All Questions

1
vote
1answer
105 views

Is it possible to create a styled cell with pre-defined content?

When you create a new styled notebook from the Stylesheets chooser dialag, you get a new notebook using the chosen style with some sample content provided. But if you apply styles from the same ...
9
votes
1answer
249 views

WhenEvent and partial derivatives

Can WhenEvent be used to reset the conditions on a PDE at a given time? How would the syntax of that be? This is the code I`m using ...
4
votes
2answers
264 views

Simplifying the trace of a matrix expression

I have a long expression involving matrices that I derived using the NCAlgebra package. Can I simplify the trace of the expression? For example, say b is a scalar ...
14
votes
7answers
634 views

A function that accepts a pair or a list of pairs

Probably a duplicate, but it's not easy to search on "lists". I have a function that accepts a list of lists, say {{a1, b1}, {a2, b2}, {a3, b3}} and performs some ...
2
votes
0answers
194 views

Plotting equipotentials gone wrong [duplicate]

I'm plotting the equipotential of the potential function: $$\phi(x,y,z):=\frac{1+x^{2}+y^{2}+z^{2}}{[\left(1+x^{2}+y^{2}+z^{2}\right)^{2}-4z^{2}]^{1/2}}$$ Mathematica code: ...
0
votes
0answers
381 views

Coefficient of determination (R squared) of EstimatedDistribution

I have estimated the distribution for a set of data as LogisticDistribution[3.5, 1.037]. How can I calculate and plot the coefficient of determination (R squared) ...
8
votes
5answers
277 views

Wrapping a function in count

I am working through the Programming Paradigms via Mathematica (A First Course) and am attempting to answer the following: Use recursion to count how many times the argument can have its square ...
10
votes
1answer
203 views

Is there a method to enumerate the keys/values of System`Utilities`HashTable

Lacking from the simple API of System`Utilities`HashTable is a method to enumerate the keys/values. ...
0
votes
1answer
242 views

Plotting the simulation of Brownian Motions with multiple thresholds

I have the following problem: I have a watermark in this model where not only the mean of all stochastic processes is calculated, but also the mean of those processes which remain beyond a given ...
1
vote
1answer
219 views

NIntegrate converging too slowly when increasing size of array

I have a problem with a numerical integration. I have a 4x4x4x4 array that has for each entry an integral and I want to use NIntegrate to evaluate it. It gives me ...
6
votes
2answers
1k views

Finding y given x from an interpolating function

I would like to put a dot on the point of a curve that has a specific y value but I don't know the x value. A simple example of my code is ...
20
votes
15answers
1k views

How do I extract the middle element(s) of a given list?

How do I extract the middle element(s) of a given list? Here is some code that works, but seems a little too long: ...
0
votes
1answer
152 views

Mathematica issue with Plot, D and SetDelayed [duplicate]

I've tried to run the following code: f[x_] := 2 ArcTan[x] + ArcSin[2 x/(1 + x^2)]; Plot[D[f[x], x], {x, -4, 4}] Same with ...
1
vote
0answers
24 views

valuation to a function using a list [duplicate]

What I want to do is to evaluate a function as shown below: LessQ[n_] := LessQ[n] = l[n] < 61 In some cases, when I am sure that on a list the ...
1
vote
3answers
88 views

How can you form a variable from a function and its arguments?

Is there a way to make the general replacement foo[x,y,z]->fooxyz so that I can treat the x_i as variables so that I will obtain foofgh from the following: ...
5
votes
1answer
169 views

What is the fastest way to maintain a large set of expressions?

In my algorithm I need to maintain a set (an unordered list of distinct elements) of expressions supporting two operations: Test an expression for membership in the set Adding a new expression to ...
1
vote
3answers
518 views

plot a tube via a 4D plot [duplicate]

I have a function f[x_, y_, z_] := Exp[-x^2]*Exp[-z^2] which traces out a tube along $y$. Is there a way to plot this 4D function, where the plot color is the ...
2
votes
1answer
281 views

Numerical integration involving Inverse Normal CDF

I'd like to evaluate the following numerical integration using Mathematica $$ \ \int_0^T\int_0^\infty xe^{-0.04 s}g(x,s) dxds\ $$ where g(x,s) is a Gaussian copula function with say, marginal ...
5
votes
1answer
208 views

Accurately evaluating the hypergeometric function

As part of another problem, I am working to evaluate hypergeometric functions such as Hypergeometric2F1[1, 1, n, -1] for large $n$. I am hoping to obtain at ...
26
votes
5answers
1k views

Tips on giving a lecture course using Mathematica

I've had a look at this question on giving presentations with Mathematica which is very useful on the technical side of setting up slideshows. However, my question is more about the integration of ...
4
votes
1answer
349 views

How does Mathematica's LowpassFilter work?

I don't really understand the documentation for the LowpassFilter[] function in Mathematica. In the course I have about signal processing, low-pass filters come in ...
2
votes
0answers
528 views

mathematica for learning? [duplicate]

Mathematica looks like an extremely powerful tool. I would love to have it in my toolbox. Unfortunately, I can hardly add two numbers together. I think the application of math through programming is ...
8
votes
1answer
563 views

Integration strategies for oscillatory multidimensional function

I am seeking to integrate a highly oscillatory, multidimensional function. I am currently using NIntegrate's QuasiMonteCarlo approach. However, this is time-consuming and, given my current resources, ...
1
vote
1answer
263 views

plotting output from FindRoot

I am an R user and am totally new to Mathematica. I am trying to find the roots of a system of two equations over a series of paramter values and plot the results. I can do the computation but would ...
6
votes
1answer
255 views

String pattern search and replacement — it works, but produces error messages only the first time it is called

I defined a function in Mathematica to process a pre-generated string. More specifically, I'd like to process some parts of C codes generated from MMA. Basically what my function does is to expand the ...
6
votes
2answers
907 views

How can I compute and plot the 95% confidence bands for a fitted logistic regression model?

