Is there any notation for the calculation of this sum ??
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I want to calculate a sum of products of the form :
1.1*a^2*b^9+1.4*a^7*b^4+0.25*a^6*b^8
where a and b are constants.
This expression is the sum of 3 products, I am giving it just for simplification, but the reality is that I have to calculate a sum of 47 products of this form and in each product the coefficients (1.1, 1.4, 0.25) are different and the powers (2, 9, 7, 4, 6, 8) are also different from one product to the other.
So, my question is : Is there any notation that I can use to calculate the sum above without having to repeat each time the constants a and b ??
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Respuesta aceptada
Azzi Abdelmalek
el 8 de Oct. de 2012
Editada: Azzi Abdelmalek
el 8 de Oct. de 2012
example
x=11
a=[1 2 3 4];
p=[10 15 20 25]
sum(a.*x.^p)
% the result is
a(1)*x^p(1)+a(2)*x^p(2)+...
./ and .* and .^ are operations element by element
for your case
c=[1.1 1.4 0.25 ]
p1=[2 7 6]
p2=[9 4 8]
a=10;b=30
out=sum(c.*a.^p1.*b.^p2)
you can also create a function
f1=@(c,p1,p2,a,b) sum(c.*a.^p1.*b.^p2)
then
out=f1(c,p1,p2,a,b)
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Más respuestas (2)
kamal kiki
el 8 de Oct. de 2012
2 comentarios
Azzi Abdelmalek
el 8 de Oct. de 2012
Kamal it's not a function file. just write
f1=@(c,p1,p2,a,b) sum(c.*a.^p1.*b.^p2)
then
c=[1.1 1.4 0.25 ]
p1=[2 7 6]
p2=[9 4 8]
a=10;b=30
out=f1(c,p1,p2,a,b)
Wayne King
el 8 de Oct. de 2012
Why are you entering it like that?
mytotal = @(c,p1,p2,a,b)sum(c.*a.^p1.*b.^p2)
mytotal([1.1 1.4 0.25 ],[2 7 6],[9 4 8],10,30)
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