User login
Login with your MaplePrimes or Maplesoft.com account
Poll
Collaborative Books
Syndicate
ArrayInterpolation can be calculated, but not integrated
Categories:
I have to create a n-dimensional interpolation to get function to use it in a numerically solved differential equation.
T:=(x,y)->ArrayInterpolation(Ranges,Img,[[x],[y]],method=linear)[1][1]:
T(3.3,4.1);
1.30999999999999983
int(T(3.3,x),x=0.0..1);
Error, (in CurveFitting:-ArrayInterpolation) invalid input: coordinates of xvalues must be of type numeric
I don't need to get the actual equation of surface. I just want to use the function without restrictions. If it can be evaluated in a point or plotted, so it should be a way to use it in a differential equation.
Give me some idea how to.
Announcements
Active Main Forum Topics
Active Student Forum Topics
Recent comments
- interesting idea
1 hour 10 min ago - interesting
1 hour 13 min ago - The answers
4 hours 21 min ago - okay Alec, ofc that's the
4 hours 41 min ago - if
5 hours 1 min ago - Congratulations
5 hours 18 min ago - And what is the answer?
5 hours 43 min ago - anyway
5 hours 50 min ago - okay i got it. I made the
6 hours 5 min ago - I'm sorry, a
6 hours 10 min ago
Recent blog posts
- Job offer / Stellenangebot: Technischer Support Maple
- Table from procedure
- Maple Mentor Awards: The Big Kahuna
- The actual architecture
- new package adoption
- Conjectures ripe for Maple experimentation
- overloaded operators
- poll: change in Maple that you want most?
- The future of FourierTrigSeries package
- Maple 12.01 is now Available
Recent book pages
evalf/int and curry
I would probably try:
`evalf/int`(curry(T,3.3),0..1);
I also used instead of curry
I also used instead of curry Q:=x->T(x,3.3):
but in any case it does not work.
It can not access T as a normal function, only calculation in a point is avalible.
more info
Please tell us what `Ranges` and `Img` are.
I am imagining that an efficient in-place solution using the container=V option may be possible. But it'd help to see the structure of Ranges and Img.
acer
> restart; >
> restart;
> with(CurveFitting):
> with(LinearAlgebra):with(plots):
> Ranges := [[seq(1..5)],[seq(1..5)]]:
> Img := [[1,3,2,0,0],[1,2,1,3,3],[3,4,2,1,2],[0,1,2,2,0],[2,3,6,1,0]]:
> T:=(x,y)->ArrayInterpolation(Ranges,Img,[[x],[y]],method=spline)[1][1]:
> plot3d(T,1..5,1..5,shading=z,grid=[25,25]);
> Q:=x->T(x,2.4):
> plot(Q,1..5);
> T(2.3,4);
2.59687499999517968
> Q(3);
3.40228571428511728
So it can plot T and Q or eval them in points, but I can not use Q in a numerically solved differential equation or numerically integrate it.
evalf/Int
I believe your example will work if you use evalf(Int(Q, 0..1)). You can look at the evalf/Int (Numerical Integration) help page for more examples.
Paulina Chin
Maplesoft
evalf(Int(Q, 0..1)) really
evalf(Int(Q, 0..1)) really works! Thanks.
Now I need to solve differential equation: diff(diff(x(t),t),t)=T(x(t),diff(x(t),t)).
dsolve/numeric
For the differential equation, you'll want to use the numeric routines again. Try looking at the dsolve/numeric help page. There are examples showing how you can use operator form. "Operator form" refers to input that's in the form of a procedure rather than an expression, and this is the form used in the evalf(Int(Q, 0..,1)) call.
Paulina
Yo! It works. Thank you.
Yo! It works. Thank you.