I have to output results (z1 and z2) so the minimum value in Z1 I want to find the value in the same index in Z2, they are 4 rows and 9 columns.

%the output of the code are 2 tables z1 and z2, each consists of 4 rows and 9 coloumns, so if the the minimum value in z1 coloumn 1 is 0.2, for the same index in z2 i want to show the value. 
x1 = [-56.6 -66.4 -70.8 -69.8 -71 -74.6 -74 -74.4 -73.2];
y1 = [-59.2 -68 -74.4 -71.4 -74.4 -73 -73.2 -74.6 -77];
for w=1:length(x1(:,1))
    for k = 1:length(x1(w,:))
        for l=1:length(y1(w,:))
            dif(l,k) = abs(x1(k) - y1(l));
        end
    end 
    [M1,I1]=min(dif(:,:));
end
x2 = [-74 -65.8 -61 -75.4 -73.6 -70.6 -80 -74.8 -72.8];
y2 = [-74.8 -70.8 -57 -73.4 -73 -70.6 -80 -76 -75.8];
for w=1:length(x2(:,1))
    for k = 1:length(x2(w,:))
        for l=1:length(y2(w,:))
            dif(l,k) = abs(x2(k) - y2(l));
        end
    end
    [M2,I2]=min(dif(:,:));
end
x3 = [-73.4 -75.6 -72.8 -70.8 -72.4 -75.2 -62.4 -69.4 -75.4];
y3 = [-78.4 -76.6 -75.2 -70.6 -71.2 -76.8 -62.8 -70 -75.2];
for w=1:length(x3(:,1))
    for k = 1:length(x3(w,:))
        for l=1:length(y3(w,:))
            dif(l,k) = abs(x3(k) - y3(l));
        end
    end 
    [M3,I3]=min(dif(:,:));
end
x4 = [-74.8 -76.4 -75 -74.6 -73.2 -72.4 -74.8 -71.4 -62.8];
y4 = [-76.4 -77.2 -78.2 -74.6 -74.8 -71.2 -73.4 -64.6 -61.4];
for w=1:length(x4(:,1))
    for k = 1:length(x4(w,:))
        for l=1:length(y4(w,:))
            dif(l,k) = abs(x4(k) - y4(l));
        end
    end 
    [M4,I4]=min(dif(:,:));
end
z1 = [M1;M2;M3;M4]

z1 = 4×9

2.6000 1.6000 0.6000 1.6000 0.4000 0 0.4000 0 0 0.6000 4.8000 4.0000 0.4000 0.2000 0 0 0 0.2000 1.8000 0.4000 1.6000 0.2000 1.2000 0 0.4000 0.6000 0.2000 0 0 0.2000 0 0.2000 1.0000 0 0.2000 1.4000

z2 = [I1;I2;I3;I4]

z2 = 4×9

1 2 4 4 4 8 3 3 7 4 6 3 9 4 6 7 1 5 3 3 5 4 5 3 7 8 3 5 1 5 4 7 7 5 6 9

[Torsten]

Others in the forum might understand what you want - I don't.

Could you give a small example ?

[Sarah Bassiouny]

in z1 for the first coloumn the smallest value is zero, so for the same index in z2 the value is 5, so that is the value i want to display. for coloumn 2 the value i want to display is 1, based on the minumum value in z1 for that coloumn.

Hope i made it clearer.

Answer 1

[Voss]

% two matrices with the same size:
Matrix1 = magic(5)

Matrix1 = 5×5

17 24 1 8 15 23 5 7 14 16 4 6 13 20 22 10 12 19 21 3 11 18 25 2 9

Matrix2 = randi(50,[5 5])

Matrix2 = 5×5

27 10 20 47 45 18 35 33 17 6 43 29 37 9 26 15 2 17 49 11 38 19 3 34 50

% find the index of the minimum element in each column of Matrix1:
[~,idx] = min(Matrix1,[],1)

idx = 1×5

3 2 1 5 4

% show the values of the corresponding elements in Matrix2:
[nrow,ncol] = size(Matrix2);
Matrix2(sub2ind([nrow ncol],idx,1:ncol))

ans = 1×5

43 35 20 34 11

[Sarah Bassiouny]

thank you so much, another question if i have a repeated number in the first matrix how could i display it as well.

