# All Questions

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0answers
28 views

### ReplaceAll Not Working Correctly

I'm trying to use replaceall to redefine my expression in terms of a separate variable.. ...
0answers
57 views

### How to plot function with pattern-matched argument and catch-all definition that throws

Consider the following function: f[n_?NumericQ] := n; f[args___] := Throw[{args}]; Then try to plot it: ...
1answer
31 views

### Generating number sequence

I am very new to mathematica. I am trying to generate list of number sequence. I want to make 6 sequences. 1 - 10, 10 - 100, 100 - 1 000, 1 000 - 10 000, 10 000 - 100 000. All reversed. Is there any ...
3answers
144 views

### Mathematica Fails to Solve a System of 3 Equations!

I'm trying to solve what I thought would be a simple set of 3 equations for Mathematica! But it grinds endlessly without any result.. ...
3answers
905 views

### Plot the Pascalian triangle

g[n_, k_] := n!/(k! (n - k)!) /; Element[n ,Integers] && k <= n How do I plot a Pascalian triangle with the above function?
1answer
45 views

### How do I solve a large system of differential equations with indexed functions?

I strongly suspect that matrix methods are the right answer here, but I am having trouble visualizing how to set it up. Imagine a large number of coupled functions: ...
1answer
44 views

### Unable to plot Integral

I am following an example taken directly from the Mathematica book V5.2 by Stephen Wolfram, here is a screenshot from the book. And here is my implementation, the integral fails to plot. This looks ...
1answer
33 views

### Find Unknown coefficient using Contour plot

I have I really complicated equation, but for simplicity lets assume my function is F(x,y,z)= ax+by+c*z, where a, b and c are some unknown constants. From experiments we know that at: x=3, y=2, z=1 ...
0answers
24 views

### Open all notebooks in Working mode?

Is there a way to specify this as a global setting that oversides an individual notebook screen environment setting? Motivation: I have a folder of many slideshows and need to change this manually ...
1answer
48 views

### Calling a function with a vector doesn't work for me

I'm trying to create a simple function that generates a transformation matrix from the partial derivatives of two coordinate systems. It currently works when I have it written like this: ...
2answers
48 views

### How do you calculate the expected value of the sum of random variables?

For instance, when trying to compute $\mathbb{E}[\sum_{i=1}^{10}X_i]$ where $X_i \sim N(0,1)$, I input into Mathematica: ...
1answer
33 views

### How can I find EdgeWeights strongly connected components using Manipulate

Given the following Code: ...
0answers
21 views

### NIntegrate in FindRoot: s=S is not a valid limit of integration

I get an error code saying that "s=S is not a valid limit of integration" when I use the following code: ...
2answers
104 views

### How can I prevent renaming the arguments to Function[{…},…] for making plots of spherical harmonics coloured by phase

I'm trying to plot a spherical harmonic coloured by phase. e.g. ...
0answers
35 views

### Graphing f '(x) from the graph of f(x) [on hold]

Let f(x) = (x^2-4)/(x^2+1). a) Use the appropriate Manipulate[ ] command from the example in this lab to graph f '(x) from the graph of f(x) using - 3 < x < 3 and a range of -5 < y &...
0answers
19 views

### How to manipulate SphericalPlot3D as Graphics object?

I'm kind of new to Mathematica so this may sound obvious for some people. I'd really thank for your help. I'm trying to plot a lattice. At each point there is an atom. The lattice is created as ...
0answers
24 views

### How can I specify the local number of kernels I want? [on hold]

I use ParallelTable in my codes, and it can open up to four local kernels to run automatically. But how can I assign a specific number of kernels? The relevant ...
1answer
22 views

### Substitution in delayed evaluation function [duplicate]

I am trying to do the the following: precomputing an expression and then making a function out of it. It has to be delayed evalution, because some of the parameters are only known when the function is ...
0answers
35 views

### Why am I getting Ceiling[j] after differentiating when j is an integer?

I'm teaching myself Mathematica and am trying to compute the following derivative $\frac{d}{dx_j}\sum_{i=1}^{n}x_i^i$ which should give $j\times x_j^{j-1}$. However, typing the equivalent in ...
2answers
43 views

### Showing list of parametric plots

I can make two plots and show them , but I dont know how to make n plots and show them, example : ...
1answer
90 views

### Waterfall plot of a two dimensional function

I have the following plot, and I need to draw a waterfall plot of this. Does anyone know how I can make a waterfall plot in Mathematica? ...
2answers
101 views

### What is the point of tagset /:? [duplicate]

I'm teaching myself Mathematica and came across tagset. So I followed the example in the link, but seem to be missing the point. All of the below give me the same answer after assignment: that ...
1answer
37 views

### Integrating absolute value of a function

I have a symmetric spherical function, which I want to integrate to determine the volume enclosed. Since it is symmetric, simple integration after multiplying with Sin[theta] gives zero. I also tried ...
0answers
22 views

### Mathematica Lattice Reduce algorithm [on hold]

At the moment, I'm studying lattices at Wolfram Mathematica. I noticed that up to version 10, the LLL algorithm was used. But after version 10 it changed. What algorithm is used now?
1answer
31 views

### Replace expressions

Let's consider the following example ...
2answers
58 views

### Select subsets from a list based on a criterion?

Assume we have a set of numbers, for instance $A=\{2,3,4,5,6,7,8,9,10\}$ and we are looking for the sums of reciprocals such that they are less than one. I mean I am looking for all $S_B$'s  S_B=\...
1answer
39 views

### How to find the distances between two adjacent maxima in a solution from NDSolve

I try to find a general approach to plot the time evolution of horizontal distances from maximum to maximum in a solution of PDE. The solution u[x,t] normally have ...
1answer
43 views

### Problem when solving Kalman filter in Mathematica: How to define a spectral density matrix and calculate the covariance matrix?

