# All Questions

95 views

### Generating Palindromic_number [duplicate]

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

### Real integral evaluating as indeterminate

Mathematica evaluates the following integral as: ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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: ...
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 ...
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: ...
95 views

### Memory handling by ConstantArray

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

### Is there a method to enumerate the keys/values of SystemUtilitiesHashTable

Lacking from the simple API of SystemUtilities`HashTable is a method to enumerate the keys/values. ...
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 ...
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 ...
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 ...
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: ...
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 ...
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 ...
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: ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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, ...
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 ...
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 ...
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 ...
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. ...
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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