Questions on the use of numerical functions NIntegrate and NDSolve.
0
votes
0answers
68 views
Which integration strategy to use for this product of polynomials?
What would be the ideal integration strategy for a function like this: $$f(x_1,x_2,\dots,x_N)=\prod_{i=1}^Nx_i^{c_i}\Theta(x_i-p_i)$$ where $x_i,p_i\in \mathbb{R}$, $\Theta$ is the Heaviside function ...
0
votes
0answers
68 views
FindFit and NIntegrate with dependency between integration variables
I am trying to use FindFit and NIntegrate in this situation:
...
0
votes
0answers
121 views
How to integrate a multivariate normal in Mathematica? [closed]
I am trying to use Mathematica to integrate this w.r.t $x$, $x$ is 2-dimension.
It looks like this,
$\sum\limits_{i=1}^{20}{\exp \left\{ -\frac{1}{2\sigma _{i}^{2}}{{\left( x-\mu_i ...
0
votes
0answers
109 views
dealing with discontinuity at integration
My problem is about the solution of $2$ non-linear equations which have a single parameter. To be more precise, For given two densities; for example:
...
0
votes
0answers
85 views
Issue with WorkingPrecision
I am having the following issue.
I am evaluating a numerical integral, and I need high precision to get good values of the function being integrated.
...
0
votes
0answers
72 views
NIntegrate, view integration options [duplicate]
The Mathematica manual says:
NIntegrate symbolically analyzes its input to transform oscillatory and other integrands, subdivide piecewise functions, and select ...
0
votes
1answer
110 views
Nested NIntegrate - NIntegrate::inum: - error
I have the problem quite similar as in:
Nested NIntegrate
I define two functions:
...
0
votes
0answers
41 views
Contour integration [duplicate]
Possible Duplicate:
Symbolic integration in the complex plane
Does mathematica do Contour integration ? like this one :
$\displaystyle \oint_{\gamma} f(z)\ \mathrm{d}z $
if yes, how ...
0
votes
0answers
125 views
Numerical solution of a system of ODEs
I have to solve set of coupled first order ODE's
$y_1=z$, $ y_2=\frac{dz}{dt} $;
$\frac{d^2y_1}{dt^2}=\frac{dy_2}{dt}=\frac{(p_s-p_f)}{p_s}g-\frac{9u}{2a^2p_s}y_2 $
Using the Euler method and the ...
0
votes
0answers
187 views
Mathematica 9's NDSolve treats sum as an integral [closed]
Sum and integral are threated the same by NDSolve in Mathematica 9:
The problem was also in Mathematica 7. I submitted a bugreport to the technical support, they admitted this is a bug, fixed it in ...
-1
votes
1answer
297 views
Need help with solving non-linear differential equation [closed]
I am new to using Mathematica and have a problem at hand: I need to solve
$y''(x)+ a \sin(y(x)) = 0$ and plot the output, I need a "manipulate" thingy for the two initial conditions. Help needed.
-1
votes
1answer
119 views
double integration
I want to evaluate a double integral, but the limits of one integral is a function of the second. Like this
...
-1
votes
1answer
55 views
FindFit and Integration errors
First off, appologies for what may sound like a newbie question, as I am very new to using Mathematica.
I am trying to find a way to get Mathematica to give me an expression that would describe the ...
-4
votes
0answers
59 views
Very long evaluation time of NDSolve [closed]
The following code takes a very long time, and I am not quite sure why. The Quiet is needed as otherwise there are many error messages of the form ...
