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rstatisticspermutationanalysis

What's wrong with this code with permtest function in R?

    ID pounds Drug
1   1   46.4    B
2   2   40.4    A
3   3   27.6    B
4   4   93.2    B
5   5   28.8    A
6   6   36.0    A
7   7   81.2    B
8   8   14.4    B
9   9  64.0    A
10 10   29.6    A

My code is

test <-permtest(data1$pounds[Drug=='A'],data1$pounds[Drug=='B'])

But I get an error saying object 'Drug' not found. Help!

Solution

  • We need to extract the column with $ or [[. Here it is searching for an object 'Drug' in the global env, which is not created there, but only within the environment of the 'data1'. So, either use $/[[

    permtest(data1$pounds[data1$Drug=='A'],data1$pounds[data1$Drug=='B'])

    Or use with

    with(data1, permtest(pounds[Drug == 'A'], pounds[Drug == 'B']))