Output of chi-square as vector

Question

I use the chi-square goodness of fit test with chisq.test(). Is there a way to save the output of this function as a vector, like: test <- c(X-squared, df, p-value)?

Answer 1

The output of chisq.test is a list

x <- c(A = 20, B = 15, C = 25)

test_chi <- chisq.test(x)

str(test_chi)

List of 9
 $ statistic: Named num 2.5
  ..- attr(*, "names")= chr "X-squared"
 $ parameter: Named num 2
  ..- attr(*, "names")= chr "df"
 $ p.value  : num 0.287
 $ method   : chr "Chi-squared test for given probabilities"
 $ data.name: chr "x"
 $ observed : Named num [1:3] 20 15 25
  ..- attr(*, "names")= chr [1:3] "A" "B" "C"
 $ expected : Named num [1:3] 20 20 20
  ..- attr(*, "names")= chr [1:3] "A" "B" "C"
 $ residuals: Named num [1:3] 0 -1.12 1.12
  ..- attr(*, "names")= chr [1:3] "A" "B" "C"
 $ stdres   : Named num [1:3] 0 -1.37 1.37
  ..- attr(*, "names")= chr [1:3] "A" "B" "C"
 - attr(*, "class")= chr "htest"

We can create a vector with some elements of the list

out <- c(test_chi$statistic,test_chi$parameter,test_chi$p.value)
out
X-squared        df           
2.5000000 2.0000000 0.2865048

Another option is to use the library broom

broom::tidy(test_chi)

# A tibble: 1 x 4
  statistic p.value parameter method                                  
      <dbl>   <dbl>     <dbl> <chr>                                   
1       2.5   0.287         2 Chi-squared test for given probabilities