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?

Maybe its better to ask that how I can plot a cell array while each cell is a peculiar coordinate on (x,y)? — Biju, Jan 23 '14 at 15:22
@Biju Exactly as Luis has shown, and then `plot(result(:,1),result(:,2),'*')` — Dan, Jan 23 '14 at 15:24

Luis Mendo · Accepted Answer · 2014-01-23T15:25:56.307

6

>> 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

edited Jan 23 '14 at 15:25

answered Jan 23 '14 at 15:05

Luis Mendo

110,752
13
76
147

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 – Biju Jan 23 '14 at 15:16
In your question you say "change it to matrix"... Anyway, see updated answer – Luis Mendo Jan 23 '14 at 15:25
@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 Dec 05 '17 at 04:40

Amro · Answer 2 · 2014-01-25T00:54:03.697

4

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})

edited Jan 25 '14 at 00:54

answered Jan 23 '14 at 16:21

Amro

123,847
25
243
454

what about `c= {[1 2 3],[3 4 ],[5 6 5 6 7]}` then how can i convert this cell array to vector? – Muhammad Usman Saleem Dec 05 '17 at 04:41
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"](https://en.wikipedia.org/wiki/Jagged_array) [matrix](https://en.wikipedia.org/wiki/Irregular_matrix) – Amro Dec 05 '17 at 11:43
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: https://stackoverflow.com/q/3054437/97160 – Amro Dec 05 '17 at 11:53

score 0 · Answer 3 · answered Jan 23 '14 at 15:35

0

myCell = {[0,2] [0,2] [1,3] [-13,10] [1,4] [-1,5]};
hold on;
cellfun(@(c) plot(c(1),c(2),'o'),myCell);

answered Jan 23 '14 at 15:35

Tobias

4,034
1
28
35

How to change a cell array into vector in matlab?

3 Answers3