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# Bill Greene

### MathWorks

2012 以来アクティブ

CAE Consultant

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Deflection of a Square Plate Calculated With PDE Toolbox
Deflection of a Square Plate Calculated With PDE Toolbox

5年以上 前 | ダウンロード 5 件 | Solving 2 PDEs across one domain.
This documentation page shows how to specify an f-coefficient on a specific domain: <http://www.mathworks.com/help/pde/ug/sca...

8年弱 前 | 0

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Times 2 - START HERE
Try out this test problem first. Given the variable x as your input, multiply it by two and put the result in y. Examples:...

8年弱 前

Make the vector [1 2 3 4 5 6 7 8 9 10]
In MATLAB, you create a vector by enclosing the elements in square brackets like so: x = [1 2 3 4] Commas are optional, s...

8年弱 前

Simulation of coupled partial differential equation using MATLAB.
I took a look at your attachment and think I understand most, but not all, of the problem you are trying to solve (I don't under...

8年弱 前 | 0

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Problems with LDL factorization
Have you tried solving the over-determined system directly: x = A\b; Computing using the normal equations, A'*A, is almost...

8年弱 前 | 0

Can I use Poisson equation or any equation with desired parameters in PDE Toolbox using Rectangular shape?
Take a look at this example: <http://www.mathworks.com/help/pde/ug/electrostatics.html> Bill

8年弱 前 | 0

Why aren't the essential boundary conditions fulfilled?
I ran this example in R2014a of MATLAB and I do get -1 at the lower left corner (and upper right) I created the example in pd...

8年弱 前 | 0

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Solve parabolic coupled PDE's using MATLAB's pdepe solver?
Yes, pdepe can definitely solve systems of pde. In general, the u argument to the functions you define has as many rows as ther...

8年弱 前 | 0

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structured quadrilateral mesh in PDE Toolbox
There is no support for quadrilateral elements in PDE Toolbox-- either in the meshers or the computational modules. However, if...

8年弱 前 | 0

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How to define a temperature dependent parameters in a PDE Toolbox?
Yes, PDE Toolbox allows the coefficients to be functions of the dependent variables (e.g. temperature). This documentation page ...

8年弱 前 | 2

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Setting up the initial conditions for BVP4C?
From your call to bvpinit where you have this [0.01; 0.9] for the initial guess, it looks like you have 2 differential equation...

8年弱 前 | 1

Matlab hyperbolic PDE equation errors
There are several ways to define PDE Toolbox coefficients that vary spatially. But, defining the value of the coefficient at eve...

How to solve system of three nonlinear PDE?
pdenonlin is for solving only PDE that are not a function of time. However, the parabolic function can solve equations that a...

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Solve a non linear differential equation systems with only boundary conditions
You have a system of two first order differential equations so you need just two boundary conditions. I would guess that specify...

Reg. PDEPE 's internal discretization of time
pdepe uses the variable time step ODE solver, ode15s, internally. http://www.mathworks.com/help/matlab/ref/ode15s.html The...

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Insert f coefficient in pdetool
Do you calculate F in fcoeff? If so, you can make it a global variable and it will retain its value between calls to fcoeff. ...

pdepe daeic12 (line 77) eror
I don't see any boundary conditions on c3. I think this may be the cause of your problem. Bill

Error solving simultaneous PDEs.
The first thing I should say is that pdepe is designed to solve systems of parabolic and elliptic PDEs. Practically this means t...

create sparse matrix from diagonal arrays
This doesn't exactly answer your question but still may be useful. This example: http://math.mit.edu/cse/codes/mit18086_poiss...

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How to implement irregular, time-dependent boundary condition in PDEPE function?
I think that pr = interp1(timedata, tempdata, t) - ur; may be what you need. Assuming the lengths of timedata and temp...

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How can I solve a PDE with given coefficients in time?
Take a look at this example: <http://www.mathworks.com/help/pde/ug/nonlinear-heat-transfer-in-a-thin-plate.html Nonlinear Hea...

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Function of boundary conditions PDEPE
To set the temperature at each end to fittedmodel(t), you would define: pl = ul-fittedmodel(t); pr = ur-fittedmodel(t); ...

calculate the capacitance with PDE toolbox
One of the simplest ways to calculate capacitance using PDE Toolbox is from the energy: C = 2*U/V^2 where U is the electrostatic...

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How to control times at which PDE Toolbox solves a parabolic equation?
I'm afraid I wasn't able to run your example. I believe that your fcoeff function has an error in it. I did take a look at th...

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Calculation of Jacobian for ode15s in hyperbolic/parabolic-Solver?
If the Jacobian is a function of the dependent variables (or time), ode15s will typically call pdehypdf many times during a com...

Calculation of Jacobian for ode15s in hyperbolic/parabolic-Solver?
Hi Lena, Yes, you are correct that the Jacobian calculated in parabolic/hyperbolic is only approximate. However, in my experi...

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How to control times at which PDE Toolbox solves a parabolic equation?
>This does not yield correct results at the time values I ask it to plot the results So, why don't you request results at the...

8年以上 前 | 0

eigs - Error with ARPACK routine znaupd: info = -8
I'm not certain what the problem is but I can suggest something to try. I'll assume you really want around 20 eigenvalues. By...

8年以上 前 | 0

Does hyperbolic-solver really use a nonlinear solver?!
Hi, Unfortunately, I believe you have uncovered a bug in the hyperbolic function that occurs when you have a nonlinear equati...

8年以上 前 | 0

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