11
votes
10answers
685 views

Elegant way to map a function to only the last element of each sublist [duplicate]

Suppose that I have the following list, called test: test = {{{a1}, {a2, a3}}, {{b1}, {b2, b3}}, {{c1}, {c2, c3}}}; Now ...
2
votes
3answers
307 views

How to Compute Aggregate Best and Worst Cases for a Large Number of Estimates?

I need to aggregate multiple estimations, but I haven't been able to find a built-in function in Mathematica that aggregates multiple probablity estimations (I am specially interested in estimations ...
19
votes
5answers
9k views

How to find the domain and range of a function with Mathematica?

I'm studying calculus and in some exercises I am asked to find the domain and range of a function. Does Mathematica have already a built-in function for this? I can imagine some ways of doing so, ...
5
votes
2answers
5k views

Creating custom functions with multiple arguments

I am hoping that this isn't a stupid question so feel free to vote it for closure. Google failed somehow. I want to define a custom function (more complicated than the usual ...
0
votes
2answers
134 views

About minimizing calculations when using ComposeList

I have a lot of functions to use in a iterative way, and I need some of the calculation results. For example: ...
2
votes
1answer
453 views

Assumptions with D

I want to give assumptions for the D function. Say I want to calculate $\frac{d|x|}{dx}$ for $x>0$, which is 1. I write ...
3
votes
2answers
2k views

How to plot an inequality?

I need some help in plotting the following inequality using Mathematica: $$\frac{1+(x/100+0.1)\times y/100}{1.15+1.15\times(x/100)\times(y/100)}\geq 1$$ assuming $x,y\in \mathbb{Q}$, the set of ...
28
votes
2answers
1k views

Define parameterized function

I would like to be able to define the gain function of a system from its parameters. Specifically, I'd like to define a function that accepts two inputs, call them $b$ and $w$, and returns a function ...
7
votes
4answers
621 views

Prepend 0 to sublists

My question is similar to this one, but my goal is to prepend a single 0 the each sublist, not incrementally many 0's. The file I'm working is a CSV containing around 50K sublists of length 35. I've ...
5
votes
5answers
1k views

ImagePadding or other means of getting whitespace when the PlotLabel is a Column or Grid

I have been having problems with exported plots cutting off a pixel or two of the text in the title of my plots. Let's assume we have some data (AR(1) noise with a high autoregressive parameter ...
3
votes
2answers
335 views
10
votes
2answers
307 views

Two-sided slider getting stuck

I'm implementing a two-sided slider to be able to set upper and lower bound in just one slider: The problem is that it can get stuck when both locators are at the far left: And I'm unable to ...
2
votes
6answers
2k views

Selecting elements from a list one by one

I have an list: l = {{4,5},{7,8},{9,5},{3,2},{1,2},{13,12}}. I want to take the elements in the list in the sequential order. For example the first element in ...
11
votes
1answer
395 views

Selectively clear DownValues

How can I clear a subset of a symbol's DownValues ? For example, suppose I have created some DownValues for $f$ like this: ...
5
votes
3answers
274 views

Is it possible to make the Button execute two or more actions?

According to the help: Button[label,action] Is it possible to make the button execute two actions?
6
votes
1answer
2k views

FeynArts not working properly

So I have installed all FeynArts folders (from 3.5 to 3.7) with FeynCalc 8.0.1., and none of it is working properly :\ First I load the path to specific FeynArts package (3.5 for instance), then, by: ...
5
votes
1answer
548 views

import complete date string to mathematica

Based on an example from here I try to parse dates from a table including the time, but it fails. This is the modified example: ...
2
votes
1answer
825 views

Solution of numerical vector equation

Suppose I have a vector equation: Y'[t]==rhs[Y[t]] and Y[0]==ConstantArray[0,n] where "rhs[Y[t]]" is a black box function ...
9
votes
2answers
2k views

Epilog->Inset crops text with large font sizes

Why does Epilog->Inset crop the first and last letters here ("a" and "g") when FontSize is set to large values (which varies ...
7
votes
1answer
1k views

Optimizing an energy functional in mathematica using variational calculus

I have an energy functional which I want to optimize using calculus of variation. It would be nice if someone could please post a working example using mathematica. The procedure is as follows, ...
14
votes
2answers
1k views

Getting an InterpolatingFunction from a ContourPlot

I have a function, say minimizeme[Ω_][β_][ϵ_] = ϵ^2 Ω - Log[2 (Cosh[2 β] + Cosh[2 β ϵ])]/(2 β); I want to find its critical points in $\epsilon$ for a given ...
6
votes
5answers
284 views

How to nest my own “times” function to get powers

I have a "times" function. I'd like to create a power function using it. It should look like this for an 6th power: ...
7
votes
5answers
3k views

Rescale axes (e.g change from Hz to THz)

I have multiple plots of permittivity against frequency, but they're hard to read because the frequency labels go from 4x10^14 to 1x10^15 in Hz. I want to label the frequency with THz instead of Hz, ...
4
votes
2answers
1k views

How to process .vtk file

I want to extract the cluster of points inside 3D box, is there any way one can do this in Mathematica?
7
votes
2answers
1k views

Is it possible to export a graph as graphic to Excel?

It is straightforward to export lists to Excel with Export. Can I export a graphic image, too? This does not work: ...
3
votes
1answer
505 views

How do I run scripts on networked computers directly from Mathematica?

