function [f1] = calcF1(GT, labels, frames, lim)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%Calculates the F1 score of transient detection. Considers some situations
%like if there is nothing in the ground truth, nothing detected by the
%algorithm, or if everything detected by the algorithm is not a match.
% Inputs:
%     - GT: Vector of the ground truth transient times
%     - labels: Vector of the identified transients times to test
%     - frames: Vector of frames over which to calculate the f1 score (only
%     useful if there is a specific portion of the data you want to
%     iterrogate)
%     - lim: The minimum difference between the GT and labels for which a
%     pair will be considered a hit
% Output:
%     - f1: The f1 score 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
GT = GT(ismember(GT, frames));
labels = labels(ismember(labels, frames));

%If the ground truth is empty then the f1 is meaningless and a NaN is returned
if ~isempty(GT)

    %If there are no labels it's an automatic 0
    if ~isnan(labels) 
            
        %No labels in the specified frames then it's a 0
        recall = length(find(min(abs(GT-labels')) <= lim))/length(GT);
        Prec = length(find(min(abs(GT-labels')) <= lim))/length(labels);
        if recall == 0 && Prec == 0
            f1 = 0;
        else
            f1 = (2*Prec*recall)/(Prec+recall);
        end
    else
        f1 = 0;
    end
else
    f1 = NaN;
end