linalg 0.4.0

A Simple Linear Algebra Package enabling easy Matrix calculations.

example/example.dart

import 'package:linalg/linalg.dart';

void readMeExample() {
  final Matrix a = Matrix([
    [1, 2],
    [3, 4]
  ]);
  final Vector b = Vector.column([2, 3]);
  final Matrix e = Matrix([
    [8],
    [18]
  ]);
  Matrix result = a * b;
  print(result);
  print(result == e);
}

/// Example code for using the Matrix class.
void main() {

  readMeExample();

  // *****************************
  // Lets solve a linear equation.
  // *****************************
  //
  // A * B = E
  //
  // We have B and E, we have to find A.
  //
  // A * B * B' = E * B'
  //
  // Were B' = inverse of B.
  //
  // A * I = E * B'
  //
  // Where I = identity matrix
  //
  // A = E * B'
  final Matrix B = Matrix([
    [2.0, 0.0],
    [1.0, 2.0]
  ]);
  final Matrix E = Matrix([
    [4.0, 4.0],
    [10.0, 8.0]
  ]);

  Matrix Bi = B.inverse();
  Matrix A_calc = E * Bi;

  final Matrix A = Matrix([
    [1.0, 2.0],
    [3.0, 4.0]
  ]);
  print(
      "The calculated A = $A_calc, the expected A is $A, they are ${A_calc == A ? '' : 'not'} the same.");
  // Expected: The calculated A = [[1.0, 2.0], [3.0, 4.0]], the expected A is [[1.0, 2.0], [3.0, 4.0]], they are  the same.

  // *****************************
  // Lets do some more matrix math
  // *****************************
  //
  // Next let multiply Matrix A by 3.
  Matrix Am = A * 3.0;
  print(Am);
  // Expecting: [[3.0, 6.0], [9.0, 12.0]]

  // Now add matrix B to A
  Matrix AmPlusB = Am + B;
  print(AmPlusB);
  // Expecting: [[5.0, 6.0], [10.0, 14.0]]

  // What is the determinant of the A matrix?
  print("The determinant of A = ${A.det()}");
  // Expecting The determinant of A = -2.0
}