How do I numerically integrate a multivariable function wrt only one variable?
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Hi guys,
I have a problem, since I want to numerically intergrate a multivariable function wrt only one variable. However, I only succeed by doing this with the following commands:
if true
clear
syms r s t
p0 = .75;
p1 = 3;
y0 = 720;
b = [5 -14 0.08];
end
if true
function demand = qn(x,b)
z1=b(1)+b(2)*x(1)+b(3)*x(2);
demand = z1;
end
if true
w(r,s) = int(qn([t, y0],b),t,r,s);
cs = w(p0,p1);
end
I know this is not a numerical integration. This returns me a symbolic variable (which I do not want), but this was the only way that I was able to retrieve some value. To clarify, I want to numerically integrate the function qn with respect to x(1) from p0 to p1. Could somebody help me with this please? Many thanks in advance! Cheers!
采纳的回答
p0 = .75;
p1 = 3;
b = [5 -14 0.08];
x2=...
result = integral( @(x1) qn([x1,x2],b) , p0, p1)
4 个评论
Martijn Mouw
2018-7-9
编辑：Matt J
2018-7-9
Hmmmm. Sorry, it should be
p0 = .75;
p1 = 3;
y0 = 720;
b = [5 -14 0.08];
f=@(t) qn([t,y0],b);
g=@(p) arrayfun(f, p ) ;
result = integral( g , p0, p1)
Matt J
2018-7-9
In this case, it would be much easier if you wrote qn() with scalar arguments,
function demand = qn(t,y,b)
z1=b(1)+b(2)*t+b(3)*y;
demand = z1;
end
then this would work
result = integral( @(t) qn(t,y0,b) , p0, p1)
Martijn Mouw
2018-7-9
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