How to find the max of a cell of a cell array

I'm having issues finding the max of TR4. It's stating that max is undefined.

for s=1:34
TR1{s}=abs((prices{1,3}{1,s}(2:end))-(prices{1,4}{1,s}(2:end)));
TR2{s}=abs((prices{1,3}{1,s}(2:end))-(prices{1,5}{1,s}(1:end-1)));
TR3{s}=abs((prices{1,5}{1,s}(1:end-1))-(prices{1,4}{1,s}(2:end)));
TR4{s}={TR1(1,s) TR2(1,s) TR3(1,s)};
TR{s}=cellfun(@max,TR4(1,s))
end

[liu James]

All I'm trying to do is extract the max number between TR1, TR2, and TR3 and create TR

[liu James]

I tried this

for s=1:34
  TR1{s}=abs((prices{1,3}{1,s}(2:end))-(prices{1,4}{1,s}(2:end)));
  TR2{s}=abs((prices{1,3}{1,s}(2:end))-(prices{1,5}{1,s}(1:end-1)));
  TR3{s}=abs((prices{1,5}{1,s}(1:end-1))-(prices{1,4}{1,s}(2:end)));
  TR{s}= max(TR1{s},TR2{s},TR3{s})
  end

then I got this error.

Error using max

MAX with two matrices to compare and a working dimension is not supported.

Error in setParam (line 74)
TR{s}= max(TR1{s},TR2{s},TR3{s})

Answer 1

[John BG]

if all cells have same base type, you can use the following

T1={1 2 3 4}
cell2mat(T1)
max(cell2mat(T1))
ans =
     4

something a bit more complicated would be to build a function like find() for cells because cells may have custom indices, the find_for_cells should map the cell first.

Do you only want to find max value or also find the matrix coordinates of max value?

If you supply the cell prices or a fragment of it I will have a look whether it would be easy to build the find_cell() function.

if you find this answer useful would you please be so kind to mark my answer as Accepted Answer?

To any other reader, please if you find this answer of any help solving your question,

please click on the thumbs-up vote link,

thanks in advance

John BG

<mailto:[e-mail] [e-mail]>

[liu James]

I believe the correct statement would be I'm trying to extract the list of Mex values for each row of T1, T2, T3.

    for s=1:34
    TR1{s}=abs((prices{1,3}{1,s}(2:end))-(prices{1,4}{1,s}(2:end)));
    TR2{s}=abs((prices{1,3}{1,s}(2:end))-(prices{1,5}{1,s}(1:end-1)));
    TR3{s}=abs((prices{1,5}{1,s}(1:end-1))-(prices{1,4}{1,s}(2:end)));
    TR4{s}={TR1(1,s) TR2(1,s) TR3(1,s)};
    TR{s}=cellfun((@max),TR4(1,s))
    end

The error that I get is this.

Error using cellfun Undefined function 'max' for input arguments of type 'cell'.

   Error using cellfun
  Undefined function 'max' for input arguments of type 'cell'.

Error in setParam (line 75)
TR{s}=cellfun((@max),TR4(1,s))

[liu James]

Can you provide an example on how to use the find function to extract the max number for each row?

Answer 2

[Walter Roberson]

The result is not well defined. You have a cell array of cell arrays each of which has an vector in it. Which maximum are you looking for?

Have you considered

TR4{s} = [TR1(1,s) TR2(1,s) TR3(1,s)];

[liu James]

I'm trying to find the max out of the three vectors for all 34 sets. If that makes sense.

Let's say:

TR4{1} = [TR1(1,1) TR2(1,1) TR3(1,1)];

=[20   25.  19]

the max of TR4(1) = 25

[Walter Roberson]

Do you want the max of each corresponding position? If so then

TR4{s} = [TR1{1,s}; TR2{1,s}; TR3{1,s}];
TR{s} = max(TR4{s});

Answer 3

[Image Analyst]

Please show the entire error message -- ALL the red text, not just a small part of it. I don't know why your max function would no longer be defined. What does this say if you type it on the command line:

>which -all max

What does it show?

[liu James]

Error using cellfun
Undefined function 'max' for input arguments of type 'cell'.

Error in setParam (line 75)
TR{s}=cellfun((@max),TR4(1,s))

[Image Analyst]

Try putting brackets around the numbers to make a numerical vector, and then assigning it to another numerical vector. There is certainly no need to store the maxima in a cell array - that's an unnecessary complication.

theMaxes(s) = max([TR1{s},TR2{s},TR3{s}])