# Removing 'high-frequency' components from an array?

I am new to the stream of digital signal processing, and hence my doubt may seem extremely stupid, but: In tools such as matlab, signals are stored in a single array. If i convolute it with an LPF array, i get another array/signal, that has certain elements attenuated, can i find out which elements these are and completely remove them from the new array.

Does my question even make sense? :/

You mention convolution which implies that your arrays represent time domain signals. As this is digital signal processing, the time is discretized and every element of the array corresponds to a sample. Two consecutive samples have a fixed time distance, say $T$.