How do i refer to an entire row in a matrix, while only specifying one variable in that row?

I have a matrix consisting of 2 columns and 160 rows. My aim is to automatically generate the entire row in which the second variable is the lowest of it's column. For example:

Matrix = [1 5; 4 1; 2 7; 3 8]

I need a code which generates the second row (4 1) since 1 is the lowest number in the second column. Thank you in advance for the help!

Answer 1

[dpb]

Unfortunately, here's where Matlab syntax of only being able to return and use the first argument inline hurts (albeit I don't have a suggestion for an alternate syntax) so you must use an intermediate variable...

[~,ix]=min(M(:,2));  % loc of min in 2nd column
N=M(ix,:);           % that row from M

This works reliably only if there is a unique minimum; if repeated minimums are possible the above will return only the location of the first of same...

[Jesse Saris]

Thank you, I think this will work fine.. Just changed a little thing:

[~,ix]=min(M(:,1));  % loc of min in 2nd column
N=M(ix,:);           % that row from M

to

[~,ix]=min(M(:,2));  % loc of min in 2nd column
N=M(ix,:);           % that row from M

Thank you!

[dpb]

Oh, yeah, did have a typo; will fixup answer. Please "ACCEPT" answer if it solved the issue...

[Jesse Saris]

I accepted it, thank you for the advice.. I've just started working with Matlab this month. I also have a follow-up question: Is it possible to automatically delete this minimum from the matrix and continue working with the altered matrix? I now how to clear variables, but not how to delete one row out of a matrix.

Thank you again for the help!

[dpb]

Set the desired row(s)/column(s) to empty ([]) ...

x(ix,:)=[];  % delete the rows in index vector ix

I suggest opening the online documentation and working thru the "Getting Started" exercises -- it'll walk you thru these kinds of introductory syntax exercises more quickly.

Answer 2

[matico]

Something like this:

 Matrix = [1 5; 4 1; 2 7; 3 8];

 SecCol = Matrix(:,2);
 [val,ind] = min(SecCol);

 Result = Matrix(ind,:)