1
vote
0answers
167 views

Manipulate - Flickering graphics

I am new to mathematica and was experimenting with NDSolve and doing a simple demonstration of orbital motion and Newtons laws. I put together the following code which all seems to work except the ...
0
votes
2answers
158 views

Iterating Reads From a Text File and Writing the Results of Operation

I have a very large text (TSV) file. I am able to now read single line, thanks to StackExchange. I am able to read a part of that line using the part operator. I want to iterate through the whole ...
3
votes
2answers
679 views

NDSolve: Normalizing at every step

Suppose I have an transport equation with an initial conditions: ...
5
votes
1answer
135 views

Functions, Options and Symbols

In the normal Mathematica language, where no built-in symbols are redefined and no evil things happen, is it a valid assumptions, that no function symbol (Plot, ...
11
votes
3answers
388 views

Replace operators

/. can be used to replace variables but how can one replace operators. For example in a * b, ...
8
votes
1answer
363 views

Looking for a package regarding Schur Polynomials and Kostka numbers

I'm currently looking for any Mathematica package that involves Schur polynomials and/or Kostka numbers. More generally, I'd be happy with anything that expands on symmetric polynomials in general. ...
0
votes
0answers
28 views

What is the precision of this number? [duplicate]

In a matrix evaluation, I got the following number. 2.8330574963868513` I understand that the number after ` shows the precision of the output number. But this ...
3
votes
2answers
443 views

BC for transport equation using NDSolve

First I can solve a transport equation with a source (Is it still called transport equation?) using DSolve. The form of the source serves only as an example. It can ...
4
votes
1answer
164 views

Automatically tracing and keeping ViewPoints in a list while manually rotating 3D graphics

I will need to make a video from the manual rotation of a 3D graphics. In order to do this, I will need to record the set of all view points that I made during rotation. There is method that we can ...
5
votes
4answers
1k views

Left-aligned PlotLabel?

Is it possible to have the text generated by PlotLabel (or any other function) aligned to the left side of the plot instead of in the center?
4
votes
0answers
489 views

Kalman filter by hand

I am now learning the Kalman filter and wants to implement it by hand to understand it better. To be specific I want to first simulate a sequence of data by $$ \dot x=Ax+Bw\\ y=Cx+Dv,\\ ...
15
votes
6answers
683 views

Matrix Rotation

If I have a matrix of any size, say $\begin{pmatrix} 72 & 32 & 64 \\ 18 & 8 & 16 \\ 63 & 28 & 56 \\ \end{pmatrix}$ $\begin{pmatrix} 72 & 32 \\ 18 & 8 \\ 63 ...
2
votes
0answers
358 views

differential equations with implicit functions

I have an ordinary differential equation that contains coefficient functions that depend implicitly on the independent variable via an algebraic equation. I am trying to go ahead and use NSolve to ...
2
votes
0answers
228 views

Negative power instead of fraction

Solve returns a solution in the form {{x->y/a^2 + y^2/a^7}}. Since I want to process the input (with another program) in terms of Laurent polynomials, I would ...
1
vote
1answer
102 views

Factorize and find the null space of a polynomial in several variables [duplicate]

I've been asked to factor the following polynomial: poly = 6 x^3 + x^2 y - 11 xy^2 - 6 y^3 - 5 x^2 z + 11 xyz + 11 y^2 z - 2 xz^2 - 6 yz^2 + z^3 And to solve for z so that poly = 0 Can anyone help ...
0
votes
0answers
252 views

FindMaxValue vs FindMaximum

I'm studyng the maximum value of the following function ...
-3
votes
1answer
164 views

Limit of a subsequence

I am trying to calculate limit for a subsequence <${ a }_{ {n }^{ 2} }$> because I was trying to see that limits of sequences and subsequences are both same. I was able to generate the sum for ...
4
votes
2answers
2k views

Defining a non-commutative operator algebra in Mathematica

I am trying to develop a function(s) to do some commutator algebra to compute the enveloping algebra and ideals of a Lie algebra. For example if I have $SU(2)$ algebra generated by $L_i$ ($i=1,2,3$), ...
5
votes
2answers
160 views

Speed up plot of $\sum_{j\ge1} 2^{-j}(1-2^{-j})^{n-1}$

I'm a beginner at Mathematica. I would like to plot the following function: $${n\over2} \sum_{j\ge1} 2^{-j}(1-2^{-j})^{n-1}$$ However the following code is just too slow: ...
10
votes
2answers
295 views

Determining whether two $k$-chromatic graphs are isomorphic (respecting vertex coloration)

Consider the case where I have two $k$-chromatic graphs $G_1$ and $G_2$, i.e. two graphs where individual vertices can be colored with one of a set of $k$ total colors, and I would like to determine ...
19
votes
1answer
201 views

What's the internal command for entering a fraction?

I'm looking for the FrontEnd`Foo[...]-like command that's triggered when pressing Ctrl + /. Are there any discoverability ...
1
vote
3answers
310 views

Find a single max value

...
5
votes
3answers
705 views

How to create a planar graph from a set of random points

Question Given a set of points in the plane, how can you create a planar graph in the standard graph representation of Mathematica (version 9 or higher), from these points? Background A planar ...
3
votes
2answers
382 views

How do I represent a system dynamics feedback loop?

