# All Questions

158 views

### How to count number of {True,True} outputs?

Do[Print[{x + y + z == 3, x + y > z}], {x, 1, 2, 1}, {y, 1, 2, 1}, {z, 1, 2, 1}] If I run this syntax I get a series of Outputs, I am trying to Count only the ...
646 views

### Labeling a grid

I have m = {{0, -1, -2, -3, -4}, {1, 0, -1, -2, -3}, {2, 1, 0, -1, -2}, {3, 2, 1, 0, -1}, {4, 3, 2, 1, 0}}; And a grid ...
95 views

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233 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: ...
396 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 ...
29 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, ...
70 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 ...
19 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 ...
54 views

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. ...
299 views

### Create Table of replacement rules

I want to create a table of replacement rules. ...
433 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: ...
462 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 ...
123 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'. ...
152 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: ...
154 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 ...
84 views

### Inaccuracy of Piecewise function? [duplicate]

I have the following issue and can't find a solution so far. ...
57 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: ...
357 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: ...
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?
586 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 ...
223 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 ...
578 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 ...
146 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, ...
312 views

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1k 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 ...
285 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 ...
206 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 ...
264 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: ...
393 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 ...
583 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 ...
180 views

### Why is Mathematica not able to calculate more digits [duplicate]

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 ...
859 views

253 views

### Adjust the opacity of the lines in a ListPlot

Here is what I am trying to plot: ...
338 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 ...
70 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 ...
417 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 ...
435 views

### Do any mainstream text editors support Wolfram Language syntax for highlighting? [duplicate]

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 ...
150 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): ...
168 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 ...
78 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 ...
221 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 ...
186 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 ...
133 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 ...
568 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 ...
306 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) ...
40 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 ...
88 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. ...
295 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 ...