MATLAB: Problem to find the index in 999×6 double

arrayfindMATLAB

Hi, D = 999×6 double, I tried to use the function find to locate 0.5 values index in first two columns separately(x=999×1 double and y=999×1 double) but after several methods of trying I got same answers that are 1×0 empty double row vector and 0×1 empty double column vector. Please guide me to find the decimals 0.5001 values in the long vector. Thank you
Best regards, Venkat

Best Answer

You define a small tolerance value and find the difference less then this tolerance. This is the way to find flottant points.
tol=10^-6;
idx=find(abs(col-0.5001)<=tol);