I have a set of binary data that I' d like to fit a logistic regression model to and show the 95% confidence band around the fitted function. I can produce the regression model but how do I compute ...
2
votes
1answer
67 views

Adjust the results of evaluating Table so it can be used as a argument to Point

I have a list generated by Table as below. ...
3
votes
0answers
146 views

Trouble with Minimize

Minimize[{t^2, 1 == 3*t + 16*u}, {t, u}, Integers] It does not give the solution t = -5 and u = 1. Am I missing something? The solution being known and ...
2
votes
1answer
162 views

Poor Graphics3D rendering

I am rendering a world environment simulation in Mathematica with Graphics3D code: ...
0
votes
1answer
108 views

Displaying Values of Fuction at end of Period by Grid

My intention is to place the values of two function into a small box within my chart. To be more precise I have two vectors. A meanvector which shows the average value of all simulated stochastic ...
3
votes
3answers
205 views

Preventing notebook cells from being broken across two pages when printing

Sometimes I create a number of plots together, e.g. by GraphicsGrid[]. If it happens that I have to print the notebook, very often the cell is broken, half on one ...
0
votes
1answer
353 views

Bar Chart Labels Mystery

I have some data which I want to plot in a simple bar chart: ...
7
votes
1answer
363 views

Numerical contour integrations in the complex plane - contour deformation gives different answer for analytic kernel

I am trying to do a contour integration in Mathematica numerically. In particular, I'm checking the identity: $$ H_m^{(1)}(z) =\frac{i^{-m}}{\pi}\int_{-\pi/2 + i \infty}^{\pi/2 - i \infty} \exp[i m ...
3
votes
0answers
156 views

Use JavaScript to evaluate webMathematica tags?

In my HTML form I have 3 buttons. Each button calls different .mx files, based upon an .mx file data. ...
1
vote
2answers
282 views

Scatterplots for subsets of multivariate data [Updated]

Update/Re-write There has been a lot of ambiguity over what i'm am trying to do with this question so I have decided to give it a full rewrite. I'm really sorry for the confusion. If you want to see ...
1
vote
1answer
108 views

space lost when converting inline cell to tex

Sample Cell 1 words with spaces in one inline cell ...
4
votes
2answers
232 views

Disk is displayed distorted in plot

What is the problem with my plot? I want to get a disk shape. ...
8
votes
4answers
393 views

Partitioning a list by recursion (Programming Paradigms via Mathematica (A First Course))

I am working through the course Programming Paradigms via Mathematica. One of the homework exercises for the section Recursion I: Passing the Buck is as follows: Use recursion to partition a ...
1
vote
0answers
66 views

Will aliasing the Quantity and UnitConvert functions to “in” and “to” create problems?

It seems that there is a lot of interest in enhancing the use of units in Mathematica; various solutions in the name of brevity, correctness, and general utility have been demonstrated. I've begun ...
0
votes
0answers
38 views

NIntegrate issue to do with unknown types [duplicate]

I have a numerical function zz: zz[s_ ? NumericQ] := so3toE3[Inverse[yn[s]].ND[yn[k], k, s]]; The other functions involved have 2 pages of code defining them so ...
15
votes
2answers
560 views

Twirl Image Transformation

I am looking to reproduce the functionality of Photoshop's "Twirl" filter, which twists an image that originally looks like this (pulled from this page): Into this: Ideally, I'd like it to ...
5
votes
4answers
482 views

Combining the second elements of a set of ordered pairs based on their first element [duplicate]

I have a large set of ordered pairs and I am trying to add the second elements together for any group of pairs that has the same first element. For example my data looks like: ...
2
votes
1answer
125 views

Odd edge-case behavior of Block

In this example, Block is used to localize the variable cache as used in the function g when called from the function ...
2
votes
3answers
282 views

How to Export the current graphic state of a dynamic module?

After manipulating the graphics in a dynamic module like this: Synchronizing manual rotations for multiple Graphics3D outputs? How do I get at the current graphic so that I can Export the image? ...
5
votes
1answer
144 views

How can I program the RiemannR function using the LogIntegral command?

I would like to program the RiemannR function using the LogIntegral command because I would like to later experiment with a ...
0
votes
2answers
202 views

Random variates in Recurrence Function

I'm completely new to Mathematica and can't seem to find an answer elsewhere so hopefully I can get some help here. I'm trying to plot a recurrence relation, where a random variate is generated at ...
1
vote
3answers
206 views

point-wise transform of `Plot`

Suppose I have the following plot: Plot[(1 - p2)^2/(p2^2 + (1 - p2)^2), {p2, 0, 1}, AxesLabel -> {"p2", "p1"}] Now I want to do a point-wise transform to ...
0
votes
1answer
126 views

Stopping- threshold and stopping- time of stochastic processes.

Rod Lm helped me to generate the following code, which I want to extend a little bit. So my intention is to use the threshold (the green line) as boundary in the following way: as soon as the process ...
4
votes
2answers
873 views

Plotting a Complex Valued Function

Suppose that a complex valued function f[z]=f[x+i y]=u[x,y]+i v[x,y]. I want to plot3d its real part by coloring it with respect to its imaginary part. For ...
1
vote
1answer
140 views

Running out of memory using FindMinimum with ParametricFunctions

I am running a pretty large optimization problem which actually consists of an outer an inner optmization problem. I use ParametricNDSolve for solving a ODE system. When the optimization is done, ...

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