Mathematical vectors, operations on vectors and vectorized programming.

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1answer
53 views

Plot a numerical integration as a function of a variable

Suppose we have a function that is hard to evaluate analytically but a numerical estimate suffices. For example consider the $f(x,\Lambda) = \Lambda\cdot \sin(x)$ where $\Lambda$ is some parameter I ...
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2answers
52 views

Plotting vectors using derivatives

This question stems from a previous question I asked here: Multiple Integral of equation including dx prime? An equation describing a gravitational field of a cuboid is given as: $V(X,Y,Z) = -G\rho ...
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3answers
57 views

Referring to the components of a vector within a sum

I feel like I'm missing something obvious here, but.... I'm playing around, trying to do the standard deviation for my stats homework (don't worry, I already worked out the answer by hand), and I ...
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2answers
68 views

Problem in matrix multiplication

I created a random directed acyclic graph using Mathematica. I need to compute a specific function from its adjacency matrix. ...
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0answers
21 views

Controlling scaling of multiple vector fields in VectorPlot3D

I'm trying to plot the electric and magnetic fields of a relativistically moving electric charge using VectorPlot3D, and apply "Manipulate" to change the velocity. The code I'm using is as follows: ...
3
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2answers
158 views

Vector Plot of a linearly varying cantilever

I want to drawing with Vector Plot a deflection and slope of a linearly varying cantilever. And with Contour Plot it works but with Vector Plot it didn't. Here is the code: ...
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0answers
20 views

Find the point of intersection of A,B,C-plane and D1D2-line

The problem. Five points A,B,C,D1 and D2 in R3 are given. (1) Determine whether three points A,B,C are collinear(i.e. lie on the same line). (2) If A,B,C are not collinear, find the plane that ...
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0answers
25 views

How do I get Mathematica to evaluate symbolic linear algebra [duplicate]

First of all, I am VERY new to Mathematica. That said...I have defined vectors as: e1=2x-y and e2=x+y (x and y are orthonormal). I also defined the dot products of x and y in Mathematica. I want to ...
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1answer
52 views

ParametricPlot3D won't show [closed]

I want to see the image of a tube made from a space curve. I define the surface using Frenet-Serret frame but the software does not show me the plot. What might be wrong with my code? Thank you.
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1answer
50 views

Error in cross product [closed]

I want to take the cross product of two rather complicated vectors but Mathematica gives me error: Here is the input: The error I get is "The expression pu cannot be used as a part specification." ...
0
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3answers
37 views

Define a function of a vector without fully specifying the components of the vector [duplicate]

I have a vector $A=\{1,2,3,4,5,6\}$, and I want to define a function of $A$ as f[A_]:=A.X where $X$ is another vector. I want to define this function without ...
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2answers
917 views

How to plot vector function r(t) = i + j + t*k

How can I plot the vector function $r(t) = i + j + t\;k$, where i, j, k are unit vectors, and t is the parameter of the function r.
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40 views

How to use the Mathematica to simplify a vector symbolic computation?

I'm working with a rigidbody dynamic problem,and I have listed the "Newton-Euler" equation for a system.The equation I listed is very long and many items are included.I want to use the Mathematica to ...
0
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2answers
54 views

Vector optimization with vector length as a free variable

I'm trying to solve the following problem: For a vector $v$ of length $c$, $\min \frac{\sum v[i]^4}{(\sum v[i]^2)^2}$ subject to $\sum v[i] = N$. I can solve this numerically for a given $c$ using ...
4
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1answer
65 views

How to use DSolve with vectors without decomposing into vector components?

Given a basic, two-dimensional ballistic trajectory problem, I can solve the equations of motion using DSolve (or NDSolve) by ...
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1answer
49 views

Interpolate a discrete vector field

I have a discrete vector field, from which I want to derive the continuous one. For example, the planar vector field is defined by: ...
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0answers
49 views

ParametricPlot3D doesn't work with components of a vector input

I can't understand why ParametricPlot3D works, when the input is a vector and does not work, when the input is separated components of the vector (it returns an empty plot). The same happens for ...
1
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1answer
26 views

Inverse KroneckerProduct given other arguments

I'm having problems working out how to do the inverse of a two argument Kronecker Product, given one of the decomposed column vectors. For example, say I have used the Kronecker Product on two ...
0
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1answer
79 views

Phase Portrait Trajectories

How do I make a phase portrait which looks like the ones demonnstrated here? Not the fancy version where I can use the controls to change it, just a screen-shotted version of say a spiral point? Any ...
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2answers
166 views

How can I express this recurrence function in Mathematica?

\begin{equation} r_{i+1}=r_{i}+V_{i}{\Delta}t \end{equation} Where \begin{equation} V_{i}=(0.01, 0.40) \end{equation} and ${\Delta}t$ is the difference in time. My implementation (this is for ...
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0answers
38 views

StreamPlot in 3 Dimensions

I would like to plot the vector equation $\left( {\begin{array}{*{20}{c}} {\frac{{ - a + \sqrt {{a^2} + 4bc} }}{c}}\\ {\frac{{ - a - \sqrt {{a^2} + 4bc} }}{c}}\\ 1 \end{array}} \right)$ as a stream ...
4
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1answer
101 views

How can I implement this recurrence equation in Mathematica?

I asked a similar question yesterday but today I realized that I was implementing the wrong function. I have tried changing the implementation but I can't get it to work. Problem: There is a river ...
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2answers
90 views

How do I do the Minkowski sum of two sets?

