Matrix3

new Matrix3(column0Row0, column1Row0, column2Row0, column0Row1, column1Row1, column2Row1, column0Row2, column1Row2, column2Row2)

A 3x3 matrix, indexable as a column-major order array. Constructor parameters are in row-major order for code readability.
Name Type Default Description
column0Row0 Number 0.0 optional The value for column 0, row 0.
column1Row0 Number 0.0 optional The value for column 1, row 0.
column2Row0 Number 0.0 optional The value for column 2, row 0.
column0Row1 Number 0.0 optional The value for column 0, row 1.
column1Row1 Number 0.0 optional The value for column 1, row 1.
column2Row1 Number 0.0 optional The value for column 2, row 1.
column0Row2 Number 0.0 optional The value for column 0, row 2.
column1Row2 Number 0.0 optional The value for column 1, row 2.
column2Row2 Number 0.0 optional The value for column 2, row 2.
See:

Members

staticMatrix3.COLUMN0ROW0

The index into Matrix3 for column 0, row 0.

staticMatrix3.COLUMN0ROW1

The index into Matrix3 for column 0, row 1.

staticMatrix3.COLUMN0ROW2

The index into Matrix3 for column 0, row 2.

staticMatrix3.COLUMN1ROW0

The index into Matrix3 for column 1, row 0.

staticMatrix3.COLUMN1ROW1

The index into Matrix3 for column 1, row 1.

staticMatrix3.COLUMN1ROW2

The index into Matrix3 for column 1, row 2.

staticMatrix3.COLUMN2ROW0

The index into Matrix3 for column 2, row 0.

staticMatrix3.COLUMN2ROW1

The index into Matrix3 for column 2, row 1.

staticMatrix3.COLUMN2ROW2

The index into Matrix3 for column 2, row 2.

staticMatrix3.IDENTITY

An immutable Matrix3 instance initialized to the identity matrix.

Methods

clone(result)Matrix3

Duplicates the provided Matrix3 instance.
Name Type Description
result Matrix3 optional The object onto which to store the result.
Returns:
The modified result parameter or a new Matrix3 instance if one was not provided.

equals(right)Boolean

Compares this matrix to the provided matrix componentwise and returns true if they are equal, false otherwise.
Name Type Description
right Matrix3 optional The right hand side matrix.
Returns:
true if they are equal, false otherwise.

equalsEpsilon(right, epsilon)Boolean

Compares this matrix to the provided matrix componentwise and returns true if they are within the provided epsilon, false otherwise.
Name Type Description
right Matrix3 optional The right hand side matrix.
epsilon Number The epsilon to use for equality testing.
Returns:
true if they are within the provided epsilon, false otherwise.

toString()String

Creates a string representing this Matrix with each row being on a separate line and in the format '(column0, column1, column2)'.
Returns:
A string representing the provided Matrix with each row being on a separate line and in the format '(column0, column1, column2)'.

staticMatrix3.abs(matrix, result)Matrix3

Computes a matrix, which contains the absolute (unsigned) values of the provided matrix's elements.
Name Type Description
matrix Matrix3 The matrix with signed elements.
result Matrix3 optional The object onto which to store the result.
Returns:
The modified result parameter or a new Matrix3 instance if one was not provided.

staticMatrix3.clone(matrix, result)Matrix3

Duplicates a Matrix3 instance.
Name Type Description
matrix Matrix3 The matrix to duplicate.
result Matrix3 optional The object onto which to store the result.
Returns:
The modified result parameter or a new Matrix3 instance if one was not provided. (Returns undefined if matrix is undefined)

staticMatrix3.determinant(matrix)Number

Computes the determinant of the provided matrix.
Name Type Description
matrix Matrix3 The matrix to use.
Returns:
The value of the determinant of the matrix.

staticMatrix3.equals(left, right)Boolean

Compares the provided matrices componentwise and returns true if they are equal, false otherwise.
Name Type Description
left Matrix3 optional The first matrix.
right Matrix3 optional The second matrix.
Returns:
true if left and right are equal, false otherwise.

staticMatrix3.equalsEpsilon(left, right, epsilon)Boolean

Compares the provided matrices componentwise and returns true if they are within the provided epsilon, false otherwise.
Name Type Description
left Matrix3 optional The first matrix.
right Matrix3 optional The second matrix.
epsilon Number The epsilon to use for equality testing.
Returns:
true if left and right are within the provided epsilon, false otherwise.

staticMatrix3.fromArray(array, startingIndex, result)Matrix3

Creates a Matrix3 from 9 consecutive elements in an array.
Name Type Default Description
array Number[] The array whose 9 consecutive elements correspond to the positions of the matrix. Assumes column-major order.
startingIndex Number 0 optional The offset into the array of the first element, which corresponds to first column first row position in the matrix.
result Matrix3 optional The object onto which to store the result.
Returns:
The modified result parameter or a new Matrix3 instance if one was not provided.
Example:
// Create the Matrix3:
// [1.0, 2.0, 3.0]
// [1.0, 2.0, 3.0]
// [1.0, 2.0, 3.0]

var v = [1.0, 1.0, 1.0, 2.0, 2.0, 2.0, 3.0, 3.0, 3.0];
var m = Cesium.Matrix3.fromArray(v);

// Create same Matrix3 with using an offset into an array
var v2 = [0.0, 0.0, 1.0, 1.0, 1.0, 2.0, 2.0, 2.0, 3.0, 3.0, 3.0];
var m2 = Cesium.Matrix3.fromArray(v2, 2);

staticMatrix3.fromColumnMajorArray(values, result)

