generate row combinations then apply a function to each row's values-CodePudding

I have a dataframe and my goal here is to take all possible combinations of the rank column and for each rank combination apply a function that will use the volume_metric and kpi_metric values. The resulting output would be a matrix just like the cor() function provides except with each rank combinations p-values.

Basically I want to take the first row values of volume_metric & kpi_metric and then the second row values of volume_metric & kpi_metric and apply the zTest function to them. Then 1->3, 1->4, etc.

rank <- c(1, 2, 3, 4, 5, 6, 7, 8)
volume_metric <- c(12321, 12321, 1232121, 4343, 14333, 52323, 234532, 2322)
kpi_metric <- c(12, 32, 111, 334, 653, 343, 232, 212)
# The df
df <- tibble(rank, volume_metric, kpi_metric)

# A tibble: 8 x 3
   rank volume_metric kpi_metric
  <dbl>         <dbl>      <dbl>
1     1         12321         12
2     2         12321         32
3     3       1232121        111
4     4          4343        334
5     5         14333        653
6     6         52323        343
7     7        234532        232
8     8          2322        212

# z-test fucntion
zTest <- function(volume1, volume2, kpi1, kpi2) {
  z_test <- prop.test(
    x=c(kpi1, kpi2),
    n=c(volume1, volume2),
    alternative = "greater",
    conf.level = 0.95,
    correct = FALSE
  )
  p_value <- z_test$p.value
  return(p_value)
}

So far I have been able to get all of the rank combinations using

possible_combinations <- combn(nrow(df), 2)

which will provide a matrix with all of the combos (the rank will always be the same as now(df)).

I tried to loop through that matrix and then subset the df but that resulted in a never ending loop