finding p-value in pearson correlation in R Is it possible to find the p-value in pearson correlation in R?
To find the pearson correlation, I usually do this
col1 = c(1,2,3,4)
col2 = c(1,4,3,5)
cor(col1,col2)
# [1] 0.8315218

But how I can find the p-value of this?
 A: The following will do as you ask:
 library(Hmisc) # You need to download it first.
 rcorr(x, type="pearson") # type can be pearson or spearman

Here x is a data frame, and rcorr returns every correlation which it is possible to form from the "x" data frame.
Or you could calculate the statistic yourself:
$$
t = \frac{\hat{\rho}}{\sqrt{\frac{1-\hat{\rho}^2}{n-2}}}
$$
Where $\hat{\rho}$ is the pearson correlation estimated from the data, and n is the sample size.
A: you can use cor.test : 
col1 = c(1,2,3,4) 
col2 = c(1,4,3,5)
cor.test(col1,col2) 

which gives :
# Pearson's product-moment correlation   
# data:  col1 and col2   
# t = 2.117, df = 2, p-value = 0.1685   
# alternative hypothesis: true correlation is not equal to 0   
# 95 percent confidence interval:   
#  -0.6451325  0.9963561   
# sample estimates:   
#       cor    
# 0.8315218    

More information about the statistics and extra parameters at the official page: 
https://stat.ethz.ch/R-manual/R-patched/library/stats/html/cor.test.html
A: If you want only the P value: 
> cor.test(col1,col2)$p.value
[1] 0.1684782