The answer to an earlier question, Computers running Wolfram Lightweight Grid Manager won't fall asleep, left me with a new problem. To review, I have a computing environment comprised of: 27" ...
3
votes
1answer
754 views

Randomly selecting elements without repetition

I assigned energy values to each element in the array as per the program of Verbeia. The program looks like this ...
6
votes
0answers
121 views

What are some general strategies to avoid using For loops? [duplicate]

Possible Duplicate: Iterating over lists in Mathematica While there are some cases where a For loop might be reasonable, it's a general mantra – one I ...
2
votes
5answers
1k views

Assigning a particular value to array elements

I have an array of 10000 elements. I want to randomly assign energy to these 10000 elements using Gaussian or Exponential distribution, such that each time a particular element is selected its energy ...
6
votes
2answers
1k views

How can I open an Excel file and modify it in Mathematica?

I wanted to ask how can I view an Excel file from a Mathematica notebook and modify it. I have seen a similar question, Open Excel file with Mathematica, but the answer involves .NET. Is there any ...
6
votes
1answer
450 views

VectorPlot: How can I evaluate the vector field by clicking on the plot?

This seems like a basic feature that is somehow missing. Ideally we'd get something like a tooltip which shows the x,y position where I click (or of where the mouse is currently hovering) and the ...
4
votes
2answers
2k views

Matrix multiplication in Block Form symbolic calculation by Mathematica

I have a problem which requires taking product of two $10\times10$ matrices. I would like to do it by considering both matrices as $5\times5$ matrices such that each entry of both matrices is actually ...
5
votes
4answers
1k views

Creating lists from a string, separating words from numbers

Say I have a string that contains numbers and words, such as this one: string = "there are 1234 words and numbers 5678 in here $999"; How would I separate the ...
5
votes
2answers
256 views

Computers running Wolfram lightweight grid manager won't fall asleep

I have a computing environment comprised of: 27" iMac with dual cores running Mac OS X 10.6.8 and 2 XServes each with 2 quad cores running Max OS X Server 10.6.8 All networking by ethernet to a Time ...
4
votes
1answer
278 views

Counting the size of the minimum cut produced by MinCut of GraphUtilities`

I want to use the MinCut function of the GraphUtilities` package to find minimum cuts for a few graphs. I'm completely new to ...
6
votes
2answers
580 views

How can I make a list animation of images that fade in and out?

I'm not sure how to get a "fade in" effect.
6
votes
1answer
297 views
20
votes
5answers
4k views

Best way to create symmetric matrices

From time to time I need to generate symmetric matrices with relatively expensive cost of element evaluation. Most frequently these are Gram matrices where elements are $L_2$ dot products. Here are ...
6
votes
1answer
708 views

How to symbolically differentiate an infinite series without evaluating the series itself

I'm dealing with finite sums of infinite series. Each of the infinite series possesses a different starting index, i.e. each of the series begins at n = 0, n = 1, or n = 2. As a result, it's important ...
16
votes
4answers
879 views

Returning an unevaluated expression with values substituted in

Let's say I have a function formula[x_List] := (x[[1]] - x[[2]]) + (x[[3]] - x[[4]]); and I want to pass it a variable and get back the unevaluated formula with ...
6
votes
4answers
1k views

Can't compute definite integral

Consider a scalar field (in polar co-ordinates), $f(r) = l-r$. Now I want to evaluate the field integral over a circular region of radius $b$, centered at a distance of $x$ from the origin. According ...
3
votes
1answer
253 views

Pattern matching a multivariate derivative

I can extract the parameters of a single variable derivative with the rule D[f[x], x] /. Derivative[order_][fcn_][variable_] -> {order, fcn, variable} ...
11
votes
3answers
2k views

How do you round numbers so that it affects computation?

I'm trying to make a demonstration of how rounding to different numbers of digits affects things but I can't find a way to round numbers to a specified number of digits. The ...
10
votes
3answers
322 views

Problems Computing (in a reasonable amount of time) Solutions to a System of Inequalities

For my Cryptography research I am interested in finding solutions to the following inequalities in terms of $r$ and $s$, where $p$ is some fixed constant. $$\begin{align} 2^{p - s + 4} + 2^{p - r} + ...
14
votes
4answers
3k views

Reflect a Plot Object

I have a relatively simple operation I'd like to perform on a plot: I would like to reflect the plot across the x-axis. I do not have any tick labels, so making sure that the labels are not themselves ...
-2
votes
2answers
2k views

Plotting a parametric plot of two functions

I have two functions f1(x) and f2(x). I want to plot them such that f1 is on the axis of ...
6
votes
2answers
206 views

How to access off-cell mouse position inside an EventHandler?

Consider the following example. First, I print the dynamically updated value of the actual position of the mouse, then I print pt, which is the same but is only ...
6
votes
2answers
1k views

Inserting a jpeg image at a specified point in the XY-plane

I know how to import an image into Mathematica using the Import command. The original image can come from anywhere, but call this image "myimage" after importing ...
8
votes
1answer
1k views

Why does Export drop namespace prefixes in the exported XML file?

I am trying to generate an Excel-compatible XML file from Mathematica. First, I created a test XML file by saving a Microsoft Excel workbook as "XML Table". Then I ...
5
votes
0answers
508 views

Having problems compiling Mathematica Cuda code

Ok I am trying to follow the examples of Cuda Code in the docummentation Run the CUDAQ[] and get back a True and run some of ...

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