# Questions tagged [version-7]

Version-specific issues for Mathematica 7 (other than bugs).

88 questions
Filter by
Sorted by
Tagged with
64 views

### How to define smooth random initial conditions consistent with boundary conditions for this 1+2D PDE?

I wrote a fully working code to numerically solve a non-linear variation of the classic 1+2D waves equation. Here's a stripped down version of it (classic waves equation), with static initial ...
• 3,533
1 vote
82 views

### How to simplify this sum of random waves?

Is there a way to simplify the random functions and their calls, in the code below? ...
• 3,533
141 views

### How to make this moving surface a continuous and derivable function?

I'm having troubles in defining a function of three variables: $t$, $x$, $y$, from a moving bumpy surface that should be derivable relative to its three variables. Here's the animated surface code, ...
• 3,533
1 vote
105 views

### Randomly oscillating surface is not working well

I'm trying to built some random moving surface from a plane perturbed with random oscillators, and my current code isn't doing what I need yet, as seen from the ...
• 3,533
68 views

### How to insert variable height in this random bumps function?

I'm trying to insert a "time" variable that control the height of the random smooth bumps, but I'm yet unable to do it right, as shown with the code below: ...
• 3,533
110 views

### How to define a smooth function of random bumps in a plane?

I would like to define a simple function that gives random smooth bumps in a plane, a bit like the clumsy picture below, but it should be continuous: ...
• 3,533
1 vote
219 views

### Boundary conditions at infinity for 1+2D wave equation in Mathematica 7

To solve a waves equation, I need to define some boundary conditions. The wave is propagating on an infinite plane, and it's not a membrane fixed on some fixed support. I'm have difficulties in ...
• 3,533
285 views

### How can I add a few specific mesh (altitude-like level) curves to a plot?

I'm plotting the numerical solution of a differential equations, using the altitude-like level curves as a mesh. It's fine, but I would like to add three specific altitude levels as thick red, green ...
• 3,533
1 vote
69 views

### How to numerically solve this partial differential equation and plot the output? [duplicate]

Using Mathematica, I would like to numerically solve the following partial derivatives equation : \tag{1} \frac{\partial^2 \Phi}{\partial T^2} - \frac{\partial^2 \Phi}{\partial X^2}- \frac{\...
• 3,533
210 views

### How to draw borders around tiles of the same color?

I'm having difficulties with a project to show random tiles with a few random colors. Here's the code that I need to modify: ...
• 3,533
419 views

### How to draw random colorfull domains in a plane?

I'm trying to produce some graphics like the one shown below, with a few adjustable parameters to change the number and size of cells. The cells positions, sizes and colors should all be random (size ...
• 3,533
1 vote
94 views

### How to add noise to these random straight lines in 3D?

Here's a code that draws a pack of random straight lines in 3D: ...
• 3,533
253 views

### How to generate randomly curved and twisted strings in 3D?

Here's a code that draws a set of random straight lines in 3D: ...
• 3,533
1 vote
177 views

• 281
90 views

### Error with comments inside and expression

I found this strange parsing error with comments inside of an expression in Version 7. And example is {{1, x}, {1, y} (* {1, z (= 5+6)} *)}; It occurs depending ...
• 1,455
446 views

### Warning and Errors during Compile

I defined a compiled function cf = Compile[{{x, _Integer}, {n, _Integer}}, z = (n^x); Binomial[n, #]* StirlingS2[x, #] *(#!)/z & /@ Range[x]]; and I ...
• 51
105 views

### Reduction of repetitive calculations in Table

If I generate two tables inside a function which are function[n_, x_, y_]:=( table1 = Table[i* x/n^x, {i,1,n}]; table2 = Table[i* y/n^y, {i,1,n}]; ) where <...
• 51
123 views

### RDPStruct.exe: what is it and why are there so many?

I have an old (v7) webMathematica system running and it seems to generate a lot of RDPStruct.exe processes. First, what does this "Converter" do? GIF.exe and JPEG.exe are obvious, but "RDPStruct" ...
• 239