0
votes
0answers
4 views

Significantly different results between Mathematica and Wolfram Alpha with large radicals and small numbers

I have some code which involves tiny numbers being put to the power of very large numbers. The function I'm looking at is $\varphi = \omega(T) \left(1 - (1 - \epsilon)^{n_{e}(T)} \right)$ when ...
0
votes
0answers
17 views

Is Eigensystem::eivin message a bug?

I noticed that in the question Request for clarification of Eigensystem::eivn message the error message Eigensystem::eivn: Incorrect number 2 of eigenvectors for eigenvalue ...
1
vote
2answers
19 views

How to write an operator that acts on pure function (to give another pure function)

I would like to write an operator oper that acts on a pure function f with an undetermined number of arguments, with the syntax ...
0
votes
0answers
9 views

CoordinateBoundsArray?

I want to use CoordinateBoundsArray but Mathematica does not recognise it. Is it a specific package that I need to explicit include, or is this just due to my ...
4
votes
3answers
38 views

Cluster numbers into n partitions so that each partitions sum is closest to total/n

For example having data data = {16, 4, 17, 10, 15, 4, 4, 6, 7, 14, 9, 17, 27, 6, 1, 9, 0, 12, 20, 8, 0, 3, 4, 0, 3, 4} I want to cluster them int 4 partitions ...
2
votes
0answers
15 views

Finding degenerate solutions to cubic equation, to find touching points in bandstructure

I have a cubic equation (corresponding to the band structure of a physical system) given by w in the code below. ...
0
votes
0answers
19 views

Show a part of the output but actually be recoverable

Is it possible to display a portion of the output without dropping the hidden data c.f. when using Shallow[], a part of the output is actually dropped
0
votes
0answers
17 views

Vectors in Time vs Value line graph

I have some data that varies with time and can be plotted on a line graph of values at irregular points in time. I'm trying to extract some trends from that graph and in doing so I want to treat the ...
0
votes
1answer
23 views

ListLinePlot partial filling

I use ListLinePlot to plot data: ...
0
votes
0answers
30 views

Does Sum calculate all terms before summing them?

After calculating the sum of a large number of large objects, using B = Sum[RandomInteger[{0, 1}, {10^6}], {100}]; I find that ...
1
vote
1answer
25 views

Same scale for all the axes in Plot3D

I can't this in the documentation. How do you force the same scale for all the axis while making Plot3d? There is BoxRatios, but ...
2
votes
2answers
43 views

How to restrict the motion of a Manipulate-generated Locator along a line?

If one uses a stand-alone locator and needs it to only be movable along a curve, say, defined by a function f[x], one can use a simple construct: ...
1
vote
0answers
30 views

Graphics3D bug in Mathematica 10.1 64bit Home Edition - Windows 7?

Please confirm if you face the same issue in your system... (In gnu-linux it is working fine) Notice the right and bottom lines - they appear for some reason in every ...
0
votes
1answer
26 views
0
votes
2answers
41 views

Draw a vector with mathematica [on hold]

at the risk of being trivial I would like to draw the vector $\vec{AB}$ where $A$ an d $B$ have the coordinates $(1,1,1)$ and (1,-1,2) respectively.
3
votes
1answer
89 views

Using function to transform a list

I have a list like that: {{Integer,String},....}, integer ranges from 1 to 900 and String "I" to "IV". And I need to find which pair of {x,y} each sublist is related to, so i can get a new list like ...
1
vote
2answers
66 views

Extracting points from the MeshFunctions of Plot3D

I am trying to extract the points from the mesh lines of a 3D plot. (Not my actual function.) ...
0
votes
0answers
11 views

Probability clarification [migrated]

Consider the reading habits of the X class. If we know that 30% of the class students read USA Today daily, 40% read Salt Lake Tribune daily and 10% read both of them daily, what is the percentage of ...
1
vote
1answer
35 views

Increasing Plot3D speed when plotted function is Eigenvalue

This is probably a really simple fix, but I'm fairly new to Mathematica and am not sure how to do this properly. I know that trying to plot eigenvalues directly can be computationally expensive, so ...
0
votes
0answers
41 views

Character Encoding Method

I want to identify the character encoding of a text imported by Import method by example. I would like something similar to ...
10
votes
10answers
308 views

Count the sequences in an array

Is there a short and easier way to count number of sequence in a list? Let's say I have three lists: list1 = {0,0,0,0,0,0,0,1,1,1,1,1,0,0,0,0,0,0,0} ...
0
votes
1answer
53 views

Assigning values to variables with subscripts

I'm wondering if there is a way to assign values to variables with subscripts. I have the following Manipulate function: ...
2
votes
0answers
45 views

Graph, overlapping vertexlabels

The graph I create is based on more then 1000 different word-combinations. A example looks like this: text = {{word, word1}, {word1, word2}, {word1, word3}, {word,word4}, {word,word5}, ...
3
votes
2answers
50 views

How to control when NDSolve is called inside Manipulate

Let's say I have a function which returns the resulting function of a differential equation solved by NDSolve: ...
1
vote
0answers
53 views

Improve speed of evaluating a sum over four indices

I am trying to implement the Fox-H function with several variables as sum of residues. I have arrived at the following function; ...
2
votes
1answer
115 views

Solving a system of weird equations

I'm trying to have Mathematica solve a system of equations for a friend's work in Computer Vision. I'm essentially going in blind to this and am not very familiar with Mathematica syntax, so would ...
1
vote
1answer
95 views

