New answers tagged linear-algebra
2
votes
Least norm solution to a set of linear equations
If I'm not mistaken, this is what you're looking for:
Inputs for a problem of the form mat.x == y:
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- 18.3k
5
votes
Accepted
Least norm solution to a set of linear equations
It is a standard fact that x = PseudoInverse[M].b does what I think you want, namely: Return an x that minimizes ...
- 773
4
votes
Finding eigenvectors of a symbolic matrix
Here is one, not particularly sophisticated, approach using Normalize. You could use
evs = Map[Normalize,Eigenvectors[{{a,b},{b,-a}}]];
to get normalized ...
- 773
7
votes
Accepted
Matrix Integro-differential equation
The problem can easily be solved after reformulation to a system of ODEs. Let us start with
$$
\frac{d\rho}{dt}=-i[H_{0}(t),\rho(t)]-A^{2}\Big[H_{1},\int_{t1}^{t}e^{-B(t-s)}\Big(e^{-i\int_{s}^{t}H_{0}(...
- 16.1k
3
votes
How to find the index of a square matrix in Mathematica quickly?
In version 13.0.1, there is a undocumentation function LinearAlgebra`MatrixIndex. But I'm not sure when this is introduced
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- 23.7k
2
votes
Solution to a linear equation with minimum rank
We can use Nonnegative Least Squares Algorithm (NNLS) discussed here to solve matrix equation X.M=A with constraints ...
- 34.1k
2
votes
Approximate strictly positive solution to a linear set of equations?
THIS IS AN EXTENDED COMMENT RATHER THAN AN ANSWER.
It is inefficient to use Table to generate random numbers.
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- 121k
11
votes
Nonnegative Least Squares Algorithm (NNLS)
We can compare 6 algorithms based on FindMinimum,NMinimize, ConvexOptimization, ...
- 34.1k
0
votes
How to solve this equation with matrix rank condition
The build-in function MatrixRank cannot work in symbolic matrix. So I make a symbolic version MatrixRankSym here, then:
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- 23.7k
3
votes
Solution to a linear equation with minimum rank
Your transposed equation looks like Transpose[M].Transpose[X]==Transpose[A]
LeastSquares finds the minimal solution
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- 37k
8
votes
Accepted
How to obtain independent variables from a set of linear constraints
First one can set up and solve the system.
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- 55.5k
2
votes
How can I generate a tridiagonal block matrix?
The matrix you have is block tridiagonal and block Toeplitz.
I'll give two methods: one that uses nothing but documented functionality, and one that uses undocumented functionality.
First up is an ...
4
votes
How can I generate a tridiagonal block matrix?
It must be many ways to do this,here we provide one way.
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- 33.1k
11
votes
Is it possible to use the DGEEV and DSYEV LAPACK subroutines in Mathematica?
You can use LibraryLink to call LAPACK directly. It involves however quite a lot of boilerplate code. Here is an example:
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- 95.6k
0
votes
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