在Apply R中引用自定义函数

Question

I have an N x 2 matrix called mat.

mat <- cbind(c(2:4), c(.5, 1, 1.5))
colnames(mat) <- c('x2', 'x3')

I created a function called calcCDF in R. This function requires 3 inputs x1, x2, and x3. x1 defaults to 100000. The actual calcCDF function is more complicated. The one shown below is just to illustrate the point.

calcCDF <- function(x1=100000, x2, x3){
cdf <- x1 + x2 * x3
return(cdf)
}

calcCDF(x2=2, x3=0.5) returns the value 100001

I would like x2 and x3 to be populated with the first and second columns of mat respectively and apply the function to each row of mat so that I get back a vector of length N.

I tried apply(mat, 1, calcCDF(x2=mat[1], x3=mat[2])) but get an error stating Error: unexpected ']'.

Answer 1

If you want to use apply() with your customised function calcCDF , this is how you can use

 apply(mat, 1, function(y) calcCDF(x2 = y[1], x3 = y[2]))

OR

 apply(mat, 1, function(x) calcCDF(x2 = x["x2"], x3 = x["x3"]))