Using codes to replicate drawing tools in Mathematica

This might seem very obvious but I'm on the verge of losing all the annotations I've made on a graph because I can't figure a way to save it after using the drawing tool to add a few extras to the ...
2
votes
3answers
46 views

Infinite Expression Error NDSolve

I'm trying to figure out why I am consistently getting an infinite expression error when I'm trying to solve this DE using NDSolve. Any help will be appreciated. ...
1
vote
2answers
41 views

Deleting a line from a file

I'm writing a Mathematica script that writes output to a file every 10min as backup. However, I'd like it to overwrite the previous content so as not to use to much storage. Is there a function for ...
3
votes
2answers
80 views

Positioning axes labels

I need to change the position of my axes labels such that the y-axis label is in the middle and parallel to the y-axis. I'd also like the x-axis label to be in the middle of the x-axis rather than ...
-3
votes
0answers
33 views

measure theory : Lebesgue measure [on hold]

let E subset of the IR ..if m*(E)=0 then m*(E^2)=0 E^2={ x^2 : xεΕ } can you give me a hint please? Blockquote
3
votes
2answers
48 views

Keeping a plot fixed as one parameter changes in Manipulate

In the following code I'm plotting the contour $f(x,y)=0$ as well as the family of lines $y=mx$: ...
0
votes
0answers
24 views

Reset Options to Default [duplicate]

It is straightforward to set the options of a given predefined function. E.g., SetOptions[ Interpolation, InterpolationOrder->1] I would like to know if there ...
1
vote
0answers
22 views

How to access timings of each individual test in a TestReport?

I want to know how long each VerificationTest took to complete in the test report, so see which one was the longest and do some statistics on them: ...
3
votes
1answer
37 views

Contourplot fails to plot x==0 if plot range is from 0

The simple command ContourPlot[x == 0, {x, 0, 1}, {y, 0, 1}] fails to plot the line x==0. However If I add a small buffer it ...
0
votes
0answers
29 views

NDSolve There are fewer dependent variables, {V[S,t]}, than equation

I am trying to solve the BlackScholes PDE for Barrier option. It works fine for european barrier, but errors out on american boundary condition ...
2
votes
2answers
36 views

Join data imported in different variables [on hold]

I've imported data from Excel into several variables and I would like to join all data in one "big" variable. I seem to have a problem when one variable contains numerical data... ...
0
votes
1answer
53 views

Plotting the tangent of a curve [duplicate]

I'm new to Mathematica and this is probably child's play for most people, but I wanted to know how to plot the tangent of the function below at the point e=1/4 : ...
3
votes
1answer
28 views

Manipulate with a function as a parameter

I'm trying to make a Manipulate command to plot the contour lines of a function of two variables $f(x,y)$. I think I should use the "InputField" option somehow, and I thought of something like this: ...
0
votes
0answers
27 views

R^2 values for piecewise regression

So I've used NonlinearModelFit on a Piecewise function and gotten a nice little piecewise regression. This is what my code looks like: ...
0
votes
1answer
57 views

Removing imaginary and negative results from Solve

I have been trying to solve a series of equations that I know have real positive values for the unknowns (they all have real world analogues and they are not linked to a frequency domain) but despite ...
11
votes
1answer
417 views

What function generates random numbers in a compiled function?

I am writing a simulation for 2D random walk. I wrote several version of code, and found that the speed is like this (fastest to slowest): C++, Mathematica compiled procedural code, Mathematica ...
2
votes
2answers
118 views

MaxValue of a periodic function

I want to find the maximum of a periodic function on the interval [-Pi,Pi]. What I tried is the following: ...
8
votes
0answers
77 views

Dataset vs an association of associations

Associations with a record structure (e.g., a flat table) can be organised in one of two main ways. First as a list of associations, which is also used in the case of Mathematica's data set ...
6
votes
3answers
170 views

Limit of Nested Radical $\sqrt{1+\sqrt[2!]{2^2+\sqrt[3!]{3^3+…}}}$

I want to find limit of infinite nested radical $\quad \quad \sqrt{1+\sqrt[2!]{2^2+\sqrt[3!]{3^3+...}}}$ but I don't know how to define this expression in Mathematica. How can I define it and ...
0
votes
0answers
32 views

Constrained optimization and contraints expressed in terms of other variables [on hold]

I do have constraints 0 <= x <= 1 && 0 <= y <= 1 && 0 <= z <= 1 which I wish to change to ...
1
vote
1answer
52 views

Multiplying three matrices does not give expected form [on hold]

I'm having lectures on analytic geometry. I've learned that there is an associated matrix multiplication for a quadratic form: $\quad \quad \left( \begin{array}{ccc} x & y & 1 \\ \end{array} ...
1
vote
1answer
58 views

Adding letters and numbers to create a variable name [duplicate]

Let's say I have several variables, named R1, R2 and R3. I wanted to have a function ...
5
votes
1answer
181 views

Need help with the Lagrange multiplier method

Well I am new to Mathematica and got really stuck solving this problem. In class, I was ask to use the Lagrange multiplier method to find the maximum and minimum value of $f(x,y) = x^2+y^2$ which ...
1
vote
1answer
65 views

Demonstration Confusion

What is the proper way to open a Demonstration in Mathematica so that the code is visible and can be evaluated from the Evaluation menu, as though I had created it myself? Explanation: When I ...

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