error when assign a matrix

Hi there,

I have four data files with a name 4.dat, 5.dat, 6.dat and 7.dat respectively in a folder. After treating these data by codes, I wish to assign the data name and computed result to a nX2 matrix named "result". Here is my code:

    cd('C:\fitting\test\');
    Allname=struct2cell(dir); 
    [m,n]=size(Allname); 
    for i=3:n
    iname=Allname{1,i};

    ... ...            %treatment of data, the interesting result is named "a"

    result=zeros(n,2)  

    result(i,1:2)=[iname, a]

    end

An error of "??? Subscripted assignment dimension mismatch" appears and the output is

    result =

         0     0
         0     0
         0     0
         0     0
         0     0
         0     0
         0     0

I don't know why this can happen.

Many thanks.

Answer 1

[Jan]

The relevant information is missing in your question: In which line does the error appear? What is the type and value of a and iname?

I guess, that the problem is in the line:

result(i,1:2)=[iname, a]

If iname and a are not scalars, you cannot write them to the [1 x 2] vector on the left hand side of this assignment. Perhaps you want result to be a cell array, when you want to mix the string(!) iname and the variable a.

Answer 2

[Fei]

Thanks Jan.

a is a scalar;

iname is from

iname=Allname{1,i};

and

Allname=struct2cell(dir);

which is a cell array.

What shall I do if I want to output iname and a in the format of

4.dat a4
5.dat a5
6.dat a6
7.dat a7

where j.dat and aj stands for iname and a respectively for a particular data?

[Walter Roberson]

Initialize

result = cell(n, 2);

then in the loop,

result(i,1:2) = {iname, a};

assuming you want a cell array whose first element in a row is the file name and whose second element is the numeric value as a numeric value.

You could change it to num2str(a) if you want the second column to be a represented as a string, but still want columns.

If what you want is one row of characters, then initialize

result = cell(n,1);

and then in the loop,

result{i} = [inname, ' ', num2str(a)];

and after the loop,

result = char(result);