Error in shapiro.test : sample size must be between

r normal-distribution
Peter Pfand picture Peter Pfand · Jan 29, 2015 · Viewed 19k times · Source

I have a vector, in R, with 1521298 points, which have to be tested for normality. I chose the Shapiro-Wilk test, but the R function shapiro.test() says:

Error in shapiro.test(z_scores) : sample size must be between 3 and 5000

Do you know any other function to test it or how to circumvent this issue?

Answer

Wagner Cipriano picture Wagner Cipriano · Nov 30, 2017

Shapiro test cannot done using more than 5.000 records.

You can try to do the shapiro test using only the first 5.000 samples. IF it can help you, use the code like this:

shapiro.test(beaver2$temp[0:5000])

But pay attention, the test will use only the first 5.000 samples of your data.

In the other hand, if you need to use all the records of your sample, use another similar test, like Anderson-Darling normality test. You also can execute both and compare, like this script below:

# clean workspace
rm(list=ls())

# Install required packages:
install.packages('nortest')

#Model data tho use
ModelData = beaver2$temp

#Do shapiro test with only the first 5000 records
shapiro.test(ModelData[0:5000])$p.value

#Anderson-Darling normality test
library(nortest)
ad.test(ModelData)$p.value

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