fisherz {psych} | R Documentation |
Convert a correlation to a z score or z to r using the Fisher transformation or find the confidence intervals for a specified correlation. r2d converts a correlation to an effect size (Cohen's d) and d2r converts a d into an r.
fisherz(rho) fisherz2r(z) r.con(rho,n,p=.95,twotailed=TRUE) r2t(rho,n) r2d(rho) d2r(d)
rho |
a Pearson r |
z |
A Fisher z |
n |
Sample size for confidence intervals |
p |
Confidence interval |
twotailed |
Treat p as twotailed p |
d |
an effect size (Cohen's d) |
z value corresponding to r (fisherz) \ r corresponding to z (fisherz2r) \ lower and upper p confidence intervals (r.con) \ t with n-2 df (r2t) r corresponding to effect size d or d corresponding to r.
Maintainer: William Revelle revelle@northwestern.edu
cors <- seq(-.9,.9,.1) zs <- fisherz(cors) rs <- fisherz2r(zs) round(zs,2) n <- 30 r <- seq(0,.9,.1) rc <- matrix(r.con(r,n),ncol=2) t <- r*sqrt(n-2)/sqrt(1-r^2) p <- (1-pt(t,n-2))/2 r.rc <- data.frame(r=r,z=fisherz(r),lower=rc[,1],upper=rc[,2],t=t,p=p) round(r.rc,2)