node-gsl-matrix
v0.1.0
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A node library for matrix manipulation leveraging GSL
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node-gsl-matrix
This package exposes matrix functionality provided by GSL. For many applications such as scientific computing, fast matrix operations are critical. By using GSL, we can take advantage of all the heavy lifting done in the library to provide fast matrix operations.
While GSL also provides a variety of other classes (such as vectors, views, etc.) the goal of this library is simplicity. The only type of object exposed is a matrix. Vectors should be represented as matricies with one of the dimensions set to 1.
Installation
First you'll need to get an installation of GSL. If you're on OS X, you can just use brew.
brew install gsl
Then you should be able to install this package via npm.
npm install --save node-gsl-matrix
Usage
The constructor takes as arguments the number of rows and columns. You should always instantiate objects using this method.
var Matrix = require('node-gsl-matrix').Matrix;
var myMatrix = new Matrix(4, 3); // A 4x3 matrix
Note that the values in the matrix have no guaranteed initialization. The Matrix
object has the methods below (all examples presume that myMatrix
is a 3x3 identity matrix and otherMatrix
is a 1x3 matrix equal to [10, 11]
):
addScaledRow
Adds a scaled row from another matrix to a row of the target matrix.
// Add first (and only) row of otherMatrix scaled by 2.0 to second row of myMatrix.
myMatrix.addScaledRow(1, otherMatrix, 0, 2.0);
myMatrix; // [[1, 0], [20, 23]]
// Last argument is optional and assumed to be 1 if not provided.
myMatrix.addScaledrow(1, otherMatrix, 0);
myMatrix; // [[1, 0], [10, 12]]
// Third argument is optional and assumed to be 0 if not provided.
myMatrix.addScaledrow(1, otherMatrix);
myMatrix; // [[1, 0], [10, 12]]
get
Return the value in a particular entry
myMatrix.get(0, 0); // 1
innerProduct
Return the inner product of a row in this matrix with a row in another matrix
// Compute the inner product of the second row of myMatrix
// with the first (and only) row of otherMatrix
myMatrix.innerProduct(1, otherMatrix, 0); // 11
// Last argument is optional, first row is assumed.
myMatrix.innerProduct(1, otherMatrix); // 11
scale
Multiplies all values in the matrix by a constant value.
myMatrix.scale(0.1);
myMatrix; // [[0.1, 0] [0, 0.1]]
set
Set a particular entry to a value
myMatrix.set(0, 1, 8);
myMatrix; // [[1, 8], [0, 1]]
setAll
Sets all values in the matrix to a value
myMatrix.setAll(7);
myMatrix; // [[7, 7], [7, 7]]
setRow
Sets all values in a particular row to a value
myMatrix.setRow(0, 6);
myMatrix; // [[6, 6], [0, 1]]
License
node-gsl-matrix is available under the MIT license.