# [R] Cannot calculate confidence intervals NULL

varin sacha v@r|n@@ch@ @end|ng |rom y@hoo@|r
Wed Nov 15 21:53:54 CET 2023

```R-Experts,

Here below my R code working without error message but I don't get the results I am expecting.
Here is the result I get:

[1] "All values of t are equal to 0.28611928397257 \n Cannot calculate confidence intervals"
NULL

If someone knows how to solve my problem, really appreciate.
Best,
S

#########################################################
# Difference in Spearman rho

library(boot)

x1=c(4,6,5,7,8,4,2,3,5.5,6.7,5.5,3.5,2,1,3,5,6,3.5,2.5,2,1,2,3,2,1,2,3,4,3,4)

y1=c(10,14,12.5,21,15,16,17.5,11,11.5,21,19,16,17.5,18,18.5,12,13,14,11,11,12,18,20,13,23,12,11,14,16,11)

x2=c(5,3,4,2,1,1,1,2,3,4,5,4,3,2,1,3,4.5,4.5,5.5,6,5,4,7,8,3,4,2,5,4,3)

y2=c(11,12,13,11,10,19,21,21,13,15,18,13,12,14,19,18.5,17.5,12.5,10,9,11,13,14,16,11,18,14,13,12,12)

# Function to calculate the difference in Spearman coefficients
pearson_diff <- function(data, indices) {

# Sample the data
d <- data[indices, ]

# Calculate the Spearman correlation coefficients for every sample
cor1 <- cor(x1, y1, method="spearman")
cor2 <- cor(x2, y2, method="spearman")

# Return the difference
return(cor1 - cor2)
}

# Create a data.frame with the data
data <- data.frame(x1, y1, x2, y2)

# Use the boot function to apply the bootstrap
set.seed(123) # For reproducibility
bootstrap_results <- boot(data = data, statistic = pearson_diff, R = 1000)

# Calculate all the 95% confidence interval
boot.ci(bootstrap_results, type = "all")
###############################################################

```