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Initial values - how to input vector rather than constant?
Posted 2014年2月7日 GMT-5 19:47 Parameters, Variables, & Functions Version 4.3a, Version 4.3b, Version 4.4 3 Replies
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I have set up the PDEs and boundary conditions. Now I have to set up initial conditions.
Say I have 5 mesh points. Then for a particular parameter I want the inital conditions [0,2,4,6,8] or something, so the left-most mesh point is zero and the right-most mesh point initial condition is 8.
However when I click on Model 1 > General Form PDE > Initial values node, I see a place to enter the initial conditions, however this appears to only accept a constant. So if I enter "3" then I get [3,3,3,3,3]. I have tried the following:
range(0,8/(5-1),8) --- it accepts this input but gives an error at runtime about not recognizing "range"
or I simply tried
[0,2,4,6,8] --- however it does not accept this input.
How to give a non-constant input initial condition?
Thanks!
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Did you try to define initial condition parameter as a function of space. Essentially, in the initial values field, you type:
init(x) in 1D or init(x,y) in 2D or init(x,y,z) in 3D.
But you have to define "init" under interpolation function.
Suresh
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that does not work for me? I am in axisym 2D case? is it then different?
the init(r,z) or init(x,y) in the function definitions is well plotted,
but under the initial value it does not appear?
thanks
lukas
my mistake was in the units.. init(1000*r,1000*z) was right