Need to make a nested loop
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I'm new at matlab, here's what i need to do. I've got a inner loop used to solve a polynomial at a given x value, But I need to evaluate the polynomial at 100 x-values. I need help making the loop work. here is what i have that does not work.
i = 1;
j = 0;
while j <= 100;
j = j+1;
%Loop used to find the solution to the polynomial at given point
while i <= n;
soln(j,i) = P(1,i)*(Xval(j)).^(n-i);
i = i + 1;
end
end
%soln
%Eval = sum(soln)
The inner loop (used to solution to the polynomial) does work. I need to run the inner loop 11 times(for a degree 10 polynomial) and the outter loop 100 times (for 100 xvalues). How can I make this work? I suck at matlab.
2 Comments
per isakson
on 4 Oct 2014
Edited: per isakson
on 4 Oct 2014
Why not for-loops? Your question is it on loops or polynomials?
Answers (3)
per isakson
on 4 Oct 2014
Is this what you try to do? With my variable names
n = 11;
P = 1 : n; % the simplest data I can think of
X = ones( 1, 100 ); % too allow me to check the result
S = nan( 100, n );
for ii = 1 : 100
for jj = 1 : n
S(ii,jj) = P(1,jj)*(X(ii)).^(n-jj);
end
end
>> S(1,:)
ans =
1 2 3 4 5 6 7 8 9 10 11
0 Comments
Image Analyst
on 4 Oct 2014
Why not just polyfit() and not bother with all that mess?
coefficients = polyfit(P, Xval, 10); % 10 is way too high for a polynomial!
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