Mathematical vectors, operations on vectors and vectorized programming.

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How to export a vector of vectors (Mathematica 8)? [on hold]

I would like to export the object type: { {{"a", "n", "y"}, {"a", "s", "k"}}, {{"b", "y"}}, {{"d", "a", "t", "e"}, {"d", "a", "y"}, {"d", "r", "y"}} } and then ...
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36 views

Use Solve on a column vector while taking the derivative

I have the vector Y defined below. I would like to solve for $\frac{\partial Y}{\partial cd} = 0$. If I execute Solve[D[Y,cd]==0,cd], Mathematica runs for a long ...
3
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1answer
119 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
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1answer
152 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
60 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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0answers
11 views

Change of co-ordinate frame [migrated]

Hi Can someone help me with this question. Say point P and u, v, w are three orthogonal-normalized vectors whose co-ordinate are: P = [Xp, Yp, Zp], u = [Xu, Yu, Zu], v = [Xv, Yv, Zv] and w = [Xw, Yw, ...
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1answer
51 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 ...
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1answer
54 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
252 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
77 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 ...
2
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1answer
49 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
120 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
40 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 ...
6
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1answer
362 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
52 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 ...
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3answers
48 views

`Solve` with variables as single vector

Say I have a set of equations where the unknown variables are the elements of a vector $c=(c_1,c_2,\ldots)$ and want to solve it for $c$. Is there a way to do this with ...
3
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1answer
119 views
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0answers
71 views

Manahalobis distance between two vectors

I want to calculate the Mahalanobis distance between two vectors that represent two points. For example: ...
3
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2answers
166 views

Simple Plot of Vector

I have a vector $<x(t),y(t),z(t)>$ constrained to a unit sphere. I am trying to plot what the vector looks like as time progresses. What would be the easiest approach to visualizing this? I ...
0
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1answer
43 views

Create vector for each vertex in a network [closed]

I have a network with x vertices and I would like to create a vector with random numbers for each vertex in this network. I would like to generate this list and represent it in a table. Further, it ...
2
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1answer
216 views

Plotting 3D Vector Field in one plane

I want to plot a vector field F={Fx, Fy, Fz}. However, I only want to plot it in one plane (say, z=0). When I use ...
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2answers
160 views

Orthogonal vector in two dimensions

Maybe this is really basic, but I couldn't figure it out. I would like to find the "hat vector" of a vector I defined: it's a vector orthogonal to the given one, assuming two dimensions. So for ...
2
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1answer
164 views

Solving vector equations

I made this very simple module to try and solve vector X: ...
2
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1answer
80 views

Changing the length of the vectors in vectorplot [duplicate]

I have the following code, and I've tried almost everything I can think of, even VectorColorFunction to describe magnitude. I am trying to make the length of the vectors proportional to r^{-2}, and ...
2
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0answers
84 views

Compile issues, scoping and order of evaluation

I have a few questions about compiling functions, which I think are all related to scoping and order of evaluation. I will illustrate them by a minimal example of the problem I have. I'm sorry for ...
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1answer
92 views

how to find the vector intersection in a collection of triangulated 3D points?

I'm trying to calculate the 3D point coordinates for the intersection of a vector with a plane. I have been using the following code to do this: ...
2
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2answers
115 views

How can I visualize an array of very small vectors spaced on very large grid? [duplicate]

I have data in the form points = {{1, 1, 1}, {1, 1, 2}, ...} vectors = {{2, 2, 5}, {2, 1, 7}, ...} Can somebody help to edit this data so I can ListVectorPlot a ...
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1answer
69 views

Make 2D vector norm graph

I have: List of points on 2D plane: pointsz0 = ToExpression@Import@"http://pastebin.com/raw.php?i=VQfP0HgB"; And I have some values in those numbers: ...
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3answers
934 views

How to find the magnitude of a vector?

I'm doing this exercise in Wagner's book (p.78) , and this is my attempt: ...
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2answers
133 views

How to initialize several elements per iteration with Table?

