Using ismember with cell arays, R2010

Hi,

I have a matrix containing both letters and values. Example down below, very similar to the real one i used below. I have a nother vector saved as

M_Punkter = {'B76', 'B80', 'B83'};

My code for evaluating these is:

VAL=1

for i=1:length(M_Punkter)

Lia = ismember(raw{1,1}(:,1),M_Punkter(i));

VAL=VAL+1;

end

I get the error message

??? Error using ==> cell.ismember at 28

Input must be cell arrays of strings.

Error in ==> Bulleranalys_V3_ej_fin at 77

Lia = ismember(raw{1,1}(:,1),M_Punkter(i));

Note, it is not finished. Just testing phase to get the basics right

I understand that I have made something fundamentally wrong and read up on https://se.mathworks.com/help/matlab/ref/double.ismember.html

where they used cell arays. My raw file contains multilevel cell arays. And my results from raw{1,1}(:,1)

ans =

'Mätpunkt'

[NaN]

'B76'

'B76'

'B76'

'B76'

'B76'

'B76'

'B76'

'B76'

'B76'

[NaN]

[NaN]

[NaN]

and

M_Punkter(i)

ans =

'B76'

I used the example in https://se.mathworks.com/help/matlab/ref/double.ismember.html

A = {'dog','cat','fish','horse'};

Create a cell array of character vectors, B, where some of the vectors have trailing white space.

B = {'dog ','cat','fish ','horse'};

Determine which character vectors of A are also in B.

[Lia,Locb] = ismember(A,B)

Lia = 1x4 logical array

0 1 0 1

Locb = 1×4

0 2 0 4

What key detail have I missed?

Answer 1

[Steven Lord]

What key detail have I missed?

The fact that your raw cell array contains both text and numbers.

groceries = {'apple', 'banana', 'chicken', 'milk'};
fruit = {'apple', 'banana'};
ismember(groceries, fruit)

ans = 1x4 logical array
   1   1   0   0

Compare the above with:

groceries = {'apple', 'banana', 'chicken', 'milk', 23.55};
fruit = {'apple', 'banana'};
ismember(groceries, fruit)

Error using cell/ismember (line 34)
Input A of class cell and input B of class cell must be cell arrays of character vectors, unless one is a character vector.

This is a different error message than you would receive if you ran this code in release R2010a or R2010b (we've changed it at least once in the ensuing ten years) but the root cause is the same. If you run the second example you'll see it gives you the same error as you posted.

[Erik From]

Okay, thank you. After looking at it for a long time it seemed that the NaN numbers were in some way a problem.

Lia = ismember(raw{1,1}(:,1),M_Punkter(i)); the goal is to only compare letters.

So making a command to remove all NaN would be an approach.

Just out of interest. Is there any other command that can handle both letters and vectors for the same intended purpose as ismember? As the error message suggest, would it be char?