function [Var, datastack, List] = exclude_by_std(datastack, variable, r)
% This function excludes values of a variable that are more than r standard deviations
% away from the mean. Makes a new datastack excluding those epochs which
% correspond to the excluded variable indices. Also makes a list of those
% indices.
Mean = mean(variable);
Std = std(variable);
Max = Mean + r*Std;
Min = Mean - r*Std;
Var = variable;
List = zeros(length(Var(:,1)),1);
m = 1;
for i = length(variable(:,1)):-1:1
    if ((Var(i,1) > Max) || (Var(i,1) < Min))
        Var(i,:) = [];
        List(m,1) = i;
        m = m+1;
        datastack(:,:,i) = []; 
    end
end
for i = length(variable(:,1)):-1:1
    if List(i,1) == 0
        List(i,:) = [];
    end
end
end