[Voss]

Here's how it might be if you're stil only interested in the minimum of each column (i.e., if the minimum value is repeated you want to see all corresponding elements in the second matrix, but if a non-minumum value is repeated, you don't care):

% two matrices with the same size:
Matrix1 = magic(5);
% Matrix1 has some repeats:
Matrix1(1,1) = 4; % minimum of column 1
Matrix1(5,2) = 12;% non-minimum in column 2
Matrix1(3,4) = 2  % miniumum of column 4

Matrix1 = 5×5

4 24 1 8 15 23 5 7 14 16 4 6 13 2 22 10 12 19 21 3 11 12 25 2 9

Matrix2 = randi(50,[5 5])

Matrix2 = 5×5

33 8 5 45 14 31 47 37 3 47 5 42 6 9 37 14 43 45 33 9 30 28 1 26 32

% find the value of the minimum element in each column of Matrix1:
min_val = min(Matrix1,[],1)

min_val = 1×5

4 5 1 2 3

% show the values of the corresponding elements in Matrix2:
[nrow,ncol] = size(Matrix2);
for ii = 1:ncol
    Matrix2(Matrix1(:,ii) == min_val(ii),ii)
end

ans = 2×1

33 5

ans = 47

ans = 5

ans = 2×1

9 26

ans = 9

[Sarah Bassiouny]

Yesss that is exactly what i want thank you so muchh!!!

[Voss]

You're welcome!

Answer 2

[Torsten]

%the output of the code are 2 tables z1 and z2, each consists of 4 rows and 9 coloumns, so if the the minimum value in z1 coloumn 1 is 0.2, for the same index in z2 i want to show the value. 
x1 = [-56.6 -66.4 -70.8 -69.8 -71 -74.6 -74 -74.4 -73.2];
y1 = [-59.2 -68 -74.4 -71.4 -74.4 -73 -73.2 -74.6 -77];
for w=1:length(x1(:,1))
    for k = 1:length(x1(w,:))
        for l=1:length(y1(w,:))
            dif(l,k) = abs(x1(k) - y1(l));
        end
    end 
    [M1,I1]=min(dif(:,:));
end
x2 = [-74 -65.8 -61 -75.4 -73.6 -70.6 -80 -74.8 -72.8];
y2 = [-74.8 -70.8 -57 -73.4 -73 -70.6 -80 -76 -75.8];
for w=1:length(x2(:,1))
    for k = 1:length(x2(w,:))
        for l=1:length(y2(w,:))
            dif(l,k) = abs(x2(k) - y2(l));
        end
    end
    [M2,I2]=min(dif(:,:));
end
x3 = [-73.4 -75.6 -72.8 -70.8 -72.4 -75.2 -62.4 -69.4 -75.4];
y3 = [-78.4 -76.6 -75.2 -70.6 -71.2 -76.8 -62.8 -70 -75.2];
for w=1:length(x3(:,1))
    for k = 1:length(x3(w,:))
        for l=1:length(y3(w,:))
            dif(l,k) = abs(x3(k) - y3(l));
        end
    end 
    [M3,I3]=min(dif(:,:));
end
x4 = [-74.8 -76.4 -75 -74.6 -73.2 -72.4 -74.8 -71.4 -62.8];
y4 = [-76.4 -77.2 -78.2 -74.6 -74.8 -71.2 -73.4 -64.6 -61.4];
for w=1:length(x4(:,1))
    for k = 1:length(x4(w,:))
        for l=1:length(y4(w,:))
            dif(l,k) = abs(x4(k) - y4(l));
        end
    end 
    [M4,I4]=min(dif(:,:));
end
z1 = [M1;M2;M3;M4]

z1 = 4×9

2.6000 1.6000 0.6000 1.6000 0.4000 0 0.4000 0 0 0.6000 4.8000 4.0000 0.4000 0.2000 0 0 0 0.2000 1.8000 0.4000 1.6000 0.2000 1.2000 0 0.4000 0.6000 0.2000 0 0 0.2000 0 0.2000 1.0000 0 0.2000 1.4000

z2 = [I1;I2;I3;I4]

z2 = 4×9

1 2 4 4 4 8 3 3 7 4 6 3 9 4 6 7 1 5 3 3 5 4 5 3 7 8 3 5 1 5 4 7 7 5 6 9

[~,I] = min(z1,[],1)

I = 1×9

4 4 4 4 2 1 2 1 1

z2_min = arrayfun(@(i)z2(I(i),i),1:size(z2,2))

z2_min = 1×9

5 1 5 4 4 8 7 3 7

[Sarah Bassiouny]

Perfect, thank you so much, just one more thing please, if i have a repeated value in z1 how could I add it.