How to iteratively delete rows of a matrix?

suppose I have a matrix P and v, both have the same number of rows.and v has only one column.

I need to write a loop which excutes the following:

if the 1st element in v < tol then remove the 1st row from P.

L=size(v,1);
%id is a vector where each element contains the position of the rows that must be deleted in P
for i=1:L
    z=v(i);
    if z<tol
        id=[id;i];
    else
        1;
    end

end

so for example if id= [1 ;50; 100]; this mean I need to remove from P the 1st, the 50th and the 100th row from P

How shall I proceed ?

Thanks

Answer 1

[David Hill]

P(v<tol,:)=[];