Is there any notation for the calculation of this sum ??
2 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
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 ??
0 commentaires
Réponse acceptée
Azzi Abdelmalek
le 8 Oct 2012
Modifié(e) : Azzi Abdelmalek
le 8 Oct 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)
0 commentaires
Plus de réponses (2)
kamal kiki
le 8 Oct 2012
2 commentaires
Azzi Abdelmalek
le 8 Oct 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
le 8 Oct 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)
0 commentaires
Voir également
Produits
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!