In System Dynamics, if I want represent the relationship between Speed and Distances, I create a Flow (Speed) and a Stock (Distance) as you can see in this Insight Maker Sample . Heres an Image of how ...
1
vote
2answers
101 views

Interpolation of an upper-triangular list

I have 2d list which is upper triangular. I would like to interpolate it, but I cannot unless I set the interpolation order to 1. I tried making the list rectangular by filling the bottom half with ...
2
votes
2answers
150 views

How to find out if invisible notebooks are still open

If I create a notebook CreateDocument and I set options such that Visible -> False, is there any way to tell if it's still ...
2
votes
1answer
137 views

Round image corners [duplicate]

I just read StackExchange blog It’s OK to Ask and Answer Your Own Questions which even encourages it and decided to ask about a problem I now know how to solve. But I found an elegant answer only ...
5
votes
1answer
466 views

How to export attributes or annotations to an HDF5 file?

I'm trying to export attributes and annotations to an HDF5 file. But the documentation here is horrible and there are no examples of this. I spent some time playing, but I can't get it to work. Here ...
2
votes
3answers
205 views

Speeding up a simple simulation with random extractions

I wonder if anybody can help, I need a hand with a simple simulation I am writing with Mathematica (I am using version 8). Basically it creates a list (called l) with numbers from 1 to n and a random ...
0
votes
3answers
225 views

Cover a rectangle with size constrained rectangular regions

I have a big grid (indicated on the image in grey) that is divided in several blocks (each with a maximum width of 3 units). Now I would like to divide a region (indicated on the grid in red) by the ...
13
votes
3answers
323 views

Transform fancy usage messages in 1D string

When we look at the usage messages of built-in functions nowadays (not in the good old times, when they were a simple descriptions) we see that although they look pretty in the front end, it is really ...
0
votes
1answer
274 views

ContourPlot with parameter

I have an equation for function F[x,y]==0 which first argument x is real and another, y, ...
2
votes
2answers
662 views

Using transfer function model to generate state space model

I am trying to generate the state space model for the following system: However, the following code does not generate the state space model I expect: ...
1
vote
1answer
94 views

Plotting data that lands on the axis

I have a data point that lands right on the Y axis, which corresponds to the index of refraction of some sample. the x axis is the mole fraction of chloroform of my samples. How do I get the first ...
2
votes
2answers
390 views

Aligning Text Using Spaces While Maintaining Pretty Print

To help illustrate my problem, consider the following cell: First thing to notice is that there is syntax highlighting. Second, I can pretty print mathematics; that is, I see $x^2$ instead of ...
4
votes
2answers
338 views

Can Mathematica understand Excel dates when in number format?

I have a very large Excel file with dates in the format 2013/01/17 08:02:00 PM which is a custom date format. I have to convert this file to CSV in order to import it into Mathematica because I can't ...
5
votes
1answer
117 views

Recursion and safety of SetAttributes[Function, SequenceHold]

Compare the timings below ...
2
votes
1answer
85 views

Why the coloring in Block construct? [duplicate]

I want a function that works like in the following example: it gets an expression which contains a variable var and evaluate it setting setting var = value. I used ...
3
votes
1answer
177 views

How to replace variables in an expression?

I have generated a matrix using Mathematica, $\left( \begin{array}{ccc} \text{cos$\theta $} & -\text{sin$\theta $} & \text{cos$\theta $}\, \text{dx}+\text{dx}-\text{dy}\, \text{sin$\theta $} ...
5
votes
2answers
246 views

Better method for creating a tuple out of two lists

I just combined two lists using this method ...
6
votes
2answers
181 views

Reduce data by taking averages

I am trying to implement the following: I have got two vectors x and y of unequal lengths. The length of ...
1
vote
2answers
82 views

How to construct a new list made from a function that operates on two lists

I need to take two lists (each list contains the number of moles of a chemical). I have a function calledFraction that takes the each entry of the list and then calculates the mole fraction of ...
5
votes
2answers
199 views

How to set PlotLegend Number Format

Is there any way to make Mathematica to show the legend labels like a real number rather than in fraction form? I read the BarLegend options, however they are just ...
6
votes
3answers
497 views

Order list of monomials by degree (Pascal's Triangle)

Suppose I have the following list of monomials: {1,x,x^2,y,y^2,x*y,x^2*y,x*y^2,x^2*y^2} How could I manipulate it to get ...
4
votes
1answer
161 views

Padding plot ticks with zeros on the right

I would like to know how can I make a real-valued plot tick pad with a zero to the right of the decimal point on integer values. This is what I have: ...
2
votes
1answer
94 views

Change “Format type of new input cells” to InputForm

In Preferences -> Evaluation there is a menu to change "Format type of new input cells" and the only options available are: StandardForm, TraditionalForm, and Raw InputForm. Is it possible to set ...
11
votes
1answer
210 views

MakeJavaObject on list of inhomogeneous objects belonging to the same base class

When using J/Link, how can we create an array out of objects belonging to different classes but having the same base class? Here's an example: ...
6
votes
1answer
143 views

Using enum values with J/Link

How can I pass enum values to a function when using J/Link? What is the correct syntax for typing an enum value? For example, call normalize() using ...
5
votes
3answers
272 views

Multiply list of pure functions by list of scalars?

I am trying to write a function that returns a list of pure functions. The last step in the function, is to multiply the list of pure functions by a list of scalars (i.e. matrix multiplication). When ...
3
votes
2answers
478 views

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