# All Questions

135 views

### finding an argument of a complex number

What is the simplest way to find the argument of the following function? ((1 - E^((I π (1 - α))/(β - α)) z)/(1 - E^(-((I π (1 - α))/(β - α))) z)) as I tried the ...
137 views

### Another MoebiusMu question

When I evaluate the Mertens function to infinity: NSum[MoebiusMu[k], {k, 1, \[Infinity]}] I get -1, but I expected to get -2. I wanted to modify the ...
639 views

### How can I make a Plot over a discrete set of domain points?

I want to plot the function $y=2^x$ at the $x$-values given by Table[Prime[n], {n,20}] How should I write the plot function? Like so? ...
586 views

### How can I create a 3D FilledCurve object?

FilledCurve can create a 2D graphics object; for example: ...
249 views

### What are Root objects with multiple polynomials?

In Mathematica 9 a new flavor of Root object with multiple polynomials was introduced. For example, ...
334 views

### another way to do this mapping of a two argument function

Sorry, I'm just starting to learn mathematica. I have the following two-argument function: h[{x_, y_}] := x ^ y When I do the following: ...
432 views

### Remove linear trend from data

I have a large data set with 150k lines and two data columns. I noticed that there is a linear trend, which I want to remove. So, I do the following: first fit with a linear model ...
374 views

### Linear regression in a chosen range of points

Hi I'm absolutely newbie in Mathematica and have following problem: My list looks like {{50, 0.75}, {51, 0.76}, ..., and I want to choose a range out of my ...
245 views

### Why do Plot and ListPlot use the last PlotStyle when only one thing is plotted?

When a list of PlotStyles is given, ListPlot behaves as expected when there are multiple things to plot: ...
315 views

First I have ...
113 views

### RSolve gives a Context::ssle error

I want to solve the following recurrence equation RSolve[{(k + 2) c[k + 2] q^(k + 1) - c[k] == 0}, c[k], k] During calculation in Mathematica I get this ...
83 views

### ShowSelection color

The color of a selection is controlled by the operating system. E.g., enter the following code in separate cells. ...
131 views

### Is it possible to make v9 ignore case when completing names?

In v8, I could type, say, fulls or texf to get FullSimplify or ...
462 views

### Numerically solve 2nd order differential equation with singularity

Consider a second order differential equation with a potential that diverges at some generic value in the variable. For example: $$-y^{\prime\prime}(s)+\frac1{\mathrm{cn}{(s\mid k^2)}}y(s)=0$$ where ...
138 views

### Conditionals slower than operators?

I want to make my application faster. I tried to replace an If condition with operators. The If condition is ...
209 views

### Mismatch between Axes -> True and Frame ->True

Using Axes -> True of the following........ ...
1k views

### How to find major color in a picture?

I want to find the major color (the color which appears most often) in a picture and do some analysis later. For example, if I have this picture: What I want to do is find out that gray, red, ...
182 views

### Output precision

I've solved some equations using FindRoot and then computed some values. Now when I print the output, I only get a certain precision {{0.01, 496.983, 61.3147, ...
129 views

### How do I expand StirlingS2[n, 10] in terms of elementary functions?

I know that it is possible to expand StirlingS2[n, 10] in terms of elementary functions of n. I tried ...
138 views

### Outputting a set of graphics 3D objects with positions defined by one array and colors by another? [duplicate]

I have a set of 2- or 3-space coordinates in an array, $(v_1,...,v_N)$, and an array of RGB color values (outputs from ImageValue[]) for each coordinate, $(c_1,...,c_N)$. How can I output a ...
819 views

### Detection of horizontal lines in an image

Ok I'm trying to detect horizontal lines in an image. But the problem is that the line is quite obscure. So I'm not sure if it is even possible to extract that. I tried many different filters, but ...
109 views

### Prevent Suppression of Superscript 1 in Print

I'm trying to print Christoffel symbols of the second kind for a surface in $\mathbb R^3$. I currently am using something along the lines of ...
203 views

### What causes strange line artifacts to appear in plots with certain PlotRanges?

I have seen this strange plotting artifact occur before and I was able to make it go away by changing the PlotRange. However, this time I need the prescribed PlotRange to be what I define and I get a ...
569 views

