wks.addcol();// add a new column
double bb=max(col(2)); 
double cc=min(col(2));

int aa = wks.ncols;
wcol(aa)=abs(col(2)-((bb+cc)/2));

limit wcol(aa); // Find min value in the new column using limit command
double dd = col(1)[$(limit.imin)]; // limit.imin -- Corresponding index for minimum Y value. 

dd=;