Finding min values of third column for rows with similar values

Hi,

I have a Table

2.0000 0 3.1971

1.0000 0 3.1971

3.0000 0 6.4662

1.0000 0 6.4662

3.0000 0 9.6356

2.0000 0 9.6356

2.0000 1 7

1.0000 1 5

3.0000 1 6

1.0000 1 10

3.0000 1 44

2.0000 1 12

Now, what I want is that find minimum value of third column for the first column with equal value in each loop of second column.

Maybe it is better to see the result what I mean.

2.0000 0 3.1971

1.0000 0 3.1971

3.0000 0 6.4662

2.0000 1 7

1.0000 1 5

3.0000 1 6

Really appreciate

[Stephen23]

The example is not clear for me. You wrote that you want the "...minimum value of third column...", can you please explain why your example output contains this row:

...
    2.0000         1    7
...

when the input matrix contains both of these rows

...
    2.00000    1.00000    7.00000
...
    2.00000    1.00000    2.00000

As far as I can tell, 2 is less than 7, so why does the expected output not contain the "minimum value" ?

Answer 1

[Stephen23]

>> M = [2.0000,0,3.1971;1.0000,0,3.1971;3.0000,0,6.4662;1.0000,0,6.4662;3.0000,0,9.6356;2.0000,0,9.6356;2.0000,1,7;1.0000,1,5;3.0000,1,6;1.0000,1,10;3.0000,1,44;2.0000,1,2]
M =
    2.0000         0    3.1971
    1.0000         0    3.1971
    3.0000         0    6.4662
    1.0000         0    6.4662
    3.0000         0    9.6356
    2.0000         0    9.6356
    2.0000    1.0000    7.0000
    1.0000    1.0000    5.0000
    3.0000    1.0000    6.0000
    1.0000    1.0000   10.0000
    3.0000    1.0000   44.0000
    2.0000    1.0000    2.0000
>> [U,X,Y] = unique(M(:,1:2),'stable','rows');
>> V = accumarray(Y,M(:,3),size(X),@min);
>> A = [U,V]
A =
    2.0000         0    3.1971
    1.0000         0    3.1971
    3.0000         0    6.4662
    2.0000    1.0000    2.0000
    1.0000    1.0000    5.0000
    3.0000    1.0000    6.0000

You might need to consider using https://www.mathworks.com/help/matlab/ref/uniquetol.html

[ahmad Mohammadi]

Thats great. I spent like 5 hours to reach a very bad coding. But, you saved me

Thanks,

Answer 2

[Sudheer Bhimireddy]

If the order is not important, look at sort function.