1
vote
1answer
101 views

How to study the sign of an expression including a function, with conditions on the function?

I'm trying to study the sign of an expression, having information on some of my parameters. I don't know how to code these conditions. For example, I want to know when this expression: ...
3
votes
3answers
379 views

How to exchange two arguments?

Recently, I have being using Mathematica to write my undergraduate paper. I want to use two pattern lists such as { A -> a, B -> b, c -> C, ....} and ...
0
votes
0answers
24 views

How to put the values/points in a loop into a plot? [duplicate]

I've already make the do loop..it has 200 points..how am i going to put those points into a plot?do i need to make a list@table before doing the plot?here's my loop example, ...
0
votes
0answers
63 views

Polar Plotting in Complex Plane [duplicate]

How would I plot the following functions in the polar complex plane? $$ \phi={-k\over 2\pi r}cos(\theta_0-\theta) $$ and $$ \psi={-k\over 2\pi r}sin(\theta_0-\theta) $$ Please ...
0
votes
0answers
18 views

Using functions as input for a function - won't simplify [duplicate]

I've defined a function P[k_] := 1/[Sqrt]2 (R[k] + L[k]) where R and L generate matrices. However the output of this function never full simplifies (even when I use the Simplify[%] functions). It ...
0
votes
0answers
47 views

Problem with loading my custom package [duplicate]

I've been having quite a bit of trouble loading a package I wrote. I've followed the suggestions on related questions on this site, as well as on Mathematica's own pages, and still nothing has worked. ...
1
vote
0answers
68 views

Cells overwritten as “Null” [closed]

Last week an entire section of a notebook was overwritten(?) such that all cells (headers, text, inputs, and outputs) were merely Null. It was in a section of the ...
2
votes
2answers
202 views

Create Table of replacement rules

I want to create a table of replacement rules. ...
4
votes
1answer
202 views

How to change a parameter dynamically inside NDSolve

I have no idea how to dynamically update a parameter inside NDSolve. For example consider following first-order DE: ...
12
votes
3answers
371 views

Disentangling the data

An experiment yields a functional dependence on two variables $F(x,y)$, can be imagined as a 2D map. It is known that the function can be factored as follows $F(x,y)=fx(x) gy(y) +gx(x) fy(y)$. Given ...
1
vote
0answers
101 views

Trying to study the three points theorem of the Mobius Transformation

I am trying to study the three points theorem of the Mobius transformation. This theorem says that the Mobius transformation $M$ maps three distinct points p, q, r to three distinct points p', q', r'. ...
3
votes
1answer
126 views

How to simulate the 1-D motion of a particle under constant acceleration? [duplicate]

I am trying to represent the position of an object under freefall, but am completely lost. Here is my attempt so far: ...
2
votes
2answers
116 views

How to control Manipulate speed

I want to ask about how can we control Manipulate function so that it is not incrementing the step until the expression is calculated. I have the following simple ...
1
vote
1answer
72 views

Inaccuracy of Piecewise function? [duplicate]

I have the following issue and can't find a solution so far. ...
1
vote
0answers
45 views

Replacing list elements by other list elements [duplicate]

I am a beginner of Mathematica and need some help for the following issue. I have the following two lists: ...
12
votes
3answers
353 views

Taking Top K Occurrences

Having millions of numbers in a list, I want to take top K occurrences. MMA Commonest is very slow so I write my own versions: ...
0
votes
1answer
35 views

How to use the circledot in 3 (or any) series in ListPlot? [closed]

How to use the dots in the 2 series, with diferent color?. I know use symbols "O" instead of Automatic... but... tu use de dot? ...
9
votes
2answers
2k views

Why is this semicolon in red?

I have a piece of code that works well, but when I put a semicolon after a plotting statement, the semicolon appears in red. What's the error?
0
votes
0answers
261 views

What algorithms does NSolve use?

I've been using NSolve to find roots and now I've been wondering what underlying algorithm mathematica uses. It's probabaly similiar to ...
10
votes
1answer
169 views

Importing an mx file into a context

Consider the following simple code which dumps the global context: var = 5; DumpSave["test.mx", "Global`"]; Now, in a new notebook, I would like to import var in ...
6
votes
2answers
467 views

Combining three R, G, B matrices into a single matrix of 3-tuples?

Working with Mathematica 8 on OSX here. I have three $1024 \times 1024$ matrices representing the counts from consecutive exposures onto a CCD with $R$, $G$, and $B$ filters on it, and am looking to ...
2
votes
1answer
87 views

LogPlot and LogLogPlot do not output their legends correctly

When I give lists of functions to LogPlot or LogLogPlot with the option of PlotLegends, ...
6
votes
3answers
257 views
1
vote
0answers
431 views

Derivative of the Absolute Value Function in Mathematica looks very different from the actual answer

Derivative of the Abs Function in Mathematica looks very different than the actual answer. Why? How to correct this? For example I entered ...
14
votes
1answer
268 views

Mathematica 9 cannot solve a difference equation that Mathematica 8 can

Consider RSolve[{a[n + 1] == 2 a[n] + n (1 + 2^n), a[1] == 1}, a[n], n] Mathematica 8 can solve this quickly, but Mathematica 9, even after being allowed to run ...
4
votes
2answers
170 views

