How to down sample an imported txt file in MATLAB

I have a txt file that contains data (a 150000x3 table) and I need to downsample the data by an index of 1:20:length(time) to obtain the new vectors, however I do not know how to accomplish this procedure.

Answer 1

[Walter Roberson]

filename = 'as appropriate';
YourTable = readtable(filename);

NewTable = YourTable(1:20:height(YourTable), :);