Could someone please explain how to use the differences, especially with vectors? I would like to make a chart of the values of the four differences types, along with the corresponding x value. Say x=[0:0.2:0.6], y=sin(x), and yperfect=cos(x), how would I go about this?
UPDATE: This is the code I have to take the forward difference (first order).
function [out] = forwarddiff(x,y) n=1; L=length(x); while n < L out(n,1)=x(n); out(n,2)=(y(n+1)-y(n))/(x(n+1)-x(n)); n=n+1; endout(L,1)=x(L);out(L,2)=NaN;end
X and Y values can be input by the user. My new question is: Would the second order forward difference look something like this?
function [out] = forwarddiff(x,y) n=1; L=length(x); while n < L out(n,1)=x(n); out(n,2)=(y(n+2)-2*y(n+1)+y(n))/(x(n+1)-x(n))^2; n=n+1; end out(L,1)=x(L); out(L,2)=NaN; end
I get an error about exceeding matrix dimensions when I run this.
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