TreePlot, VertexRenderingFunction and stretched vertices issue

Recently I found the following TreePlot issue. For simplicity, I took an example from Mathematica Tree Drawing Tutorial and set ...
5
votes
3answers
254 views

Split list of states by run lengths and discontinuous changes in state

I was asked to look into writing some simulation code for a user, where the simulation output (x) would oscillate between three possible states: ...
1
vote
1answer
230 views

To solve Cylinderical PDE

I want to solve this PDE. I have tried to solve it with NDSolve but found error 'Boundary values may only be specified for one independent variable. Initial ...
0
votes
1answer
337 views

Computing the volume and the curved surface area

I'm trying to compute this function $y=\frac{1}{2}e^x+\frac{1}{12}e^{-3x}$ to get the volume of the solid of revolution when the area under the curve is revolved once around the x axis. And than get ...
1
vote
1answer
117 views

Why is Mathematica not able to calculate more digits [closed]

When I want a numerical value with a precision of 50 digits... N[1.15/(1 - E^-0.2)^2, 50] Why is Mathematica not able to provide the desired solution? And I ...
6
votes
1answer
565 views

Stacked Line Graph with fragmented data

Let's start with what I already found on the internet: ...
5
votes
1answer
146 views

Adjust the opacity of the lines in a ListPlot

Here is what I am trying to plot: ...
1
vote
1answer
194 views

Simplifying fractions

What ComplexityFunction (or other technique) can I use to have Mathematica pull things out of fractions? I have a rational function of several variables and I'd ...
0
votes
1answer
66 views

Show List of HighlightGraph Objects in Matrix

I'm new to Mathematica and can't get my problem solved. I want to display a list of HighlightGraph objects in MatrixForm like ...
0
votes
1answer
242 views

How to simplify power series in terms of functions

For example, after some computations mathematica outputs $$ \sum_{k=0}^{\infty} \frac{k g_k z^{k+4}}{(1-z)^3} $$ and we assume that $$G(z)= \sum_{k=0}^{\infty} g_k z^k $$ so the question is: how ...
4
votes
0answers
267 views

Do any mainstream text editors support Wolfram Language syntax for highlighting?

Syntax Highlighting for Mathematica on a Blog There is the above, but I'm not terribly excited to install rogue packages. For example on github, I share lots of Mathematica code. I see no way to ...
0
votes
0answers
95 views

How to save the results in an identical Excel file (.xls) in each iteration of a Do loop

Assume the following code (Below code is just an example to clearly illustrate my problem): ...
3
votes
0answers
143 views

Is it possible to model the piano key attack?

My purpose is to model the attack of a piano key. As the key is pressed a sound must be emitted. When the key is released the sound must stop with decreasing volume. I have a partial success when ...
0
votes
1answer
73 views

What's going wrong with this button! [duplicate]

I'm implementing an Adaline algorithm where all inputs are 1x5526 and the output is a number from 1 to 10. I have this two functions defined and worked outside the ...
7
votes
1answer
197 views

Plotting plain data (single value lists) in 3D

Some Chemistry data sets I am trying to plot some titration data with Mathematica. I have done 4 experiments and gathered around 70 pH points (one for each milliliter) during each session, and ...
1
vote
3answers
157 views

How to make list plot when all information is in a single list

I want to make a plot , where the data is structured like so { {"l1", "l2"}, n1, n2, n3} } The values in the inner sub list are labels which are associated with ...
2
votes
0answers
100 views

Alternative for citation management in Mathematica 9 for Mac

I have just read that Mathematica 9 for Mac does not support Citation Management. Any ideas of a poor's man replacement so I can still use Mathematica on Mac for editing? I mean, have someone written ...
1
vote
1answer
318 views

Multiple plots on same graph for different parameter?

I would like to be able to Plot a function (with an implicit Integrate command) with various values for a certain parameter ...
1
vote
1answer
189 views

Import CSV with “Numeric”->True and “DateStringFormat” problem

The CSV file linked below has 3 columns: "PT_ID" (char 4), "PHYS_ID" (char 2) and "VISIT_START_TIME" (varchar eg "0:00:15" hours minutes seconds) ...
0
votes
0answers
39 views

Filter sublists that contain a certain value [duplicate]

This question is a followup from appending elements to sublist mergedList = { { {"a","b"}, -1.5, -5, "no" }, { {"c","d"}, -2,-10, 7 } } I ...
0
votes
1answer
75 views

If statements with a Boolean [duplicate]

If I have a vector {1,2,3}, I want to write an If statement, where if one of the positions is "1", it will perform a certain command. ...
7
votes
2answers
250 views

Mesh at Ticks positions

In a ListPlot3D[ ] I want to have the Mesh at the same positions as the ticks. For some reason this isn't default if both are ...
2
votes
2answers
182 views

Display truncation of numerical values when writing to a file

I am trying to copy some numerical values of parameters from a plain text file into Mathematica, then arranging them in a list and exporting them to another text file, with .ini extension. My problem ...
2
votes
3answers
266 views

appending element to sub list [duplicate]

I have a list of the form: lstA = { { {"a","b"}, -1.5}, { {"c","d"}, -2 } } I wanto to add another value to each sublist that ...

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