3
votes
1answer
95 views

Generating Palindromic_number [duplicate]

I'm trying to construct Palindromic_number, I came up with this code: ...
2
votes
0answers
135 views

Real integral evaluating as indeterminate

Mathematica evaluates the following integral as: ...
12
votes
10answers
602 views

How can I generate a nested array like this one?

Well, this is how the array looks like: I came up with this code: n = 10; Nest[ArrayPad[#, 1, 1 - #[[1, 1]]] &, {{1}}, n] /. {1 -> "*"} Any better ...
1
vote
2answers
240 views

Finding normals to a curve through a given point

I want to find x on curve $y(x)$, where curve $y(x)$ is perpendicular to point $(x_0,y_0)$. for this I minimize the distance between points $(x,y(x))$ and $(x_0,y_0)$, here's an example for point ...
3
votes
2answers
146 views

Modify all the second elements of every pair in a list of pairs

I have a list in the form {{a, 1}, {b, 2}, {c, 3}}. Let's say I want to operate a transformation on all the second elements of each sublist, but this transformation is a function of them all ...
16
votes
4answers
1k views

Plotting a contour on a torus

There are two ways to consider a two-dimensional torus. One way is to take a parallelogram (let's say the square $[0, 1]^2$) and topologically glue the opposite edges. Another way is to look at the ...
14
votes
1answer
241 views

Dynamic and LibraryLink: dynamic visualization of a simulation

I am asking this question to save some time and I am expecting answers only from people who have tried something like this before. (I realize that I could just try it and see if it works, but that ...
7
votes
3answers
514 views

How to connect Mathematica 9 to MS SQL 2012 using Windows 7 enterprise (64-bit)

I have used Microsoft Open Database Connectivity (ODBC) with Mathematica 8.0 and MSSQL 2008 on Windows XP, but I can't get it to work on Windows 7 Enterprise (64-bit) with Mathematica 9.0.1.0 and MS ...
11
votes
1answer
102 views

When is the output of examples in function documentation rasterized?

Upon building documentation in Workbench, Workbench sometimes converts the output of examples on function pages into rasterized images, and sometimes not. Does anybody know what controls this ...
9
votes
3answers
373 views

FindShortestTour for charity (or: How can I optimize meal delivery with FindShortestTour?)

I've been wondering about this for a while - but never got around to asking - until I saw faleichik's incredible answer to Mathematica Minecraft. I did some work at a not-for-profit a little while ...
3
votes
1answer
288 views

Why isn't autosave enabled by default?

While I've come across several ways to implement/enable autosave (see: Is there a notebook autosave frequency configuration?, Saving my code before cell evaluations: Insurance against front end ...
2
votes
1answer
604 views

Excel DDE Link: reading and writing in real time

I'm wondering if it is possible to link Excel and Mathematica in real time, so that Mathematica can be used as a computing and "storage" tool. Suppose I have an Excel spreadsheet with an active DDE ...
5
votes
2answers
431 views

Transcendental equation with ContourPlot3D

I am still a newbie to Mathematica, so I am still getting used to the syntax and logic of the program - but I've been trying to do the following 3D plot: ...
1
vote
0answers
97 views

Disagreement between FindGeoLocation and Alpha: “Where Am I?”

While trying to estimate a user's location in a notebook, I noticed that FindGeoLocation[] was extremely inaccurate. I realize that it uses an IP lookup to make ...
5
votes
1answer
525 views

Wallis Formula and Pippenger Product---How do we get symbolic output?

The Wallis Formula computes $\frac{\pi}{2}$ OEIS and the Pippenger Product computes $\frac{e}{2}$ OEIS. Here is a combined formula: ...
1
vote
1answer
95 views

Memory handling by ConstantArray

I noticed the following issue when using ConstantArray: a = ConstantArray[0., {10000, 100}]; ByteCount[a] (* 8000152 *) Then ...
18
votes
1answer
608 views

xkcd: Geohashing in Mathematica

On May 21, 2008, an xkcd comic proposed a method for creating a random, local meeting place that can't be determined until the day of the meeting. This method is usually used for xkcd fan events, ...
16
votes
6answers
567 views

How do I replace a missing value in a column with the value immediately above throughout a table?

I have a large table (7000 rows × 17 columns) of terse textual data. In many of the columns, empty entries have been replaced with "." as a marker. Working from the top of the columns downward, I want ...
6
votes
1answer
371 views

Building a molecule viewer: aesthetic rotations

I am working on building a molecule viewer in Mathematica and am running in to problems with controlling rotation of the molecule (which is rendered as a ...
0
votes
1answer
102 views

Counting Stochastic Processes and displaying relative value

Counting Stochastic Processes and displaying relative value I have two watermarks and multiple stochastic processes given. I want both to display and count the stochastic processes which are below ...
0
votes
1answer
219 views

Can I take derivative of a function that represents a piece of music?

Can I take the derivative of a function that represents a piece of music? The music is given in .mp3, .midi or whatever comes in handy.
0
votes
1answer
296 views

Manipulating and plotting two interdependent functions: [closed]

I want to plot two functions. Function G8 and G9. Both should be manipulable. Function G9 should dependent on Function G8. Function G8 has a bigger starting value. If function G8 increases by δ ...
1
vote
1answer
103 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
233 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
251 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
621 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
193 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
370 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
271 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
202 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
209 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
202 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
138 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
87 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
168 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
481 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
260 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
197 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 ...
25
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
298 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
414 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
496 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
216 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
229 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
820 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
143 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 ...

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