I have 2 sets, $X$ and $Y$. How do I find the Minkowski sum of these sets?
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2answers
63 views

Zero division in linear equation solution

I'm trying to transform a vector to another coordinate system with different root vectors. The other root vectors are defined by three points in space that form a plane, and it's a normal vector. ...
0
votes
1answer
79 views

Use ParametricNDSolve with Plotting

I am attempting to solve a differential equation of the form $$ \frac{dx}{dt}=ax+by \\ \frac{dy}{dt}=cx $$ with parameters $0<a<1$ and $a,b,c \in \mathbb{R}$. I am able to use NDParametric ...
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1answer
39 views

Vector Analysis in Version 8

Silly question. Why does Needs["VectorAnalysis`"] Grad[Sin[x^2 + y^2], {x, y}] give the error Coordinates::invalid: "{x,y} is not a valid coordinate system ...
2
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1answer
45 views

Plotting Vectors in Mathematic at lat/long positions

I have some current data that I want to plot in Mathematica. The first two columns are the latitude and longitude respectively (longitudes are negative b/c it is west of the prime meridian and all ...
5
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1answer
114 views

How to define an orthogonal basis in the right way?

I am trying to work with the vector notation without defining vector components explicitly. $Assumptions = (x | y | z) \[Element] Vectors[3] The vectors ...
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0answers
142 views

Solving Symbolically Equations with Vectors and Matrices

I want to solve equations with vector variables and vector/matrix parameters symbolically. As a basic example I would like to be able to solve something like $[I-aG]x=b$ where $a,b \in \mathbb{R}^l$ ...
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1answer
37 views

Protected Tag list and not a vector errors

I am working on a project for school, and I just need to find when the angle between a tangent vector and a line formed between two points. Here is the code I'm using: ...
6
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2answers
200 views

VectorScale Explanation

I'm having great difficulty understanding VectorScale. Here are the definitions from the documentation. With the explicit specification ...
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0answers
38 views

Problem with precision in ray tracing

today i was writing a ray tracer to find intersection point between a single ray and a cylinder. ...
1
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1answer
68 views

Mathematica error in vector element access

I have the following code, but Mathematica insists that xj is not a symbol! How may I fix that? ...
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4answers
171 views

Define Function with Sum over a list

I want to define a function that would symbolically look like $$ t(s,\underline{a})=\pi s + \sum_{n=1}^{n_{max}}a_n\sin(n \pi s) $$ (something like a finite Fourier series). Here $s\in [0,1]$ and ...
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37 views

How to solve a multi-vector optimization problem efficiently?

How to efficiently solve a optimization problem which involves multiple vectors? My optimization problem is: $\min_{\bf{K}_{i}} \sum_{i<j}\left[\bf{t}\cdot(\bf{K}_i-\bf{K}_j)\right]^2$, s.t. ...
2
votes
1answer
244 views

Inverse gradient operator

I found a nice paper about inverse vector operators here. I have successfully implemented a Mathematica function for most of them, however I can't figure out how to do inverse gradient (page 7 in the ...
0
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1answer
60 views

Weird Vectorplot

I would like to Plot a simple Vector Field, all vectors normalized to one. If i for example take a evenly distributed sample of the field and plot it with the ListVectorPlot function, i get a plot ...
2
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0answers
134 views

Extract common factor from vector or matrix

I can't believe this hasn't been asked before but I can't find anything. Is there a way to convince Simplify or FullSimplify to ...
3
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1answer
150 views

Introduction to Vectors and NDSolve

I want to use NDSolve for a complicated equation that contains vectors. I am still new to Mathematica, and have really enjoyed what I have learned thus far. Concerning this question, I have already ...
2
votes
1answer
207 views

How to control the length of vectors in VectorPlot

I want a slope field for a scalar differential equation. For simplicity I have chosen $dx/dt=rx$, where $r$ is a parameter. I used VectorPlot for the slope field as you can see from the code below. ...
2
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1answer
76 views

How can I use parts of lists with Dynamic?

I'm a newbie - what am I doing wrong? I want to use parts of lists (vectors) in calculations but Mathematica will not evaluate anything that involves parts of lists that update dynamically. Is there a ...
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1answer
80 views

How to rotate vectors in vector plot?

I'm writing an exam for my calculus students and am seeking help with using Mathematica on a particular problem. Here's my idea: I want to give a multiple choice problem that has four choices of ...
0
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1answer
140 views

Simplifying symbolic expressions involving dot products

I have a function that outputs a large expression containing dot products of vectors. None of the vector components are known, so all dot products are symbolic. For instance, part of the output may ...
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3answers
283 views

“NotAvailable” and “NotApplicable” data points returned by WeatherData[]

I am trying to use ListVectorPlot in combination with WeatherData and CountryData to show ...
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2answers
92 views

Symbolic matrice or vectors in Mathematica?

Suppose I would like to define an expression, containing and array or matrix of symbolic elements. Like this ...
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1answer
52 views

Sort a vector of vectors of vectors

Let's hope I'm calling it well, I have this vector, or matrix, now I really don't know what it is ...
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1answer
162 views

Basis for the intersection of vector spaces

The MuPAD Notebook Interface provides the linalg::intBasis function: http://www.mathworks.com/help/symbolic/mupad_ref/linalg-intbasis.html How can I get the same ...
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2answers
47 views

Exporting mixed data of matrices and vectors / lists

thank you for reading my question. I have a problem trying to export mixed data from Mathematica. I have different matrices and vectors, which should be combined to a output file. Here a ...
7
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1answer
446 views

Estimation of vector autoregressive (VAR) process

To estimate 1-dimensional VAR process (which is AR process) you can easily use functions EstimatedProcess or ...
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2answers
83 views

Returning the 3-dimensional vector from a skew symmetric matrix

I'm trying to write a function that takes in a skew symmetric matrix and returns the corresponding vector. When I write the following code, it works when I leave it as variables, but it does not work ...