如何计算R中每个数据帧变量的正值之和

Question

I have dataframe with any number of numeric variables

d <- data.frame(X1 = c(-1, -2, 0), X2 = c(10, 4, NA), X3 = c(-4, NA, NA))

How I may calculate the sum of positive values for each variable to keep them in the list, and if the variable has no positive values or all the values NA, return to this variable is 0.

Answer 1

We can use the apply and ifelse functions to iterate through each column and replace NA or negative values with 0

apply(d, 2, function(x) sum(ifelse(is.na(x) | x < 0, 0, x)))

Edit - concision

As @joel.wilson pointed out, there is a more concise way of coding the logic:

apply(d, 2, function(x) sum(x[x > 0], na.rm = TRUE))

Answer 2

library(expss)
d <- data.frame(X1 = c(-1, -2, 0), X2 = c(10, 4, NA), X3 = c(-4, NA, NA))
sum_col_if(gt(0), d)
# X1 X2 X3 
# 0 14  0