# All Questions

10 views

### Getting RandomChoice to work in Manipulate function

I'm a beginner mathematica programmer and I am tryin to create my first demonstration. This code should represent what happens if one changes the size of the reading frame, calculating the nucleotide ...
23 views

### HoldForm does not Hold Form for fractions sometimes

I'm facing a strange behavior of HoldForm. I need to display 1/2*3/4 in LaTeX like this : $$\frac{1}{2} \times \frac{3}{4}$$ ...
32 views

### Obtaining the relations of variables using diagonal matrices

I know this is too an elementary question, but I am a pathetic newbie in mathematica and I cannot find any answer by googling. What I want is obtaining some relations of unknown variables using their ...
89 views

### Generate nonoverlapping random circles

I want to distribute n circles unformly in an area(e.g. free plannar space). The circles could touch each other but cannot overlap. ...
30 views

### WorkingPrecision causes issue in the NIntegrate

I really can't figure out why my code sometimes is not working. My integrations involve two variables (k and kz). The integration range for both of them are from zero to infinity. I found out that in ...
35 views

### Alternatives to FiniteElement as Spatial Discretization Method for NDSolve

Finite Element Programming: [...] It is possible to skip this section and continue with the discretization stage and make use of the initialized data structures ...
20 views

### Error message with RegionPlot after SetOptions

I get an error message with SetOptions[RegionPlot, ImageSize -> Medium]; RegionPlot[u v (1 - v) >= 10, {v, 0, 1}, {u, 0, 100}] that says ...
79 views

46 views

### Solve with limit over multiple variables

Very new to Mathematica so apologies for what is probably numpty question. The following returns no solutions. However, there is a solution! If I set a = 1 I get the solution b = 1/2. Can you explain ...
41 views

### Why does NMaximize does not follow the constraints that were given to it?

(someone may want to mark it as a duplicate, but I still have to ask! I just can't figure out why!) ...
41 views

### ImageResolution Doesn't Work!

The code below is supposed to generate a high resolution plot, but it does not! g = Plot[Sin[x], {x, -1, 1}]; Export["c:/sin.jpg", g, ImageResolution -> 600] ...
118 views

### Sinusoidal Wave over a Circle

A sinusoidal wave can be plotted in a two dimensions. Generally and simply : y[x]=Sin[(2pi/lambda)x] As it is being plotted, the horizontal axis (as a straight ...
148 views

### Truncating a list once all members of a set have appeared?

Consider if you would the case where we have some list of elements: list0 = {54, 4, 7, 9, 3, 54, 4, 20, 2, 456, 2, 3}; And we have some target list: ...
32 views

### Sum of two Piecewise functions give wrong vector

I would like to calculate the normal at a certain point of a parabola. The parabola is defined only on a certain area according to a Piecewise function. Afterwards ...
29 views

### Substitution breaking the scope

A novice's problem, perhaps: it seems that /. substitution does weird things to the scope. ...
26 views

### How to share numbered variables between kernels

Supose I have two variables v[1] and v[2]. I used: SetSharedVariable[{v[1], v[2]}] Then, ...
51 views

I'm interested in buying a "Home Edition" license for Mathematica, but there's the following information which I'd like to know beforehand and which I cannot find online: As I'm about to buy it, the ...
67 views

### Substitution in parameters to “Which”

Why in this expression ...
28 views

### Which operations preserve digit precision?

Imagine I had to use numbers with a 600 precision digits. Do all mathematical operations, like +,-,...
58 views

### Two dimensional high oscillated numerical integral

I have some problem with two dimensional integral. I want to calculate such integral. ...
56 views

### How to combine several plots with this special alignment? [duplicate]

How can combine different plots just as shown in the image? Just give codes about one example plot,and tell me how to create plots as the form as gaven. Follows are codes: n = 2; z = 200; [Alpha] = ...
42 views

### How does NSolve return? [on hold]

I have purposely made 2 functions which do not have real roots. For the first function, NSolve gives me back an empty list which is correct. But I don't get why for the second function, NSolve gives ...
40 views

### HEALPix grid on a sphere

Are there any Mathematica tools for using the HEALPix ( Hierarchical Equal Area isoLatitude Pixelation) grid on a sphere? It is commonly used in astronomy, but I have not found any Mathematica ...
109 views

This a computational challenge, to find an efficient algorithm to discover a quadruple $(n,n+1,n+2,n+3)$ with the same sum of prime factors as described in the MO question, "Ruth-Aaron triples, etc." ...
47 views

### The problem (time) caused by ?NumericQ

In here, I asked a related (similar) question. Using ?NumericQ seems have slowed down the entire calculation. But I now have a more serious problem: ...
55 views

### Expressions containing globally undefined symbols inside a function where they are defined

Consider the following code. f[a_,b_]:=x; Clear[a,b]; x=a+b; f[1,2] It returns a+b. However, from a certain viewpoint, one ...
28 views

### Nested list element at position specified by a list

I'm trying to avoid constructions like Y[[X[[1]], X[[2]], X[[3]]]]. That is we have a nested list (Y) of depth $n$ and another ...
35 views

### Exctrating data information from a file.txt

I really did previous long search in the site and I couldn't find any answer that might help me. So I am asking it. I have the following data set, ...
73 views

### How discretize a region placing vertices on a specific non-uniform grid

Given a generic region, for example: \[CapitalOmega] = ImplicitRegion[ 2 x^2 + 3 y^2 + 2 x y - 2 <= 0 \[And] x^2 + y^2 > .1, {x, y}]; and a ...
42 views

### Data-Analysis and optimization [duplicate]

I have the following set of data, I want to write a program that will reduce the list on each set by, division of 100 and keep the maximum, don't divide the maximum. a = {{{2, 3, 1, -3, -5, 2, 6, -1, ...
38 views

### ConversionRules and style inheritance

Take the LaTeX-Article stylesheet stylesheet = FileNameJoin[{"Article","LaTeX-Article.nb"}]; Compare these outputs ...
119 views

### RegionPlot from NDSolve

I am having quite a headache using RegionPlot to see the region of acceptance of certain coupled differential equation. I shall elaborate and try to be as ...
60 views

### Exporting graphic to pdf acting funny

I have a plot created in a notebook that I usually would right click on and choose Save as pdf. It worked fine until this morning. Shown below, the first plot is what I used to get. The second plot is ...
143 views

### How to cut a thick curve in half lengthwise?

Is there any easy way to cut a thick curve in half lengthwise? Example: suppose I have the cardioid shown in the figure below, is there a way to delete either the inner or the outer portion of the ...
103 views

52 views

### Plot a table of functions with different color [duplicate]

I have a function with two independent variables: SNR[t_, f_] := 20 Log10[1/(2 Pi f t)] And I have a list for "t" ...
92 views

### Complex Integration

There are some sequential functions: ...
32 views

### How to show “AxesLabel” when “Frame -> True” [duplicate]

I'm using Mathematica 9.0.1, and using "LogLinearPlot" function. My problem is when I enable the "Frame", and set "AxesLabel", the labels won't be shown. If I disable the "Frame", the labels are ...