spearnoties {corrperm}R Documentation

Spearman Correlation and Asymptotic P-value

Description

Computes Spearman correlation and asymptotic p-value with no correction for ties. Only intended for use by cp.test.

Usage

spearnoties(x, y, alt = 1)

Arguments

x a vector of x data
y a vector of y data
alt alt specifies the sign of the correlation for the alternative hypothesis: 1 if >0 and -1 if <0

Value

a vector consisting of the p-value, the Spearman correlation and the number of pairs used in the calculation.

Author(s)

Douglas M. Potter

Examples


x<-rnorm(10)
y<-x+rnorm(10)

spearnoties(x,y)

## The function is currently defined as
function(x,y,alt=1){
#asymptotic spearman test, assumes no ties 
sel<-is.na(x-y)==F #elim NAs
d<-rank(x[sel])-rank(y[sel])
n<-length(d)
spear<-1-(6*sum(d^2))/(n^3-n)
p<-1-pnorm(spear*sqrt(n-1))
if(alt==-1)p<-1-p
#return one-sided p-value, statistic, number of comparisons
return(c(p,spear,n))
  }

[Package corrperm version 1.0 Index]