Matlab - for loop in anonymus function

Tarrasch picture Tarrasch · Apr 14, 2011 · Viewed 11.9k times · Source

I'm quite new to matlab, but I know how to do both for loops and anonymous functions. Now I would like to combine these.

I want to write:

sa = @(c) for i = 1:numel(biscs{c}), figure(i), imshow(biscs{c}{i}.Image), end;

But that isn't valid, since matlab seem to want newlines as only command-seperator. My code written in a clear way would be (without function header):

for i = 1:numel(biscs{c})
    figure(i)
    imshow(biscs{c}{i}.Image)
end

I look for a solution where either I can write it with an anonymous function in a single line like my first example. I would also be happy if I could create that function another way, as long as I don't need a new function m-file for i.

Answer

Jonas picture Jonas · Apr 14, 2011

Anonymous functions can contain multiple statements, but no explicit loops or if-clauses. The multiple statements are passed in a cell array, and are evaluated one after another. For example this function will open a figure and plot some data:

fun = @(i,c){figure(i),imshow(imshow(biscs{c}{i}.Image)}

This doesn't solve the problem of the loop, however. Fortunately, there is ARRAYFUN. With this, you can write your loop as follows:

sa = @(c)arrayfun(@(i){figure(i),imshow(biscs{c}{i}.Image)},...
         1:numel(biscs{c}),'uniformOutput',false)

Conveniently, this function also returns the outputs of figure and imshow, i.e. the respective handles.