getSaccDir.m

function [saccDir, dirIndex] = getSaccDir(startSacc, endSacc, eyeData_rmotl_cat, cardinalDir)
% [saccDir, dirIndex] = getSaccDir(startSacc, endSacc, eyeData_rmotl_cat, cardinalDir)
%
% TODO: make this function faster...
%
% 19/6/23 debug a rare care where saccDir and dirIndex sizes are different

x = eyeData_rmotl_cat.x;
y = eyeData_rmotl_cat.y;
t = eyeData_rmotl_cat.t;


dirIndex = zeros(length(startSacc),1);
if isempty(startSacc)
    saccDir = [];
else
   for isacc = 1:length(startSacc)
        tsnippet = intersect(find(t>=startSacc(isacc)), find(t<=endSacc(isacc)));
        if isempty(tsnippet)
            tsnippet = find(t>=startSacc(isacc), 1 );
        end
        eyeRad = atan2(y(tsnippet)-y(tsnippet(1)), x(tsnippet)-x(tsnippet(1)));
        [~, minDirIdx] = arrayfun(@(x)(min(abs(circ_dist(x, pi/180*cardinalDir)))), eyeRad);
        dirIndex(isacc) = mode(minDirIdx);
    end
    %okIdx = (dirIndex>0);
    %dirIndex = dirIndex(okIdx);
    saccDir = cardinalDir(dirIndex);
end