convert logical values to numeric values

Hi Everyone,

Really simple question but I'm struggling converting a logical array from an ischange function to a double matix. I've written the following code just to show the issue I am having. How do I convert the b to a double matrix?

Thanks!

a=[1 1 5 1 1]
b = ischange(a)
c = cell2mat(b)

Answer 1

[Jan]

a = [1 1 5 1 1]
b = ischange(a)
c = double(b)

% Alternative:
d = b + 0    % Addition with DOUBLE converts to double

cell2mat needs a cell array as input, but here are no cells.

[William Gray]

That's great, thanks!

Answer 2

[Steven Lord]

What do you want the double array to represent?

• Just 0 and 1 instead on false and true? Use Jan's approach.
• 0 where there isn't a change point, the value of the original signal where there is? Use .* to multiply the original signal and the logical vector.
• The indices where the change points occur in the original signal? You can use find for this, but if you're planning to use this for indexing (to get just the change point value) you can use the logical array returned by ischange to perform logical indexing.
• Something else, in which case please explain what you want to do in more detail.

[William Gray]

just a 0 for no change, a 1 where there is a change point so Jan's approach worked, but thank you for this, also very useful!