3
votes
3answers
129 views

How to pick the maximum of a list? Improving efficiency

I need to find the element of a list, with the highest weight. Example: ...
5
votes
2answers
196 views

Visually differentiating arguments of If

Is there a convention for writing If expressions to visually differentiate between the different arguments? For example: ...
1
vote
1answer
61 views

List Manipulation and Removing Cases

I've imported a large data set, manually removing headers in the .rtf file where it originates. However, when I import this data, I receive this output: ...
0
votes
1answer
54 views

Position of elements in a list satisfying some criteria - Understanding the syntax [closed]

From this post: if one wants to know the position of the elements of a list that satisfy some criteria, (s)he can do something like that: ...
2
votes
0answers
67 views

Integrate with Subscript: does this crash your kernel too?

I encountered some strange behaviour running v10.0.1 on a Mac Pro, while working with Integrate and Subscript. Starting from a ...
5
votes
2answers
517 views

Plotting a contour line in 2d on a 3d surface

I have a list of data which I can plot as a surface with ListPlot3D. Moreover I have a set of other surfaces and I have plotted the projection of their intersection ...
12
votes
0answers
132 views

Why does this happen with FullSimplify? [duplicate]

It is stated at the Wolfram Documentation Center (FullSimplify/Possible Issues) that: Why and when this could happen? How to avoid it? Any patterns? Edit: As pointed out in the comments, this ...
1
vote
2answers
148 views

Colorizing thresholded images with different colors

I am switching from IDL (from exelis) to Mathematica and want to do the following: thersholding a image (all values above a certain threshold are set 1, the rest is 0 ) colorizing the thresholded ...
8
votes
1answer
108 views

Decomposition of a semialgebraic set into connected components

Is there any built-in function for doing decomposition of a semialgebraic set into connected components? The only way I now can think of is to use ...
2
votes
1answer
153 views

Seeking simple function in interval

I am a bit rusty, and struggling to solve this problem. Looking for a simple, well behaved parametric function f[t], from [0,1] to [0,1] such that: f[0] = f0; f[1] = f1; f'[1] = ff1; where -1<= ...
1
vote
1answer
90 views

Using grids in manipulate

I have a few questions. Here is the code so far: ...
0
votes
1answer
129 views

Why this region is bad?

I want to draw a region but the result of Mathematica is not good. Why? ...
3
votes
1answer
175 views

How to enforce mathematica to analytically evaluate roots?

I am interested in simplifying expressions involving HeavisideTheta. A simple example could be: HeavisideTheta[1 + x - x^2 + x^3] The best I can achieve is with ...
0
votes
0answers
25 views

Filling not working when function in SetDelay [duplicate]

I want to use Plot with a SetDelay. Then Filling does not work. In the following, the first works, the second does not. I would like to get the second to work: ...
3
votes
3answers
181 views

Trouble with Position[]

I am in trouble with Position, Although my example works as expected it throws a warning. Position[{{a,b},{a,c},{a,b}}, _?(#[[2]]==b&), {1}] During ...
6
votes
2answers
159 views

Difference between Evaluation>>Quit Kernel and Quit[]

What is the difference between Evaluation >> QuitKernel and Quit[]? Both seem to quit the kernel (and clearing all ...
0
votes
0answers
45 views

How to solve ReplaceAll problem inside Manipulate

I'm running into some trouble when I try and use Manipulate (code included below). Instead of letting me manipulate the plot, I get an empty plot and this: ReplaceAll::reps: ...
0
votes
1answer
43 views

Simulating from Custom Function

I am going through an old research paper and I am stuck in one area of the coding. I'll spare you with most of the details but the function I want to simulate from is a complicated multivariate beta ...
0
votes
2answers
722 views

How to find volume of an egg [closed]

I am a first time user of mathematica. I've been trying to figure out how to find the volume of a) f(x)=(ax^3 + bx^2 + cx + d)sqrt(1-x^2). I have been scouring the internet for a solution on how to ...
1
vote
0answers
81 views
1
vote
0answers
137 views

Best way to create symmetric matrices with block structure and additional symmetries of the submatrices

Update: you can now skip the "My attempted solution" part and jump to "My first attempt for improvement" in the end of the question. My question is related to Best way to create symmetric matrices . ...
0
votes
1answer
88 views

How should i correct this error?

Sn = Sum[1/((k + 1)^2), {k, 1, n}] SSn = Sum[Sn*Fibonacci[n], {n, 0, m}] Limit[(1/(Fibonacci[m + 2] - 1))*SSn, m -> Infinity] Limit::ztest1: Unable to ...
6
votes
1answer
324 views

How to code around known MMa special-case failures?

Fourier Analysis and Signal Processing often require these integrals on functions f[x] that won't be known in advance. ...
1
vote
0answers
43 views

Question on Function in Replacement Operation

I am trying to create a replacement function which, depending on the input, gives an additional minus. In my example I have an undefined function a with two ...
5
votes
0answers
154 views

ImportString JSON possible bug

My problem is when I catch up some json output of whatever method and process it with ImportString[%, "JSON"], The first time ...
0
votes
0answers
53 views

How should I correct in the sintaxis of URLExecute

I usually perform a call to a APi with the next line: URLFetch["https://api.twitter.com/1.1/application/rate_limit_status.\ json?resources=search", "Method" -> "GET", ...
1
vote
1answer
128 views

Plotting multiple curves on a surface

I'm reading about non-euclidean geometry, and I tried to visualize hyperboloid model of hyperbolic geometry using Mathematica. What I need to do is to accent intersections between hyperboloid $x^2 + ...
10
votes
1answer
141 views

Using SendMail with new Google Security Rules

Normally, to send mail by Mathematica, I use something like this: ...
1
vote
2answers
111 views

How to find roots of a system of equation when number of equations and variables don't match?