I am reading the classic book on state-space control theory by Bernard Friedland. In order to strengthen my understanding of Kalman filter, I want to reproduce Example 11A (Inverted pendulum on page ...
1answer
26 views

### How to draw three different surfaces in a single plot where each surfaces are defined in different region?

Suppose I want to plot 3 surfaces, z=xy+y^2, x=4 & x+2y=4 together so that x=4 plane will be in the upper region of z=xy+y^2 surface and x+2y=4 plane will be in the lower region of z=xy+y^2 ...
1answer
48 views

### Why is the plot not showing up?

Does anyone know why my plot is not showing up? I get a recursion error. ...
1answer
52 views

### How to make a histogram showing the frequency of word length?

I have to analyze the novel Don Quixote, so I am trying to make a histogram where each bin is how many characters in a word, and the height being the frequency of words with that many characters.
0answers
34 views

### NDSolveProcessEquations inside Manipulate

NDSolve and NDSolveProcessEquations can handle equations with vectors on each side like this one: ...
0answers
31 views

### Why can Mathematica detect a linear term in a series expansion only in special cases?

The series expansion Series[Sqrt[2 - 2 Cos[d k]], {k, 0, 5}] Is in odd powers of Abs[k], or more precisely ...
0answers
105 views

### Need help with ParametricNDSolveValue for ODE with two variables and Do-loop

I' m trying to solve a tricky 2-nd order ODE with ParametricNDSolveValue for boundary conditions (BCs) y = 0 at R and ...
2answers
162 views

### Plotting single vectors in parametric plots

I am trying to plot something like the Frenet-Serret Formulas using a parametric plot, like this: ...
0answers
33 views

### Rewriting all terms in terms of Riemann tensor

Is there any command to rewrite all the curvature terms like $R$ or $R_{\alpha\beta}$ or $R_{\alpha\beta}^{~~~~~\gamma\delta}$ in terms of the Riemann tensor $R_{\alpha\beta\gamma\delta}$ and the ...
0answers
32 views

### Reference Calculation [on hold]

I have database of many references of numbers format L-a-b. for example: L: 76 a: 5 b: 12 (this number is not in database). to get this number I have to do this calculation L: 71.09 ...
4answers
492 views

### Reverse color of overlapping points?

Is there a simple way to change the color of the region where two Points overlap? For example in ...
1answer
59 views

### Linear map of unit cube (generalized)

This question is a slight generalization of this question. Let M be a fixed rational m $\times$ ...
1answer
43 views

### Power towers Power towers from x to n [on hold]

How can I make Mathematica calculate a power tower for a succession of numbers, but instead of writing them, Mathematica does the iterative calculation. ...
1answer
66 views

### Logistic fit of data

I would like to use LogitModelFit to find the logistic function to my data. The error I obtain is LogitModelFit::binrsp: The response values are expected to be ...
3answers
79 views

### How can I color the elements of the largest strongly connected component in ListPlot

The following Code: ...
1answer
50 views

### Linear map of unit cube

Let c be a vector of n constants and X = Table[Symbol["x" <> ToString[i]], {i, n}] be ...
2answers
48 views

### how to solve the equation

I want to sole the given equation for x. Can anyone help me please to analyse the solution. Thanks ...
2answers
88 views

### How to correctly show the slope of a linear part on LogPlot

I need to plot an Interpolation function of one independent variable (only a 3kB file) on LogPlot and show the slope of its linear part together on the ...
0answers
80 views

### Is Mathematica acurate? [on hold]

Well as I am new in Mathematica and self learner, I have this question: Is Mathematica accurate enough, when drawing a plot? My concern is that a machine can only find and therefor plot a finite ...
0answers
35 views

### How to use all nodes and cores in parallelization

Here is the link for the code that I have written, I have taken very less sample for the check. I have 10 nodes available with 24 cores, but while running this program only 24 kernels are being used ...
0answers
35 views

### How to restrict the use of variables to the notebook? [duplicate]

I am solving two problems simultaneously in which the variable x is defined. To the left of the image, i'm solving shape functions and matrix operations. But to the right i'm solving Green's function. ...
1answer
45 views

### Simply define an arbitrary, real function [on hold]

I know of a way to define an arbitrary function (say, a[x]) and then apply an assumption to it (say a[x] is real). My code is pasted below. ...
1answer
543 views

### Can Mathematica achieve this diagram?

Can Mathematica be used to create diagrams of drift diffusion of the kind shown, including histograms showing the response-time distributions? The distributions capture the time taken by a random ...

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