Remove elements in a vector that are greater than value

Question

I need to remove elements (that I am plotting with error bars, so I need to remove that data point from all four vectors below) where the diff vector is greater

Answer 1

Don't use a for loop. Do something like this if you want to replace certain values by NA:

Z[diff >= 2*std] = NA

Alternatively, if you want to just filter out the rows that don't satisfy the condition, subset only the rows you want:

Z <- Z[diff < 2*std]