Questions on the manipulation of matrices in Mathematica.

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1
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2answers
52 views

How to compare and remove x-coordinates (and the associated y-coordinates) that are less than previous x-coordinates?

I am using Mathematica version 9.0 and am trying to compare and remove x-coordinates, and the associated y-coordinate, that are less than previous x-coordinates. Below is an example using sample data. ...
2
votes
2answers
70 views

Reading from a file: complex number with small imaginary part

I'm trying to read a matrix from the next file: 1+1e-18i 24 42 23.43e-23i using u=Import["file.dat","Table"]; and then find, ...
1
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0answers
45 views

Simplest use of transpose given a vector and a matrix [on hold]

Suppose that I have: x = {1, 1}/Norm[{1, 1}]; A = {{1, 2}, {2, 1}}; What is the simplest way of calculating $x^T A\ x$? And are there symbols on any of the ...
0
votes
0answers
25 views

Issue with Differentiation over a tensor

I am new user in Mathematica. I am working with liquid crystal theory, and one of the notation there is the tensor: $ \Pi_{ij} = \frac {\partial {F_{el}}} { \partial ( \partial {n_i} / \partial { ...
3
votes
1answer
43 views

Saving Dot-ed eigenvectors in a special comparison

We have produced a 4*4 matrix in any iteration containing nx from 0 to 2 by steps of 0.5. and in any iteration we have saved sorted orthogonalized-eigenvectors based on their eigenvalues with this ...
15
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4answers
664 views

Can (compiled) matrix permanent evaluation be further sped-up?

Update III  Mathematica 10.2.0 now ships with a predefined System`Permanent function, which the PermanentCode package ...
1
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0answers
102 views

MatrixExp of a complex matrix of size about 10000 by 10000 [on hold]

I want to apply MatrixExp of a numerical, complex matrix of size about 10000 by 10000, and I also need high precision as I need to multiply several such matrices. ...
8
votes
2answers
137 views

Difficulty using LUDecomposition

I'm having trouble using LUDecomposition with pivoting. I read the Mathematica help on this particular command, but I'm still lost. Take a matrix like: ...
0
votes
0answers
43 views

Solving matrix optimization

I have the following problem. Let $X_1, X_2, \cdots, X_k$ are $n \times n$ Hermitian matrices (need not be positive) given. Let a $n \times n$ positive matrix $A$ is given such that $Tr(A.X_j)<0$ ...
7
votes
2answers
168 views

Why is mathematica eating a row from QRDecompostion

I'm attempting to calculate the QRDecomposition of the matrix: a= {{1,3},{0,5},{2,-8}} QRDecomposition [a] The answer mathematica gives me is: - Q which is a ...
-3
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0answers
59 views

I want a mix matrix [on hold]

I have a matrix with dimensions m x n and elements f[p, q] and another matrix with dimensions i x j and elements g[r, s]. How ...
1
vote
1answer
48 views

calculate relationship between cause and effect (rows/columns/delta etc.) on tableform

I tried to enter this Excel (on the right of the picture) information to program. following these codes has been used: ...
5
votes
1answer
93 views

Efficient upsampling of multidimensional array

I would like to efficiently upsample a multidimensional array. It's a 5000*5 matrix where each element is a submatrix 12*12 and it is that 12*12 matrix I want upsampled (to 24*24). The upsampling ...
11
votes
2answers
433 views

How to add a vertical line to a matrix?

Today, I want to write a program to show the solving process of a the inverse of a matrix, and I use the Elementary Transformation, so I need to add a vertical ...
9
votes
3answers
1k views

Has Mathematica a function to compute the Smith Normal Form?

The Smith normal form is a matrix that can be calculated for any matrix (not necessarily square) with integer entries. See Wikipedia for a more elaborate description. Has Mathematica a function to ...
4
votes
2answers
89 views

Factor out the scalar multiplier for the dot product of 2x2 matrices

If yy and zz are 2x2 Hermitian matrices, is there a way that I can mark them (with a property?) as Hermitian so that Mathematica can assume that it can factor out and simplify scalar multipliers from ...
10
votes
2answers
3k views

How to get Matlab data imported with the same dimensions?

