Calling text file in matlab

if i have text file that has three column say

                                           1 2 1
                                           3 1 1
                                           2 3 1

and also have a matrix s =

                    [0.3  0.4   0.6
                     0.1  0.5  0.7
                     0.2  0.11  0.9]

firstly: with respect to text file, i want to consider first column as i and second column as j then if the third column equal 1 then put its corresponding value in matrix s in new array say A else put remaining value in matrix s in new another array say B.

i.e i want this result

A=[0.4, 0.2, 0.7] B=[0.3, 0.6, 0.1, 0.5, 0.11, 0.9]

[Guillaume]

Where do the values go if the third column is not 1? At present your rule is:

coordinate is present and third column is 1 -> put in A
coordinate not present -> put in B

what is the rule for

coordinate is present and third column is not 1 -> ??

[muhammad ismat]

i'm so sorry for more questions

we consider the coordinates that present are 1 2, 2 1,3 1, 1 3,2 3,3 2; i.e that present and its inverse so A=[0.4 , 0.1 , 0.2 , 0.6 , 0.7, 0.11] B=[0.3, 0.5, 0.9]

2- how to take percentage of variable A say 20% of values

Answer 1

[Andrei Bobrov]

ii = [1 2 1
3 1 1
2 3 1];
s = [0.3  0.4   0.6
0.1  0.5  0.7
0.2  0.11  0.9];

[x,y,z] = size(s);
ij = num2cell(ii,1);
idx = sub2ind([x,y,z],ij{:});

A = s(idx);
B = s(setdiff(1:numel(s),idx));

[muhammad ismat]

Thank you very much Mr. Andrei Bobrov

Answer 2

[Guillaume]

I'll assume you know how to read the text file (use load). One way to do it:

coordinates = [1 2 1
               3 1 1
               2 3 1];
s =  [0.3  0.4   0.6
      0.1  0.5   0.7
      0.2  0.11  0.9];

linindices = sub2ind(size(s), coordinates(:, 1), coordinates(:, 2))';
A = s(linindices)
B = s(setdiff(1:numel(s), linindices))

[muhammad ismat]

Thank you very much Mr. Guillaume

Answer 3

[Walter Roberson]

dlmread() or load() the text file into a matrix, and then work with it in memory.

[muhammad ismat]

Thank you , Mr Walter