covariates (Z values) needed when designing a study in simple cases where the only covariate available is the cancer class. The Z values computed may, however, be used in more complex setups, when additional covariates are expected.
ztwo(x, y)
x |
expected proportion of cases |
y |
expected proportion of controls |
produces the Z value
Stephen Nyangoma
Nyangoma SO, Ferreira JA, Collins SI, Altman DG, Johnson PJ, and Billingham LJ: Sample size calculations for planning clinical proteomic profiling studies using mass spectrometry. (Working paper)
function ZvaluescasesVcontrolsPlots
x=1/3;y=1-x ztwo(x,y)