plotting from cell array of different lengths - matlab

Question

this might come as an eco in this forum but I couldn't find a solution that I could apply to my problem. I have a cell of res_A1 of size (1x500) and in each cell there is a vector (1xlength) where length varies. I would like to plot in the same graph every vector or maybe a handful of them. All lines can be in the same color. I have tried following but the graph make no sense
data=res_A1(1,:,end);
plot(cell2mat(data)');
Also I would like to plot the average of the 500 vectors, preferably this should be in the same graph in another color. Is there a nice way of doing this?

Answer 1

You can use cat to combine the vectors along the first dimension. Then you can pass the transpose of this matrix to plot and each column will be plotted as it's own plot.
plot(cat(1, data{:}).');
If we create some example data, this will yield.
data = arrayfun(#(x)rand(1,10), ones(1, 5), 'uni', 0);
plot(cat(1, data{:}).');
If you want specific ones (i.e. [1 3 5]), you can replace : above with the indices of the ones you want.
plot(cat(1, data{[1 3 5]}).');
If you want to plot the average, simply use mean on the result of the call to cat.
avg = mean(cat(1, data{:}), 1);
plot(avg);
And if you wanted it in the same plot:
alldata = cat(1, data{:});
avg = mean(alldata, 1);
% Plot all of the curves
plot(alldata.');
hold on
% Plot the average curve
plot(avg, 'LineWidth', 3, 'Color', [0.5 0.5 0.5], 'LineStyle', '--')
Update
If your data is all different lengths, You have two options, you could plot everything with a loop.
hax = axes;
hold(hax, 'on');
for k = 1:numel(data)
plot(data{k}, 'Parent', hax);
end
Or you could still try to combine everything into one matrix, padding with NaN values.
% Find the longest vector length
maxlength = max(cellfun(#(x)numel(x), data));
alldata = nan(maxlength, numel(data));
for k = 1:numel(data)
alldata(1:numel(data{k}),k) = data{k};
end
Then you can plot this and take the mean using nanmean.
plot(alldata);
avg = nanmean(alldata, 2);