Mathematical vectors, operations on vectors and vectorized programming.

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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 ...
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0answers
24 views

convert a raster colorful image to a vector one [on hold]

how we can convert a raster colorful image to a vector one with java code. I should write a java code that do this or a free library.
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1answer
106 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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0answers
31 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. ...
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3answers
401 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
110 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
105 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
54 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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2answers
56 views
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1answer
104 views

Placing many arrowheads on curves

I can't find anything anywhere on the web to help me with this. My plot: ...
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1answer
55 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 ...
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0answers
40 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... ...
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3answers
124 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 ...
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1answer
46 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 ...
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1answer
78 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
votes
1answer
57 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 ...
0
votes
1answer
50 views

Plotting multiple vector fields with different domains in a single graph

I have attached a scheme of the problem. Essentially what I need is to plot 2 different vector fields in a single graph with different domains. The underlying physical problem is to model electric ...
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0answers
48 views

vector/list containing matrices as elements dot product [closed]

mA = {{a11, a12}, {a21, a22}}; mB = {{b11, b12}, {b21, b22}}; mC = {{c11, c12}, {c21, c22}}; mD = {{d11, d12}, {d21, d22}}; v={{mA},{mB}}; w={{mC},{mD}}; What I ...
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1answer
83 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 ...
2
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1answer
72 views

Taylor expansion of function of vectors—simplifying the output

I've got a real-valued function of several vectors $f(u,v,w)$ formed by taking scalar products of linear combinations of the vectors, I want to Taylor expand around small $v$ by writing $$f(u,\delta ...
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0answers
40 views

ListVectorPlot3D invalid dataset [duplicate]

I have generated a dataset which seems to fine according to the help page of Mathematica for a ListVectorPlot3D but, it says it is not a valid set. I have given the data set below, could someone ...
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0answers
30 views

X-axis obscuring a vector that lies along it [duplicate]

I am having the following problem. I am playing with Manipulate and I would like to draw a vector overlapping an axis (x-component of a vector), and I would like ...
1
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1answer
60 views

Partitioning a list and gathering statistics on the distribution of values across partitions

I have a one-dimensional array of 200 elements consisting of the numbers 0, 1, 2. This array needs to be divided into 10 groups (20 items each). Then, for each group, I want to count how many of the ...
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1answer
84 views

Vector-calculus [duplicate]

I have a table of 200 elements, elements are '0', '1', '2'. I have participate them into groups for 20 elements each one. Then I have calculate how many '0', '1', '2' are in each part. And then in ...
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1answer
74 views

Operator operation

There are two basic operators r={x,y,z} and p=-I*h*{D[#,x] , D[#,y], D[#,z]} &. The angular momentum operator is defined as ...
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0answers
30 views

Is it possible to obtain vector differentiation results in terms of vectors rather than components? [duplicate]

When doing certain operations on vectors in Mathematica it is quite desirable to convert the results back into coordinate-free notation. Unfortunately, after going through the Documentation Center and ...
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2answers
64 views

Computing symbolic norm of a vector

Consider the code: n1 := Cos[α] Sin[β] n2 := Sin[α] Sin[β] n3 := Cos[β] n := {n1, n2, n3} Norm[n] Why the result is ...
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0answers
82 views

Visualizing 3D vector field on surface of sphere [duplicate]

I want to vizualize (quite complicated) 3D vector field which has both real and imaginary part and is expressed in spherical coordinates. I was thinking about expressing the field for certain r and ...
0
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1answer
68 views

Factor a Vector

Does there exist a function in Mathematica that simply takes out a common factor from a vector/list of expressions? This seems like such a simple operation that I am surprised that I could not find it ...
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2answers
236 views

Using the epsilon tensor in Mathematica

I'm having a great deal of trouble getting started on a weekly homework assignment in Mathematica. The assignment requires we use the epsilon tensor which is apparently built into Mathematica as ...
0
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0answers
36 views

Using Manipulate, how do you display the points on the curve and the tangent vector? [duplicate]

I'm new to Mathematica and my assignment is very vague... I'm hoping someone can explain to me a bit more of that this quesion means: Given the curve C, display the point on the curve and the ...
0
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1answer
51 views

Function output of two lists are only diagonal elements

I'm having a little crysis over here. What I basically want to do is some sort of 3D-Plot, but I'm only interested in the resulting values. I have two vectors x and p: ...
0
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1answer
158 views

Symbolic matrix simplification and solving

I am trying to expand or solve an equation that contains matrices for a certain matrix, but it is not working: ...
5
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0answers
175 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
225 views

How to make a point's position time-dependent given a formula for the next step?

