[project] partial solution for vector strength project

projects/project_vector_strength/solution/main.m

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+% partial solution for the vector strength project
+clear
+files = dir('../data/*.mat');
+dt = 1./20000;
+vs = zeros(length(files), 1);
+for i = 1:length(files)
+    load(strcat('../data/', files(i).name))
+    eod_time = (1:length(eod)) .* dt;
+    zero_crossings = zeroCrossings(eod, eod_time);
+    while spike_times(1) <= zero_crossings(1)
+        spike_times(1) = [];
+    end
+    phases = spikeEodPhase(spike_times, zero_crossings);
+    vs(i) = vectorStrength(phases); 
+end

projects/project_vector_strength/solution/spikeEodPhase.m

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+function phi = spikeEodPhase(spike_times, eod_times)
+ phi = zeros(length(spike_times), 1);
+ period = mean(diff(eod_times));
+ for j = 1:length(spike_times)
+     t = spike_times(j);
+     phase = (t - eod_times(find(eod_times <= t, 1, 'last'))) / period * 2 * pi;
+     phi(j) = phase;
+ end
+
+

projects/project_vector_strength/solution/vectorStrength.m

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+function vs = vectorStrength(phases)
+
+vs = sqrt((mean(cos(phases)).^2) + (mean(sin(phases)).^2));

projects/project_vector_strength/solution/zeroCrossings.m

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+function xings = zeroCrossings(data, time, threshold)
+    
+if nargin == 2
+    threshold = 0;
+end
+
+shift_data = circshift(data, 1);
+
+xings = time((data >= threshold) & (shift_data < threshold));