I have some Matlab image data with the following dimensions (output is from Matlab): >> size(im) ans = 86 86 3 45 The data imports just fine ...
5
votes
4answers
206 views

Constructing a grid from a matrix

I would like to construct a grid from a matrix. For example, one possible matrix is $M1$. $$M1= \begin{pmatrix} c2 & a1 & a1 & a1 & a1 & a1\\ a2 & b1 & c2 & a1 & ...
1
vote
1answer
45 views

Pure “Select” function over matrix

I have several lists of tuples in the following shape: l1 = {{1, 134}, {2, 314}, {3, 164}} I do want to select, from each list, list elements fulfilling a ...
5
votes
1answer
588 views

Matrix Rational Canonical Form

Is there a way to calculate the Rational Canonical Form of an $n\times n$ integer matrix using Mathematica? I have been perusing the documentation and web, but nothing so far.
5
votes
4answers
186 views

Split matrix by all-zero columns

Below is my input: mat = {{0, 0, 0, 0, 0, 1}, {1, 0, 0, 1, 0, 1}, {0, 1, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 1}, {1, 1, 0, 1, 0, 0}, {0, 0, 0, 1, 0, 1}}; ...
1
vote
1answer
47 views

Sort and Save Matrices Eigenvectors to a Larger Matrix

We are going to sort and save all orthoginalized-eigenvectors of 4*4 random matrices (produced in any iteration) to a larger matrix such as storagematrix. Since, produced random matrices are 4*4, ...
6
votes
2answers
187 views

Can't find the eigenvectors of a simple 2x2 matrix

Bug introduced in 8.0 or earlier and persisting through 10.2.0 Why can't Mathematica find the eigenvectors of this matrix? ...
2
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0answers
42 views

Parallel evaluation of symbolic matrix eigenvalues

I'm trying to find eigenvalues of symbolic hermitian 40x40 block matrix. It is made from 20 2x2 matrices like this: ArrayFlatten[Table[M[m,n],{m,1,20},{n,1,20}]] ...
0
votes
1answer
49 views

Element assignment in matrix function

I have to define a function of two variables that yields a high dimensional matrix, with each entry containing a scalar function, that uses its coordinates in the matrix as input. like this: ...
2
votes
1answer
122 views

Mathematica error code 0x00000171

I'm getting above error code with a Trap 132 indication when attempting an ArrayPlot of a complex 130000 x 2048 matrix. Using Mathematica 9.0.1 with Mac OS 10.10.3 ...
10
votes
2answers
3k views

Badly conditioned matrix (General::luc)

With some matrices, I am receiving the following message: ...
7
votes
3answers
718 views

How to estimate the matrix condition number in the 2-Norm?

The Mathematica documentation says it is possible to estimate the matrix condition number in norms 1, 2, and ∞. But the 2-norm raises a message. This is an extract from reference documentation ...
0
votes
0answers
46 views

Generating this type of Matrix

How I can generate a matrix of order $N$ if $N$ is odd then $$\left[ \begin{array}{cccccc} \frac{1}{0! 0! 2^0} & 0 & \frac{-1}{0! 1! 2^1} & \cdots & ...
1
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0answers
43 views

How do I diagonalize a matrix? [closed]

How do I diagonalize the following matrix: ...
1
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0answers
44 views

How to remove parts of an expression

I have an expression where terms Transpose[R].R appear. R is a matrix with the property Transpose[R].R=IdentityMatrix[3]. How ...
5
votes
1answer
98 views

Distribute transpose on matrix multiplication

I need to do the following: Transpose[A.(B+C)]=Transpose[B].Transpose[A]+Transpose[C].Transpose[A] How should I do this in mathematica? So far mathematica does ...
0
votes
3answers
77 views

Do not expand matrices in Mathematica calculation

Here is an example of a problem I'm having. Consider that I have defined: omega={{p[t]},{q[t]},{r[t]}} x={{a},{b},{c}} R={{1,2,3},{4,5,6},{7,8,d}} What I would ...
32
votes
2answers
828 views

eigenvector bug?