I've made a program that is just some points on a plane. Red points are cops and green points are robbers. Each point has a vector indicating where it is going to be in the next step of $t$. Right now ...
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0answers
94 views

Gradient from Vectors type

I'm working with Vectors type in Mathematica 9. For this purpose I use the following command: ...
4
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2answers
1k views

How to combine two vectors into a matrix by columns?

I know it may sounds idiot, but I've been looking through the document, and couldn't find a way to combine two vectors say {a, b} and ...
0
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1answer
99 views

Rotating a set of 3D points against an arbitrary axis

I want to rotate a list of 3D points around unit vector (1,0,1) by the angle of Pi. How can I accomplish it?
2
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1answer
158 views

Plot Piecewise-Smooth Vector Field.

I want to plot a piecewise-smooth vector field. For instance: $F_1(x,y) = (x^2 + y^2, y^2)$, $F_2 (x,y) = (2xy,2xy-x^2)$ and $H(x,y) = x-y$ $F(x,y) = \begin{cases} F_1(x,y) \text{ if } H(x,y) ...
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1answer
100 views

replace is not happening for specific vector valued expression

Given x[t_] := {Subscript[x, 1][t], Subscript[x, 2][t]} following replace works fine x[t] /. x[t] -> 0 0 but following ...
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2answers
64 views

How do I avoid vector variables being treated as scalars in the course of replacements?

I often work with a mixture of symbolic and concrete values as I develop teaching materials. I introduce variables symbolically and then need to instantiate them to specific values while continuing ...
4
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1answer
137 views

Orthogonalizing without normalizing

Is there a way to make Orthogonalize do the normal Gram-Schmidt procedure without normalizing the result? As far as I've understood this was possible with ...
2
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1answer
206 views

Plotting a Gravity-Field [duplicate]

I try to plot a 2D gravity field or something similar in the form like $r/|r|^3$ with the standart builtin VectorPlot function: ...
2
votes
2answers
414 views

Circular Orbit Velocity in Vector Components

I'm trying to find out how to calculate the initial velocity needed to keep a spacecraft in a circular orbit around the Earth given its initial position and an initial angle theta in a Cartesian ...
4
votes
2answers
283 views

Plotting: Is anyone familiar with gradientfieldplot command?

I am trying to plot this graph showing the electric field lines and lines of equipotential based off the electrode configuration(in black) of two parallel lines. This is what I've been using for other ...
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2answers
175 views

Plotting problem

I was wondering why I keep receiving the error message "Derivative should be a triple of numbers, or scaled form" from the following code ...
0
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1answer
215 views

Simplify vector expression - is there something like “Factor” for vectors, dot products etc.?

I am looking for a way to simplify dot products etc. Here is a minimal example: Lets say I have two vectors a and b: Array[a,2] Array[b,2] Now I evaluate their ...
0
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2answers
427 views

How to input a 3-vector in spherical coordinates?

I would like to input a 3-vectors in spherical coordinates $(r, \theta, \phi)$ and be able to operate on such vectors (dot and cross product) with the results being given in the same spherical ...
1
vote
3answers
452 views

Adding a Sphere onto an existing 3D plot

I have a 3D plot. I need to add a small sphere marking the starting point, r[t] == 0. I'm pretty new at Mathematica and would greatly appreciate some help. ...
4
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2answers
149 views

Assumptions for RotationMatrix

I'm making C++ program, and in my program I need a rotation matrix around any vector. I wanted to extract RotationMatrix[fi,{x,y,z}] output and put it in my ...