I'm trying to check if a system of equations has a solution around a given point, the problem is that I'm using FindRoots and doesn't work when there are a different number of equations and variables, ...
0
votes
0answers
52 views

Where to put manipulate brackets for slider effect to refresh page

In order to move the plane of a best fit around to alter the sum of the residuals, I have decided to pick on one point and attach a slider to it, this adds a little variance and moves the table ...
0
votes
1answer
92 views

Character segmentation in poor quality grayscale

Given grayscale lines from a receipt like this: , in which parts of the letters sometimes appear almost as light as the background, my goal is to determine the $x$-positions of the centres of the ...
1
vote
1answer
83 views

How to rotate vectors in vector plot?

I'm writing an exam for my calculus students and am seeking help with using Mathematica on a particular problem. Here's my idea: I want to give a multiple choice problem that has four choices of ...
2
votes
1answer
80 views

How to “undo” SetOptions (restore defaults)

Say I had some good reason to use, for example SetOptions[Plot,ImageSize->500, LabelStyle->OutrageousPink]; But now sometime has passed, life has changed, ...
2
votes
0answers
110 views

Is this a bug in NCAlgebra library?

In course of my work with NCAlgebra package for Mathematica, http://math.ucsd.edu/~ncalg/ , I encountered unexpected behavior of replacements. I am using ...
1
vote
1answer
140 views

how to make a recursive function to analyse this file

I am stuck at this problem beginning We assume we have keyword k, and the structure in the file: file.txt ...
3
votes
0answers
59 views

HMAC authentication to Google Maps API

I am attempting to authenticate with the Google Maps for Work API and am having trouble computing a request signature per Google's specifications. The specifications are here: ...
1
vote
1answer
63 views

Twisting a graph layout (by fixing the $x$ coordinate of all its vertices)

I would like to draw a given graph $G$ in a specific way and I would like to know whether Mathematica can do it in a (semi-)automated way. My goal is to draw the graph $G$ in 2D, fixing all the $x$ ...
1
vote
0answers
92 views

Fitting curves with NonLinearModelFit not working with charge and discharge like data

I'm trying to get a reasonable fit out of mathematica, but i'm not very practical with it. I'm not that good with mathematica at all actually(like cleaniness of the code...). btw, here's my problem: ...
6
votes
2answers
469 views

How Can Notebook Know When it Called by Another Notebook?

I would like a notebook to behave slightly differently depending on whether it is evaluated from another notebook; i.e., ...
0
votes
0answers
97 views

Showing contours on top of a ListPlot3D

I have a ListPlot3D that currently has the default settings for mesh. Instead I would like to show a contour plot on the ...
0
votes
3answers
62 views

How do we solve an equation for a product?

I've been asked to verify my maths with mathematica - today is my first time using it. The maths is simplest if we make a substitution. I have a = bcd/fg and I ...
0
votes
0answers
95 views

Boundary value problem: complicated functionals

I am trying to solve a non-linear boundary value problem where the differential equation is a convoluted function of the variable I am trying to solve for. I have attached the code defining the ...
3
votes
1answer
352 views

Define and plot a piecewise function with parameters [closed]

I have this function , but i do not know how to define it in mathematica \begin{equation} f_t(x)=% \begin{cases} i& \text{$\frac{1}{1+i}<|x-t|\le \frac{1}{i}$} \\ ...
3
votes
0answers
59 views

Lists for built-in functions that can work without brackets

I just noticed that Exit and Quit can work without brackets i.e. a single Exit or ...
4
votes
0answers
126 views

LowpassFilter in v10: unit issues?

Bug introduced in 10.0.0 and persisting through 10.0.2 or later I tried this with a clean start and no documents loaded. Now, evaluating the following on the documentation page for ...
3
votes
1answer
90 views

NIntegrate and Interval regions

NIntegrate does not seem to like Intervals as regions. Consider the following example function defined for a parameter "a" ...
2
votes
1answer
134 views

Mathematica notebook is corrupt

Well great, I had some work done (though it wasn't much, it was just laid out nicely) in a cdf file. My computer decided to shut down on my randomly while I was working on it (some kind of error). I ...
0
votes
1answer
84 views

Extract ROI from image by hand into Matrix Form

I have a 3D Image (each pixel contains information for various wavelengths). I draw the image for one wavelength by using ...
0
votes
0answers
43 views

Troubles with FindFit for ODE (elaboration)

I have asked a question Troubles with FindFit for ODE and get a good-working answer from @belisarius. Nevertheless I need to clarify is it possible to define the same model with ...
2
votes
1answer
82 views

FindDistributionParameters and Hypothesis Testing

Please excuse me if I am making any logical error in posting this question since I am not a math major. However, let me post my question. I am trying to fit multivariate parametric distribution to ...

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