1
vote
1answer
33 views

Working with tensor algebra

My question is really easy for experienced users. In my tensor equations I have an unknown tensor Q (symmetric and traceless): $Q=\begin{pmatrix} n1(x,y) & n2(x,y) \\ n2(x,y) & -n1(x,y) ...
1
vote
1answer
39 views

Vertex sizes scaled by vertex degree?

Is there any way of scaling the sizes of the vertices of a network proportional to the vertex-degrees of the vertices in Mathematica? Thanks.
0
votes
1answer
44 views

Unexpected result: Numerical and analytical results do not match! [on hold]

I am calculating the eigenvalues and eigenvectors of a matrix. This is my code: ...
3
votes
2answers
65 views

Expected area of random triangle

I want to check the following theorem by using Mathematica: $\textbf{Theorem} $. If three point $P,Q,R$ are picked independently at random in the triangle $ABC$, than expected value of the area of ...
2
votes
0answers
51 views

Strategies to compensate for lack of multi-document interface?

I use Mathematica (Home Edition) to manage notes which live in a large number of different notebooks. In my case the notebooks (hundreds) are just organized using document names and file system ...
0
votes
0answers
21 views

Question about # Symbol [duplicate]

I am trying to solve an equation and the solution includes # symbols. I read up on them but can't understand how they are related to my solution. I solved a simple trigonometric equation of third ...
-1
votes
1answer
36 views

Plotting a function of another function

Edit: So I have several functions which come from other functions. For example: ...
1
vote
2answers
44 views

Selecting points in list that are inside a contour [duplicate]

I have a list of points which form a closed (connected) contour or path in two dimensions. I would like to get all points from a second list which satisfy the requirement that they are inside the ...
-4
votes
0answers
50 views

NOT Mathematica Integration

Why integration is not found, please help me Integrate[Exp[Pi t - (Pi r^2 Hypergeometric2F1[1, 2/b, (b + 2)/b, t^(-b/2)/A])], {t, 0, r^(1/2)}] Thanks in ...
2
votes
3answers
134 views

Distance from point to line [duplicate]

I'm a newbie with Mathematica and I managed to draw a line and a point in 3D on a graph ...
5
votes
1answer
175 views

How to find giant component of a network?

Is there a specific command in Mathematica 9 or 10 to extract the largest component of a given network which has one large and many small components? The ...
0
votes
1answer
65 views

How can i 2d-plot Cobb-Douglas function?

can I plot Cobb-Douglas function in 2D without using ContourPlot? I have this function: u[x1_, x2_] := Log[x1] + 2*Log[x2]; and now I plot it using: ...
1
vote
0answers
76 views

DeleteDuplicates [on hold]

After having applied "DeleteDuplicates" to a list of data (15000 rows per 3 columns), when I try to interpolate that list of data it gives me back again: "There are duplicated abscissa points in.." ...
0
votes
0answers
23 views

Is it possible to get the error estimates of predicted values computed by FindMinimum using the Levenberg Marquardt method?

I use the LevenbergMarquardt method of the FindMinimum function to minimize a residual function (mathematical-optimization). This residual function is computed from experimental data and the solution ...
5
votes
1answer
103 views

Noise filtering in images with PCA

I have a stack of images (usually ca 100) of the same sample. The images have intrinsic variation of the sample, which is my signal, and a lot of statistical noise. I did a principal components ...
0
votes
1answer
41 views

How To extract data to plot it from a log file

i want to extract out the data (number) from 'geometry step' and 'total energy' in form of list to PlotList[] it. this is the Log file data log Abstract the Total ...
4
votes
5answers
284 views

Faking MoleculePlot for compounds where it isn't available

Mathematica's ChemicalData has a lot of useful information, but many compounds only have flat 2D structure diagrams rather than the cool 3D ...
-1
votes
0answers
74 views
2
votes
0answers
43 views

How can I bypass the limitations of init.m?

In a series of QA it has been pointed out that init.m suffers of heavy limitations (see as example, Automatically load packages at startup or Why can't I import ...
2
votes
2answers
56 views

How to simplify a differential equation?

Now I get a differential equation like this: (-1 + x) (1 + x)^2 == (2 (1 + x^2) (1 + x^4))/(-2 x (1 + x + x F[x]) + (-1 + x^3) F'[x]) I want to get the standard ...
2
votes
3answers
161 views

Mathematica Integration Problem

I am new user of Mathematica. Can anybody help me to solve this integration? I really needs your help. Integrate[(1 - (1/(1 + A x^(-ao)))) x, {x, 0, r}] Can not ...
3
votes
3answers
208 views

Get the coefficient matrix from a quadratic form

Suppose I have a quadratic form of qf = a x^2 + b y^2 + c z^2 + 2 d x y + 2 e x z + 2 f y z How can I easily to get the symmetric matrix A, such that ...
2
votes
0answers
24 views

Change position of data labels in BarChart3D

What would be the easiest way to manipulate the position of the chart labels in "Grid" layout in a BarChart3D? For example: ...
0
votes
0answers
41 views

Replace every power of $e^{i\theta}$ with $z$ [on hold]

If I have the expression $\frac{1}{13-\frac{5}{2} i \left(e^{-i \theta }-e^{i \theta }\right)}$ and I want to replace each $e^{i\theta}$ with $z$, so that the result is ...
0
votes
0answers
62 views

Plotting function described by other functions!