Bug introduced in 7.0.1 or earlier and fixed in 10.0.0 I have a fairly simple $3\times3$ complex matrix, $$ M=\left( \begin{array}{ccc} \frac{7}{2}-\frac{i}{2} & -1+i & \frac{1}{2}+\frac{5 ...
1
vote
1answer
61 views

Calculating a multiplication of large number of matrices takes a long time [duplicate]

I have a multiplication of matrices, say M1.G1.M2.G2.....Mn.Gn, here n may reach 100. M and G are 4 4 matrices and their elements are function of s. Mathematica takes so long to perform this ...
4
votes
0answers
63 views

How can I force the use of sparse diagonalization methods?

When I evaluate the Eigenvalues function on a very large (e.g. 2^16 x 2^16) sparse matrix, Mathematica says something like: Because finding 65536 out of the ...
10
votes
1answer
309 views

Is it possible to implement symbolic sub matrices?

The accepted answer in the question Symbolic matrices in Mathematica with unknown dimensions provides a functionality to create symbolic matrices which behave pretty much as the name suggests. ...
0
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2answers
83 views

Matrixform ndsolve for mobile robot dynamic equations

Error is: NDSolve::ndsdtc: The time constraint of 1.` seconds was exceeded trying to solve for derivatives, so the system will be treated as a system of differential-algebraic equations. You ...
0
votes
0answers
32 views
1
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1answer
62 views

Transposition of state space form of a transfer function

How can I transpose the output of state space model in Mathematica? trying the following code would transpose the top right symbol s instead of the matrices. ...
0
votes
0answers
11 views

Find new coordinates after rotating a shape centrally [migrated]

i want to find new points of shape in Cartesian coordinate system after applying an angle on shape. What is formula to find these points
0
votes
1answer
121 views

Finite Field matrix rank calculation

How does one define a matrix over $\mathrm{GF}(p^r)$ in Mathematica in order to compute rank? I am working with $\mathrm{GF}(2)$?
9
votes
2answers
969 views

How to transform a 3D image by an affine transformation matrix

I have a question concerning Image Processing: I have a stack of images, which I can compose to a 3D image using Image3D. Additionally I have a 4x4 affine transformation matrix. I would like to ...
1
vote
1answer
78 views

multiplication of 4*4 matrices whose elements are function of x and y [closed]

I have a matrix 4*4 M whose elements are a function of x and y. I would like to multiply this matrix for different values of x and y, say M[1,1].M[2,2]......M[n,n]. How I can do it?
25
votes
1answer
272 views

Does Mathematica store hidden information for matrix objects?

Bug introduced in 10.0 and fixed in 10.2.0 I found a case where calling one built-in function (HermitianMatrixQ) for a given matrix changes the behavior of ...
2
votes
1answer
43 views

Problem with NDSolve and Sign

If c1 cnd c2 are zero, the code responds very well; but if one of c1 or ...
6
votes
3answers
177 views

On a strange pattern of triangular numbers in Ulam's spiral

In this MSE post, user GeMir noticed that, where the green dots are the triangular numbers, $$T_n = \frac{n(n+1)}{2} = 1,3,6,10,15,21,28,36,45,55,66,78,91,105,120,136,\dots$$ in the Ulam spiral ...
2
votes
1answer
38 views

Extract Transfer Matrix from TransferFunctionModel

I have a MIMO transfer function model, and I'd like to know how to perform arithmetic on this model. For instance, to see the difference between two systems' outputs for arbitrary inputs, I'd like to ...
5
votes
3answers
241 views

Huge matrices crashes in Mathematica

I have a matrix of data ~(70,000x70,000). I am searching connection between these data points. I use euclidean distance for that purpose. If it is less than my threshold (that means they have ...
9
votes
4answers
271 views

Finding the position of similar elements in a matrix

I want to find the position of the elements which are equal in a matrix. For example in the case of the following matrix: $m =\left( \begin{array}{cc} a & x \\ x & a \\ \end{array} \right)$ ...