0
votes
0answers
5 views

I am trying to solve a set of coupled differential equations with known boundary conditions using mathematica

Here are my differential equations and boundary condition. f''[x] = h^2/f[x]^3 - f[x] (1 - f[x]^2), h == (f[x])^2[Phi]'[x] f[0] = 1, f[L] = 1, where L can take values: {L,1,8} [Phi]'[0] = 0 I've ...
0
votes
0answers
16 views

Brevity of denoting Conjugate[]

How do I make Conjugate[] expressions have a bar above them instead of Conjugate[ before them, in order to shorted up expressions? I'm looking at something like this screenshot for example:
1
vote
1answer
42 views

Understanding SameQ

I am new to Mathematica. So I have read the documentation for comparing expressions in Mathematica and I still don't get the SameQ (===) function. Let me give you a short example: ...
0
votes
2answers
27 views

Long list of similar rules

Given the following: ...
0
votes
0answers
19 views

How to join datasets?

I have 3 datasets as a lsit: {dataset1,dataset2,dataset3} I want to convert them into a single dataset. The following does not work Join[{dataset1,dataset2,dataset3}] However, this works ...
0
votes
0answers
30 views

Random generation of three-non-collinear and four-non-coplanar points in 3D space

Please, take a look to this code. How it can be improved so that the time execution becomes smaller? ...
0
votes
0answers
24 views

Bar legend to Contour Plot

I have a set of 4 contour plots and I show them with the simple Show. How do I present a legend that is the same for the whole set? i.e., the scale needs to truly represent the set and not the values ...
0
votes
2answers
21 views

Generating a Variable Number of Dynamic Variables

I know questions that get at this very issue have been posed in other ways here, but as a relative beginner, I've had trouble understanding the answers. For my application, I am developing a simple ...
0
votes
0answers
31 views

What's real analogue for FromDigits?

FromDigits only works for integer strings. What's its real-number analogue?
1
vote
1answer
22 views

Variables within functions within DSolve

Hi I am just beginning to learn Mathematica and this is my first time I have been exposed to any type of coding. I am encountering a problem in a basic physics problem. For example we are always ...
0
votes
0answers
12 views

Can i change the default search paths?

When i try to load packages on this computer, i get an error (i already know the packages work). I think the issue might be to do with the fact that mathematica can't process the network drives, some ...
0
votes
1answer
36 views

How to use MemberQ for such Variables?

This is NOT the desired out come. I want this test to fail: ...
0
votes
1answer
38 views

Append plot to existing plot?

I have generated a plot from t=0->1, and I wish to append another plot from t=1->2. How can I do this? Thanks in advance.
1
vote
0answers
23 views

How can I detect certain letters by shape in an image?

I have a website where people can post Flipbook animations, called Flipnotes. Unfortunately, most of the Popular flipnotes are in the following categories: MV (Music Video) AV (Audio Video) AMV ...
0
votes
0answers
10 views

Insert an element to AdjacencyGraph

I'm not able to insert an element to mine AdjacencyGraph. I suppose that i should modify my AdjcencyMatrix: ...
1
vote
1answer
26 views

Finding the true expectation

I have the density function and I want to determine its expected value ...
2
votes
2answers
96 views

Too high differential order in boundary conditions?

The following boundary value problem has a unique solution: $$ \begin{cases} x''-x=0\\ x''(0)=0\\ x(1)=1 \end{cases}\\ \text{General solution: } x=c_1 \sinh{t}+c_2\cosh{t}\\ \text{Solution for BVP: } ...
1
vote
0answers
29 views

Purpose of VertexWeight

I am trying to partition a graph into partitions of equal weight (on the vertex). I looked at the documentation, and found VertexWeight, which seems to attach a weight to a vertex. In the details, ...
0
votes
0answers
48 views

How to render a 3d image of the galaxy? [on hold]

I recently came across the Uniview software package, there has even been a TED talk about it. Here is another example of some interactive views of star maps. In Mathematica 10 AstronomicalData has ...
2
votes
2answers
59 views

How to rearrange structure and type of an imported dataset?

I have a bigger dataset imported from Excel. Its elements have a form of {time, data}. Day is irrelevant and I would like to have the time in decimal form e.g. 10:30 is 10.5 ...
2
votes
0answers
33 views

Keeping Font Relative Size to Object/Graphics/Plot Object upon Reize

I want to keep the text generated within a graph/plot to remain the same relative to an element (a disk of size 0.2) of the image upon resize, not the image itself, while maintaining the original ...
0
votes
0answers
28 views
3
votes
1answer
57 views

Compability between Graphics coordinates and shifted projections in GeoGraphics

I'd expect GeoGraphics to handle positions of points since they are provided with GeoPosition wrapper. But it is not the case ...
-5
votes
0answers
20 views

Rings modulo n, units [on hold]

How many units does the ring $Z/60Z$ have? Explain your answer. How many ideal does the ring $Z/60Z$ have? Explain your answer.
0
votes
1answer
17 views

Histogram 3D: use different bin width in two directions

I'm trying to plot an histogram of a set of data, I would like to use a bin of different width in x and y direction. I've tried using the following two codes: ...
0
votes
2answers
45 views

Modular arithmetic in Mathematica? [on hold]

I want to implement something like 1 + 1 = 0; i.e., simple modular arithmetic in Mathematica. This seems like it should be a really easy built-in option, but I ...
2
votes
0answers
20 views

Why does Mathematica remember print settings?