I want to plot and manipulate my VS function which comes from the other functions above it. So, what should I use in order to draw my function considering that it is described by other functions. I ...
0
votes
0answers
35 views

Check if interpolated function passes through a specified region

Is there an efficient way to check if a curve that was obtained as an Interpolating Function (from solving differential equations numerically) passes through a given region? I am solving for two ...
3
votes
3answers
166 views
1
vote
0answers
18 views

Palette Sizing Options

I am writing a palette to work with units on Mathematica 9, using just PasteButtons, and have a Button map that works as I want it to, but the formatting of the palette itself is giving me issues. I ...
3
votes
5answers
103 views

ListPlot with colors

Let's create some sample data n = 100; d00 = Table[{RandomReal[{-1, 1}], RandomReal[{-4, 4}], RandomReal[{-1, 1}]}, {i, 1, n}]; Now I want the following: create ...
2
votes
1answer
51 views

Solving a big number of non linear equations

I have three trapezoids. The first sharing its upper side (I will call b_{i+1} in the code) with the second, the third sharing its lower side with the upper side of the second. All shared sides are ...
1
vote
1answer
55 views
2
votes
0answers
39 views

ColorBars or PlotLegends for ElementMeshSurfacePlot3D

I want to produce a colorbar legend to the output from ElementMeshSurfacePlot3D (Mathematica 10). The pde was solved using NDSolveValue (FEM pdesolution is the resulting interpolating function) over a ...
0
votes
0answers
31 views

How to speed up Solve command in Mathematica 8.0?

I have two complicated mathematical functions $f(s)$ and $g(M)$ that are complicated functions of $s$ and $M$ respectively. I would like to solve the equation $f(s)=g(M)$ in order to plot $s$ vs. $M$. ...
0
votes
1answer
32 views

Export list entries under a certain condition without using loops

I have a big list that contains many 3D- chains (set of points) and for each of them a polynomial. So the structure of my list is for example ...
1
vote
0answers
61 views

Distinguish hashtag # operator when using multiple functions [duplicate]

I would like to do this list = Append[list[[#]],Map[list2[[1, #]] & , list[[#, 4]], {2}]] & /@ Range[Length[list]]; But I would like to substitute ...
-1
votes
0answers
59 views

How to find a root for an integral equation?

I try to find numerical solution $E_f$ to satisfy the following equation: ...
0
votes
0answers
59 views

Trying to create a model and manipulate plot

I have been trying to learn mathematica to implement financial models in it. However, I am still very inexperienced in this :) Currently, I have what is presented below but I can't figure out why it ...
7
votes
2answers
352 views

How to measure the slit size from given image using mathematica?

I want to measure the size of the optical slit from the microscope image. Here is the image. The dimension of image data is {1300,1030} and the real pixel size is 6.7 micron. But the problem is ...
0
votes
1answer
53 views

NDSolve with coupled ODE's and unknown singularities

I have two coupled ODEs that I am trying to solve numerically. It appears that there is a singularity in the solution to the equations which I am unsure how to get past. Both functions $\alpha$ and ...
2
votes
1answer
39 views

Translate Tick Marks

The code below creates a StreamPlot for a nonlinear system of first-order ODEs: $\dot{x}=y,\dot{y}=x+\tfrac{1}{4}x^{2}$ I have created a simple zoom slider that expands the region about the critical ...
1
vote
4answers
128 views

Implicitly inverting a function from numerical solution

I have the following piecewise continuous function: ...
2
votes
2answers
59 views

Integral invoving product of Whittaker functions

I'm trying to evaluate the integral $$ \int W_{0,a}(x)\,W_{1,b}(x)\,\frac{dx}{x}, $$ where $W$ denotes the Whittaker $W$ function, and $a,b\in[0,1/2]$. Using the Whittaker differential equations that ...
0
votes
1answer
22 views

How do you collect trigonometric functions in a polynomial?

I have an expression that has various forms of Sin and Cos and I want to collect them specifically so that I can make substitutions. As you can see I cannot figure out how to separate i Cos[theta] ...
-7
votes
0answers
14 views

Help in finding Probability distribution table [on hold]

A discrete random variable X has probability function given by f(x)= k x^3 for x=1,2,3,4. Then find a. Value of k b. Probability at x=2 c. Mean of X d. Variance of X e. Probability distribution ...
2
votes
3answers
114 views

How to obtain this expression in terms of real functions

I know that this expression (2 (ArcCot[E^(-((I ϕ)/2)) r] + ArcCot[E^((I ϕ)/2) r]))/π is real, because is the sum of a real series, in particular: ...
1
vote
1answer
38 views

Plotting a data of protein diffusion trajectory [on hold]

I have a set of data points of protein diffusion in x-y plane. They are sequential in time i.e, recorded at regular intervals of 20ms. Now, I need to plot a line plot in 2 dimensions, which connects ...
-6
votes
1answer
43 views

Plot values of parameter [on hold]

Noob-alert: I have a Mathematica notebook with a lot of engineering formulas and several inputs. I want to plot one of these formulas as a function of one of the inputs. The formula in question is ...
-2
votes
0answers
14 views

how to calculate point after rotation [migrated]

I have basic square with width 36 (red) I'm rotating square by XYZ degrees ... in example there is 45 degrees black square is rotated by point 0,0 green square is rotated by center of sqare 18,18 ...
0
votes
1answer
34 views

Importing data from a MATLAB file to MATHEMATICA [on hold]

I have been trying to import some matrices from MATLAB to MATHEMATICA. The matrices are the output after I run the MATLAB file. I had saved that file in .MAT format and trying to import it in ...

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