# All Questions

22 views

### How to Combine 3D graphics

I'm trying to put this solid S1 = RegionPlot3D[z - 50 <= -2 x^2 - 2 y^2, {x, -5, 5}, {y, -5, 5}, {z, 0, 50}] on top of this one ...
52 views

### Empty WhenEvent action crashes kernel

Bug introduced in 9.0 and persisting through 10.4.1 WhenEvent is new in 9.0. This is an example from the docs, slightly modified (action is wrapped in ...
18 views

### Symbolic calculation on roots of polynomial

Given a polynomial like $x^3 + a_2 x^2 + a_1 x + a_0$ with roots $r_i$, I would like to symbolically compute the coefficients of a polynomial whose roots are $r_i^3 + r_i + 1$. How can I do this in ...
248 views

### Difference between = and Ctrl+ =

What is a difference between $\textbf{=}$, and Ctrl + $\textbf{=}$? For instance there are some examples, but result is same. and
36 views

23 views

### Crash after long GroebnerBasis calculation

I am running a long computation of a GröbnerBasis and after some hours the kernel crashes. The memory usage increases enormous, and it crashes, when it reaches somewhat 4 GB RES, however it is ...
38 views

### Filtering in frequency domain

I'm trying to modify a transfer function in the frequency domain by filtering it with a Butterworth filter. For example, let's say my transfer function is of the form : ...
43 views

### Automatic process to replace missing values, coming from a second matrix

I have a large starting matrix with missing values in different columns. I want to replace this missing data as follow. First I have to check the group (last column in starting matrix) and go to a ...
46 views

### Unable to plot function with exponentials or to find all roots [duplicate]

I am not able to Plot[(-1)^x + 2^x - 2 x - 1, {x, -4, 4}] directly. Some rework might be needed with complex branch cuts perhaps. There are real roots at \$ x=3, ...
36 views

### Handling Inequality with condition

I have verifying inequality using Mathematica using Simplify command For Example I want to check whether inequality a<f ...
35 views

### Setting the value of a list item

I want to set the value of an item in a list. The code that does this has to work regardless of the depth to the list. For instance set the value of r[[1,1,1,....,1,1]] to 9. Lets say the list called ...
55 views

### Using an interpolating solution of NDSolve into an algebraic expression

I would like to use the interpolating solution of NDSolve into an algebraic expression without creating a system of a differential equation and algebraic equation. The example is the following, the ...
2k views

### How to remap a fisheye image?

I want to flatten a series of fisheye images by remapping them to a rectinlinear projection. To achieve this, I need to be able to remap the pixels of the image using fisheye correction formulas for ...
23 views

### How to embed NIntegrate inside NDSolve to solve complex functions? [on hold]

I try to solve complex nonlinear PDE functions with intergrations using NDSolve in Mathematica, but failed. To simplify my problems, I wrote the following codes, but it does not work. ...