I more than 20000 data points on a an excel file and i want to plot one column against the other. So I imported 10 data points from each column seperately and tried ploting it as a normal plot but it would not work. I kept on getting error messages like 

plot([CosAa,CosBb]);

Error, (in plot) incorrect first argument [Array(1..10, 1..1, {(1, 1) = 0.83333e-2,
 (2, 1) = 0.166666e-1, (3, 1) = 0.249999e-1, (4, 1) = 0.333332e-1,
 (5, 1) = 0.416665e-1, (6, 1...