search for: pspearman

...110 onwards are shown): ## Use the test statistic S = sum(rank(x) - rank(y))^2 ## and AS 89 for obtaining better p-values than via the ## simple normal approximation. ## In the case of no ties, S = (1-rho) * (n^3-n)/6. pspearman <- function(q, n, lower.tail = TRUE) { if(n <= 1290) # n*(n^2 - 1) does not overflow .C("prho", as.integer(n), as.double(q + 1), p = double(1),...

...> > ## Use the test statistic S = sum(rank(x) - rank(y))^2 > ## and AS 89 for obtaining better p-values than via the > ## simple normal approximation. > ## In the case of no ties, S = (1-rho) * (n^3-n)/6. > pspearman <- function(q, n, lower.tail = TRUE) { > if(n <= 1290) # n*(n^2 - 1) does not overflow > .C("prho", > as.integer(n), > as.double(q + 1), > p = doubl...

Hi, Is there a limit on the number of observations for using cor.test. For example, > library(ctest) > cor.test(rnorm(3000), rnorm(3000), method="spearman") Error in if (q > (n^3 - n)/6) pspearman(q - 1, n, lower.tail = FALSE) else pspearman(q, : missing value where logical needed In addition: Warning message: NAs introduced by coercion I mainly want to calculate the spearman correlation rho for a data with missing values. But the rcorr function in Hmisc library (from Hmisc_1.4....

...n1: I am trying to correlate two vectors of numbers (two columns of microarray signal values) by using the non-parametric Spearman's rank correlation coefficient rho: > cor.test(V2.Signal,V3.Signal,method="spearman") but I get the error message: Error in if (q > (n^3 - n)/6) pspearman(q - 1, n, lower.tail = FALSE) else pspearman(q, : missing value where logical needed In addition: Warning message: NAs introduced by coercion I have tried to use the parametric Pearson correlation and the non-parametric Kendall's tau correlation and had no problem with that!! >...

...} else { ## Use the test statistic S = sum(rank(x) - rank(y))^2 ## and AS 89 for obtaining better p-values than via the ## simple normal approximation. ## In the case of no ties, S = (1-rho) * (n^3-n)/6. pspearman <- function(q, n, lower.tail = TRUE) { if(n <= 1290) # n*(n^2 - 1) does not overflow .C("prho", as.integer(n), as.double(q + 1), p = double(1),...

...5.2, 60.1) > y <- c( 2.6, 3.1, 2.5, 5.0, 3.6, 4.0, 5.2, 2.8, 3.8) > cor.test(x,y,method="spearman") Spearman's rank correlation rho data: x and y S = 48, p-value = 0.0968 alternative hypothesis: true rho is not equal to 0 sample estimates: rho 0.6 > 2*(1-pSpearman(.6,9)) [1] 0.08572531 Drew Hoysak

Full_Name: David Simcha Version: 2.10 OS: Windows XP Home Submission from: (NULL) (173.3.208.5) > a <- c(1:10) > b <- c(1:10) > cor.test(a, b, method = "spearman", alternative = "greater", exact = TRUE) Spearman's rank correlation rho data: a and b S = 0, p-value < 2.2e-16 alternative hypothesis: true rho is greater than 0 sample estimates:

Dear colleagues, I teach statistics using SPSS. I want to use R instead. I hit on one problem and I need some quick advice. When I want to work with ordinal variables, in SPSS I can compute the median or create a barchart or compute a spearman correlation with no problems. In R, if I "read" the ordinal variable as numeric, then I cannot do a barplot because I miss the category names. If

Dear R developers: There is a possible bug in calculating the p-value for Spearman's rank correlation. Line 155 in file R-patched/src/library/stats/R/cor.test.R is as.double(round(q) + lower.tail), I think, it should be as.double(round(q) + 2*lower.tail), The reason is that round(q) is expected to be an even number (the S statistic), so the next feasible value is round(q)+2.

...9 in the example above, one can use cor.test(x, -y, method="spearman", alternative="less")$p.value # 0.03036413 since on the side of negative correlation, R calls AS 89 correctly. So, for the x, y above, correctly called AS 89 has absolute error 0.00008135. There is a package pspearman currently included to CRAN, which provides a correction of the problem without the need to modify R base. Petr.

...lopment version R version 2.9.0 Under development (unstable) (2009-03-03 r48046) is as follows. --- R-devel/src/library/stats/R/cor.test.R 2008-12-14 17:51:56.000000000 +0100 +++ R-cor.test/src/library/stats/R/cor.test.R 2009-03-05 10:39:07.383841736 +0100 @@ -151,9 +151,9 @@ pspearman <- function(q, n, lower.tail = TRUE) { if(n <= 1290 && exact) # n*(n^2 - 1) does not overflow .C("prho", as.integer(n), - as.double(round(q) + lower.tail), +...