### Solve for the intersection point of 3 surfaces

Basically, I have three 2-torus (tilted) in 3-dimensional Euclidean space. They are expressed by parametric equations: ...
279 views

### Why do I get empty graph when adding 'Abs' function?

Can someone be so nice to provide some help for this particular situation? I try to plot a graph of a derivative which contains modulus. Without it the graph is drawn correctly: But when I wrap the ...
397 views

### InverseSeries of multiple variables and multiple equations

CONTEXT Let us consider a bit of the Universe in which we draw spheres (see a high resolution image here). Astronomers have shown that the density within these spheres could be predicted quite ...
247 views

### CharacterEncoding failed when Import or Export as pdf

folowing is the content my test nb File: pdfTest.nb, contain some chinese characters: SampleCode1:pdf输入不正常。 After Save as or Export, pdf file looks well for the ...
358 views

### “Strange” behavior of Rule

According to the Help lhs->rhs evaluates rhs immediately. How to understand the output of the following code? ClearAll@x; {1, 3.5} /. x_?IntegerQ -> {x} ...
132 views

### Creating a number station [closed]

This is a question about manipulating sound (wav files). The goal is to produce something that sounds like a number station broadcast, see e.g., 4:00 in http://www.youtube.com/watch?v=EdnoAJ7KoFE It ...
403 views

### How to flush machine underflows to zero and prevent conversion to arbitrary precision?

I'm working on some pretty intense computation in Mathematica; when my code started running slowly, I tracked the source of the problem to Exp[]. I need to ...
882 views

### Evaluation of a triple sum does not finish in reasonable time

I'm trying to compute the following triple sum, but no result is produced within a reasonable amount of time. What to do? ...
133 views

### StepMonitor not working inside ParametricNDSolveValue

Here is a toy example: ...
1k views

### How to define a polynomial/function from an array of coefficients?

I have the coefficients of my desired polynomial in an array CoefArr (I'm new to mathematica, so I think of everything as arrays, it is actually a list I believe) starting with the constant at index ...
106 views

### Putting a matrix inside function

I want to fit a function to some data and inside the function there's a list here's my data ...
926 views

### Equivalent of MATLAB's “hold on” function

I'm making an animation where the number of iterations is known. I tried using Dynamic, as I prefer updating in real time over generating data before plotting. I ...
294 views

### Drawing Cylindrical Segment with Graphics3D

For a visualization I need a combination of 3 Cylindrical segments to visualize the incident, reflected and refracted beam of light at a surface. I got as far as the following code. ...
141 views

### Why is this code in functional style is slower than procedural style?

I know that in Mathematica a functional programming style is often more efficient than procedural style programming using For loops. But the code shown below seems ...
476 views

### How can I return the color at a coordinate in an image?

I have an imported and cropped image: TestPicture = Import["filepath.jpg"]; TestPictureCropped = ImageCrop[TestPicture, Min[ImageDimensions[TestPicture]]]; How ...
91 views

### Why will my plot not generate my entire plot?

I am trying to plot a sum of multiple HeavisidePi functions. A typical example would be something like this: ...
115 views

### How do I access the binary matrix underlying an EdgeDetect output?

Applying EdgeDetect to an image generates a black and white edge-detected image, which I suspect corresponds to an underlying binary matrix. How can I access this ...
455 views

### How can I define a function which is the sum of other functions?

I have a function which is summation of another function over different i,j iterators. U[r] = Sum[V[r, i, j], {i, 1, 5}, {j, 6, 10}] and ...
561 views

### Finding max, min, and closest root of two dimensional data

I have some data that is two dimensional (traditional (x, y) format) as so: var = {{x1, y1}, {x2, y2}, {x3, y3}} I would like to search through that large list ...
829 views

### Multiplying two dimensional data by a constant

I have a list of lists of the form: {{1, 2}, {2, 4}, {2, 8}} But I want to multiply only the second dimension of that data by a constant. I know I could do this ...
955 views

### How to compare power towers in Mathematica?

First I tried it directly, but it overflowed: ...