extract data based on specific condition

Hello,

Can someone help me. i am newbie in looping and conditioning things in programming. I had some problem in getting the data based on specific criteria or condition. For example i have 2 set of data which i call set1 and set2 which each data consists of multiple row and 4 column. For full set of data, the total number of rows for both 2 set are different and the total number is not cosistent between both but have the same total number of column which is 4. For example, i show some of my 2 set data.

set1:

58202.0003472222 10 12 -0.00419000000000000

58202.0003472222 12 14 0.00259000000000000

58202.0003472222 14 20 0.00437000000000000

58202.0003472222 20 21 -0.00745000000000000

58202.0003472222 21 24 -0.00101000000000000

58202.0003472222 24 25 -0.000761000000000000

58202.0003472222 25 26 0.00243000000000000

58202.0003472222 26 29 -0.00121000000000000

58202.0003472222 29 32 0.00169000000000000

58202.0006944445 10 12 -0.00427000000000000

set2:

58202.0003472222 10 12 -0.00136000000000000

58202.0003472222 12 14 0.000256000000000000

58202.0003472222 14 20 -0.000641000000000000

58202.0003472222 20 21 0.00136000000000000

58202.0003472222 21 24 -0.000655000000000000

58202.0003472222 24 25 -8.90000000000000e-05

58202.0003472222 25 29 7.69000000000000e-05

58202.0003472222 29 31 1.86000000000000e-06

58202.0003472222 31 32 -0.00101000000000000

what i want to do is i wanna take the forth (4) column for both set of data and set it as variable example a for set1 and b for set2 with a condition that the column 1, column 2, and column 3 is the same or equal.

[Sriram Tadavarty]

It would be good to indicate how the desired output should be for the provided sets, set 1 and set 2.

[Nazrin Afiq Abdul Rahman]

hello sriram,

the output should be the same as set 1 and set 2. There are 4 column and multiple row. Only data which meet the condition will be display or extract.

For example as u can see, set 1(1:6,1:3) and set2(1:6,1:3) the data was the same for both set. What i want is only the data at the column 4 which meet the condition (column1, column2 and column3 is the same for both set 1 and set 2).

Answer 1

[Matt Gaidica]

Here's an illustrative way to do it, for both the case where row order matters and does not:

set1 = [58202.0003472222,10,12,-0.00419000000000000;58202.0003472222,12,14,0.00259000000000000;58202.0003472222,14,20,0.00437000000000000;58202.0003472222,20,21,-0.00745000000000000;58202.0003472222,21,24,-0.00101000000000000;58202.0003472222,24,25,-0.000761000000000000;58202.0003472222,25,26,0.00243000000000000;58202.0003472222,26,29,-0.00121000000000000;58202.0003472222,29,32,0.00169000000000000;58202.0006944445,10,12,-0.00427000000000000];
set2 = [58202.0003472222,10,10,-0.00136000000000000;58202.0003472222,12,12,0.000256000000000000;58202.0003472222,14,14,-0.000641000000000000;58202.0003472222,20,20,0.00136000000000000;58202.0003472222,21,21,-0.000655000000000000;58202.0003472222,24,24,-8.90000000000000e-05;58202.0003472222,25,25,7.69000000000000e-05;58202.0003472222,29,29,1.86000000000000e-06;58202.0003472222,31,31,-0.00101000000000000;58202.0006944445,10,10,-0.00166000000000000;58202.0006944445,12,12,0.000414000000000000;58202.0006944445,14,14,4.67000000000000e-05;58202.0006944445,20,20,0.000736000000000000];

%% row order matters
a = [];
b = [];
% can't go past minimum row size
for ii = 1:min([size(set1,1),size(set2,1)])
    if set1(ii,1) == set2(ii,1) && set1(ii,2) == set2(ii,2) && set1(ii,3) == set2(ii,3)
        a = [a;set1(ii,4)];
        b = [b;set2(ii,4)];
    end
end

%% row order doesn't matter, compare all
a = [];
b = [];
% loop through all entires
for ii = 1:size(set1,1)
    for jj = 1:size(set2,1)
        if set1(ii,1) == set2(jj,1) && set1(ii,2) == set2(jj,2) && set1(ii,3) == set2(jj,3)
            a = [a;set1(ii,4)];
            b = [b;set2(jj,4)];
        end
    end
end

Your sample data isn't the best to try this out on, because I don't see a case that fits your condition for either method.

[Nazrin Afiq Abdul Rahman]

hello matt,

For the data, row doesnt matter. For example, the row 10 for set1 maybe was the same as the row 15 for set2. But it is true and exist for the column1, column2 and column3 to be the same for both set. I will give my example of set1 and set2 data.

As attach!

[Matt Gaidica]

Did you try the second method? I think that's what you want to do.

[Nazrin Afiq Abdul Rahman]

hello matt,

Yup. i had try both. first method the ouput was a bit less meanwhile second method takes time since it process by row on each column one by one. I try to modified the first method by adding 'find(variable)' and it looks fine. hehe. Thanks a lot matt for giving such idea :)