Mathematica has a strange behavior with respect to printing and saving to PDF. It remembers the print settings, such as page range and number of copies along with the file. So if I print 50 copies ...
0
votes
0answers
23 views

I need help to solve this problem [migrated]

Let $m,n$ nenegative integers and $m>n$. Find polinom $g(x),r(x)$ from the ring $R[x]$ such that $x^m -1 =q(x)(x^n -1) + r(x)$ , $r(x)=0$ or $deg(r(x))<n$. In which case $x^n -1|x^m - 1$.
1
vote
1answer
34 views

SemanticImport unable to properly read an Excel file with accented letters

Apparently SemanticImport fails to properly import Excel files when accented letters are present in the first (header) row. I'm using Excel 2013 on Windows 8.1 x64 ...
3
votes
0answers
62 views

Numerical integration: complicated 2D integral seems to be poorly estimated

In the course of some physics research I've been working on, a very annoying integral has appeared that I'm having difficulty evaluating numerically. Any help you could offer would be greatly ...
1
vote
2answers
83 views

Permanently rounding numbers/values to a given number of significant figures

I am searching for a simple way of rounding and setting an input to a desired number of significant figures. There are a vast number of posts that discuss similar problems, but none address this ...
2
votes
0answers
54 views

Is there a notebook to create entries for OEIS?

Is there a notebook to create entries for OEIS? I seem to recall something like this a few years ago, but I haven't been able to find one. It might be from MathWorld. Any suggestions? Edit If I had ...
1
vote
1answer
33 views

Hiding a Manipulate slider

I want to generate a different random initial condition for rule 110 using a Button for Manipulate, not a slider. How can I make the slider invisible here? I tried specifying ...
1
vote
2answers
87 views

How to efficiently get a list like this?

I want a function myfun that generates list like this ...
-1
votes
0answers
31 views

Problem with control structures on getting root values on array [on hold]

Since mathematica control structures are a bit different from programming languages that I'm familiar with , I'm having problems. I want to assign the roots of a function to an array , but check if ...
17
votes
2answers
202 views

Maximize[Cos[x - 1], x] is not evaluated

No explanation needed: Maximize[Cos[x + 1], x] Maximize[Cos[x - 1], x] producing ...
1
vote
1answer
40 views

Possible to dynamically redraw single plot of multiple shown together?

I am attempting to create a tool to visualize gradient, eigenvector, and eigenvalue information for a 2D surface. I want to show a contour plot of an inputted function and overlay the gradient and ...
2
votes
2answers
106 views

Polynomial expansion of operator

I am new to Mathematica, I am trying to generate the polynomial function of a operator. So for example, the operator $L $ is $\frac{\partial f}{\partial x}+\frac{\partial f}{\partial y} $, and I want ...
0
votes
2answers
25 views

CurrentImage returns almost fully black image

On Mathematica 9.0.1.0, Windows 7 SP1 Calling CurrentImage[] returns a black image, with a few non-black pixels near the top of the image, which may be some kind ...
2
votes
2answers
52 views

Strange behavior with Show command

I enter this: ...
4
votes
1answer
77 views

Is the divergence between Round and setting an explicit precision intentional or a bug?

Introductory remark: I take it (from Mathematica's online documentation), that Precision is effectively the number of significant digits, as seen by the system. ...
1
vote
1answer
25 views

LineScaledCoordinate problem for exact coordinates

There appears to be a bug in LineScaledCoordinate I've faced writing an answer for Animate point go round a triangle. For coordinates with exact values, instead of ...
7
votes
2answers
167 views

Using map projections with astronomical data

I noticed that all important "Geoprojections" are available in projections for a spherical reference models: GeoProjectionData function; 1 - I am trying using the sinusoidal projection for ...
2
votes
1answer
61 views

ControlType -> None Vs. Module inside Manipulate (i.e. making everything local)

I'm building a program on another one made available in the Wolfram Demonstration Project. I've noticed that in the original code (working flawlessly) many variables were made local inside the ...
8
votes
4answers
460 views

Animate point go round a triangle

How can I animate a point moving on triangle sides? I can generate traingle and point but I have no idea how to define point movement. I'm guessing that I have to use sin and cos in coordinates but I ...
1
vote
1answer
39 views

How do I plot 3 (x,y,value) on a Histogram3D[] function?

I have been trying to plot data using the Histogram3D function but I've had no luck, in excel I have x, y and a value I want to plot for each pair, do I have to save this as a data file first? I have ...
0
votes
1answer
56 views

how to solve line and ellipse equations in 3D? [on hold]

I have a point and a vector to find the line equation, and ellipse equation in 3D. I need to solve the two equations of line and ellipse in 3D. how can I do this, what equations should I use?
2
votes
0answers
100 views

Proving large inequality in 6 variables

I have arrived at a very large inequality in 6 variables that I would like to prove is true. The command I have tried is the following: ...
1
vote
1answer
66 views

Preventing complex term in a differential equation solution

I am solving the initial value problem: $$y'=\frac{t+1}{t(t+4)},\quad y(-1)=0$$ I believe the correct answer is $$y=\frac14\left[\ln(-t)+3\ln(4+t)-3\ln 3\right]$$ with an interval of existence ...
0
votes
2answers
34 views

Import table from txt file with specific rows

I have a .txt file written as 1 2 3 4 5 6 7 8 9 10 11 12 I would like to import it as three matrices according to the rows. I used b = Import["d:\am.txt", {"Table", Range[1, 2]}] Seems it ...

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