determining order of accuracy

I've been given a table of discretion size and relative error and asked to determine the order of accuracy. I am new to Matlab and I am unsure how to tell matlab how to calculate this

h = 0.2 0.1 0.05 0.025 
e = 6.98e-8 1.4e-9 2.5e-11 4.2e-13

Answer 1

[J. Alex Lee]

This is not a matlab question but a numerical analysis problem. Since someone already generated the results for you, it's a matter of understanding that typical discretization errors scale with the discretization size raised to some power, which is the order of accuracy

where h is the discretization size, so

So within a shift, you can find the order of accuracy p

h = [0.2 0.1 0.05 0.025 ]
e = [6.98e-8 1.4e-9 2.5e-11 4.2e-13]


pfit = polyfit(log(h),log(e),1)

p = pfit(1)