How to change a cell array into vector in matlab?

Question

I have a cell array which each cell is a point on (x,y) coordination (i.e, the cells are of size [1x2]). Is it possible to change it to matrix that those coordination points to be reserved?

Because when I used cell2mat, the peculiar coordination was change to the size of [1x1] while I need the coordinates.

my cell array is like this: [0,2] [0,2] [1,3] [-13,10] [1,4] [-1,5]

How I can change it to a vector that these coordinates can be used later for plotting?

Solution 1

>> myCell = {[1 2],[3 4],[5 6]}; %// example cell. Can have any size/shape
>> result = cell2mat(myCell(:)) %// linearize and then convert to matrix
result =
     1     2
     3     4
     5     6

To plot:

plot(result(:,1),result(:,2),'o') %// or change line spec

Solution 2

Another way to accomplish this:

c = {[1 2], [3 4], [5 6]};
v = vertcat(c{:});    % same as: cat(1,c{:})

plot(v(:,1), v(:,2), 'o')

Cell arrays in MATLAB can be expanded into a comma-separated list, so the above call is equivalent to: vertcat(c{1}, c{2}, c{3})

Comments

[Biju]

thanks Luis, but I want to plot these coordinates of [x y], while they are in cell format and don't need to get them seperated

[Luis Mendo]

In your question you say "change it to matrix"... Anyway, see updated answer

[Muhammad Usman Saleem]

@LuisMendo what about myCell = {[1 2 3],[3 4 ],[5 6 5 6 7]} then how can i convert this cell array to vector?

[Muhammad Usman Saleem]

what about c= {[1 2 3],[3 4 ],[5 6 5 6 7]} then how can i convert this cell array to vector?

[Amro]

in your case, you can only flatten the cell array into a one-dimensional vector (1x10 vector) as v = [c{:}] or v = cat(2, c{:}). You see when concatenating arrays, the dimensions must be consistent; you can't have a "jagged" matrix

[Amro]

otherwise you can pad each cell with NaNs so that all rows have the same length before concatenation. You can find plenty of similar questions here on Stack Overflow, for example this one: stackoverflow.com/q/3054437/97160