Sum over numeric columns and report indices of column sums that lie within a specified range

I am trying to accomplish the following task in R.

(1) sum over the columns that are numeric

(2) given two numbers, tell me the column numbers and/or names of the columns whose column sums are within that range, inclusive

Example: I would like to sum the columns of the following data frame but there is unfortunately a column of characters causing apply to fail. Afterward, I would like to retrieve the column index of the columns that had sums between 655 and 855.

dat=data.frame(matrix(1:100, nrow=10), matrix(LETTERS[1:10], nrow=10))  apply(dat, 2, sum)  sum(dat[,7])  sum(dat[,9])  

https://stackoverflow.com/questions/66084399/sum-over-numeric-columns-and-report-indices-of-column-sums-that-lie-within-a-spe February 07, 2021 at 11:54AM