eliminating rows in a file (rookie question)

I have the following data: one variable 'markers' containing two columns(first is sample number, second is time-stamp):

 123 2.334
 645 3.445
1234 4.246
2450 5.332
2901 6.092
3287 6.345
3991 7.764

and so forth(goes down to 170 rows)

I have another called 'corrected' which contains only the first column of the previous variable minus certain rows(erroneous data which another piece of code was used to clear up the wrong samples):

 123
 645
1234
2901
3991

How can I use the 'corrected' set of numbers to eliminate the rows in the 'markers' variable so I get:

 123 2.334
 645 3.445
1234 4.246
2901 6.092
3991 7.764

I am new to matlab, so please be nice!(also, THANK YOU!)

Answer 1

[Wayne King]

Using your example

   A = [123 2.334
   645 3.445
  1234 4.246
  2450 5.332
  2901 6.092
  3287 6.345
  3991 7.764];
  B = [ 123
   645
  1234
  2901
  3991];
  [c1,ia,iab] = intersect(A(:,1),B,'rows');
  newdata = A(ia,:);

Answer 2

[Image Analyst]

Try this:

markers = [...
  123 2.334
  645 3.445
  1234 4.246
  2450 5.332
  2901 6.092
  3287 6.345
  3991 7.764]

corrected = [
  123
  645
  1234
  2901
  3991]

% Now do the extraction:
rowsToTake = ismember(markers(:, 1), corrected)
correctedMarkers = markers(rowsToTake,:)