I would like to initialize this kind of vector : {0,0,1,1,0,1,0,1,1,1,1,1} with Table. I tried ...
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1answer
86 views

Problem with cross product of two columns [closed]

I am trying to perform a cross product of two "Columns" which I expect to give me a column too: Cross[{{a}, {b}, {c}}, {{x}, {y}, {z}}] but it gave me an error: Cross::nonn1: The arguments ...
6
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2answers
94 views

Complex result for Real vectors in VectorAngle

I was expecting a real angle using VectorAngle when passing real valued vectors, however I obtained a complex angle. ...
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1answer
79 views

How can I transform a matrix to a vector (vectorization)? [closed]

How can I transform a matrix to a vector in mathematica? $A=\bigg{(}\begin{matrix} a_1 &a_2\\a_3&a_4 \end{matrix}\bigg{)} \longrightarrow |a>>=(\begin{matrix} a_1 ...
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2answers
46 views

Multiply value if it includes a period

I download data from an online source, now I have a problem: the source code doesn't allow to differ between values of 10 (which actually stands for 10) and 10.000 (which is 10'000, but Mathematica ...
5
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6answers
769 views

A matrix-vector cross product

I want to do a cross product involving a vector of Pauli matrices $\vec \sigma = \left( {{\sigma _1},{\sigma _2},{\sigma _3}} \right)$; for example, $\vec \sigma \times \left( {1,2,3} \right)$. ...
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1answer
128 views

Finding the maximum of a gradient vector

Im trying to find the maximum of my gradient vector G[x,y], I've tried several options including FindMaximumValue, FindMaximum etc. but i couldn't find it. The full function is shown below, any help ...
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41 views

Get rid of external library dependency

I am trying to generate C code for some functions, which I do not post in full because they are a few hundred lines long. The functions do nothing too fancy: a bunch of dot products, powers and roots. ...
3
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2answers
129 views

Is it possible to specify the direction of rotation in VectorAngle function?

If I use the function VectorAngle[{1,0},{1,-1}], is it possible to obtain the angle generated by rotating around the axis counter clock wise? In other words, I would move from the first vector to the ...
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2answers
145 views

Selecting parts of a matrix via indices given by a vector

I have a column vector of the form $\{1, 1, 2, 3, 2, 3\}^t$ and an associated matrix that has the same number of rows as the column vector, $6$, and a number of columns that is equal to the maximum of ...
2
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1answer
694 views

How to Normalise / Normalize eigenvectors? [closed]

I have a matrix and am trying to find the normalised eigenvectors of it. I am using the Eigensystem command and am getting a result. There is a normalize command, but as far as I can see this ...
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1answer
138 views

Placing many arrowheads on curves

I can't find anything anywhere on the web to help me with this. My plot: ...
6
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2answers
521 views

Animated Vector plot

I'm trying to make an animation of a time-varying 2D vector field. However, I'm got a difficulty in that Mathematica normalises the length of the vectors with each call to ...
3
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3answers
130 views

how can I make a control for my vector equation in my simulation?

I'm trying to build a control selector or menu for equations to put into my curvature simulations. However all the code I've tried hasn't worked.Does anyone know how I could make a control selector or ...
0
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1answer
59 views

Visualizing vectors [closed]

How to visualize a set of vectors with 3 coordinates $(x,y,z)$, e.g.,$(1,1,1), (1,-1,-1),(-1,1,-1),(-1,-1,1)$? In fact there are many of them. I try the function "Graphic3D" with the following code ...
1
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0answers
72 views

Plotting Phase Space [duplicate]

I have these two Equ' $$x'[t]=Sin[y]$$ $$y'[t]=Cos[x]$$ and im trying to plot the phase space(plane) for this system... ive tryed Equationtrekker but cant seem to find the way to use it this way... ...
1
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1answer
65 views

Simplification of linear algebra [duplicate]

I have a few vectors defined as V1 = Array[v1,3] V2 = Array[v2,3] V3 = Array[v3,3] And I am trying to solve a very simple equation along the lines of ...
1
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1answer
123 views

Show that three given vectors lie on a line, a plane, or span 3-space

Given three vectors, {2, 0, 0}, {0, 2, 2}, {2, 2, 3}, how could I see if they are all on the ...
0
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1answer
115 views

Select positive value from a vector

I am wondering how to pick out the positive Omega value from soln, and make these positive values into a row vector. I know how ...
0
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1answer
73 views

Curvature Manipulation: Vector Evaluation Error [closed]

I am building a mathematical simulation of curvature that will show the Osculation circle at each point on a curve. However my code keeps coming up with errors and ...