Creates a Matrix3 instance from a column-major order array.
Name Type Description
values Number[] The column-major order array.
result Matrix3 optional The object in which the result will be stored, if undefined a new instance will be created.
Returns:
The modified result parameter, or a new Matrix3 instance if one was not provided.

staticMatrix3.fromQuaternion(quaternion)Matrix3

Computes a 3x3 rotation matrix from the provided quaternion.
Name Type Description
quaternion Quaternion the quaternion to use.
Returns:
The 3x3 rotation matrix from this quaternion.

staticMatrix3.fromRotationX(angle, result)

Creates a rotation matrix around the x-axis.
Name Type Description
angle Number The angle, in radians, of the rotation. Positive angles are counterclockwise.
result Matrix3 optional The object in which the result will be stored, if undefined a new instance will be created.
Returns:
The modified result parameter, or a new Matrix3 instance if one was not provided.
Example:
// Rotate a point 45 degrees counterclockwise around the x-axis.
var p = new Cesium.Cartesian3(5, 6, 7);
var m = Cesium.Matrix3.fromRotationX(Cesium.Math.toRadians(45.0));
var rotated = Cesium.Matrix3.multiplyByVector(m, p);

staticMatrix3.fromRotationY(angle, result)

Creates a rotation matrix around the y-axis.
Name Type Description
angle Number The angle, in radians, of the rotation. Positive angles are counterclockwise.
result Matrix3 optional The object in which the result will be stored, if undefined a new instance will be created.
Returns:
The modified result parameter, or a new Matrix3 instance if one was not provided.
Example:
// Rotate a point 45 degrees counterclockwise around the y-axis.
var p = new Cesium.Cartesian3(5, 6, 7);
var m = Cesium.Matrix3.fromRotationY(Cesium.Math.toRadians(45.0));
var rotated = Cesium.Matrix3.multiplyByVector(m, p);

staticMatrix3.fromRotationZ(angle, result)

Creates a rotation matrix around the z-axis.
Name Type Description
angle Number The angle, in radians, of the rotation. Positive angles are counterclockwise.
result Matrix3 optional The object in which the result will be stored, if undefined a new instance will be created.
Returns:
The modified result parameter, or a new Matrix3 instance if one was not provided.
Example:
// Rotate a point 45 degrees counterclockwise around the z-axis.
var p = new Cesium.Cartesian3(5, 6, 7);
var m = Cesium.Matrix3.fromRotationZ(Cesium.Math.toRadians(45.0));
var rotated = Cesium.Matrix3.multiplyByVector(m, p);

staticMatrix3.fromRowMajorArray(values, result)

Creates a Matrix3 instance from a row-major order array. The resulting matrix will be in column-major order.
Name Type Description
values Number[] The row-major order array.
result Matrix3 optional The object in which the result will be stored, if undefined a new instance will be created.
Returns:
The modified result parameter, or a new Matrix3 instance if one was not provided.

staticMatrix3.fromScale(scale, result)

Computes a Matrix3 instance representing a non-uniform scale.
Name Type Description
scale Cartesian3 The x, y, and z scale factors.
result Matrix3 optional The object in which the result will be stored, if undefined a new instance will be created.
Returns:
The modified result parameter, or a new Matrix3 instance if one was not provided.
Example:
// Creates
//   [7.0, 0.0, 0.0]
//   [0.0, 8.0, 0.0]
//   [0.0, 0.0, 9.0]
var m = Cesium.Matrix3.fromScale(new Cesium.Cartesian3(7.0, 8.0, 9.0));

staticMatrix3.fromUniformScale(scale, result)

Computes a Matrix3 instance representing a uniform scale.
Name Type Description
scale Number The uniform scale factor.
result Matrix3 optional The object in which the result will be stored, if undefined a new instance will be created.
Returns:
The modified result parameter, or a new Matrix3 instance if one was not provided.
Example:
// Creates
//   [2.0, 0.0, 0.0]
//   [0.0, 2.0, 0.0]
//   [0.0, 0.0, 2.0]
var m = Cesium.Matrix3.fromUniformScale(2.0);

staticMatrix3.getColumn(matrix, index, result)Cartesian3

Retrieves a copy of the matrix column at the provided index as a Cartesian3 instance.
Name Type Description
matrix Matrix3 The matrix to use.
index Number The zero-based index of the column to retrieve.
result Cartesian3 optional The object onto which to store the result.
Returns:
The modified result parameter or a new Cartesian3 instance if one was not provided.
Throws:
See:

staticMatrix3.getEigenDecomposition(matrix, result)Object

Computes the eigenvectors and eigenvalues of a symmetric matrix.

Returns a diagonal matrix and unitary matrix such that: matrix = unitary matrix * diagonal matrix * transpose(unitary matrix)

The values along the diagonal of the diagonal matrix are the eigenvalues. The columns of the unitary matrix are the corresponding eigenvectors.

Name Type Description
matrix Matrix3 The matrix to decompose into diagonal and unitary matrix. Expected to be symmetric.
result Object optional An object with unitary and diagonal properties which are matrices onto which to store the result.
Returns:
An object with unitary and diagonal properties which are the unitary and diagonal matrices, respectively.
Example:
var a = //... symetric matrix
var result = {
    unitary : new Cesium.Matrix3(),
    diagonal : new Cesium.Matrix3()
};
Cesium.Matrix3.getEigenDecomposition(a, result);

var unitaryTranspose = Cesium.Matrix3.transpose(result.unitary);
var b = Cesium.Matrix3.multiply(result.unitary, result.diagonal);
Cesium.Matrix3.multiply(b, unitaryTranspose, b); // b is now equal to a

var lambda = Cesium.Matrix3.getColumn(result.diagonal, 0).x;  // first eigenvalue
var v = Cesium.Matrix3.getColumn(result.unitary, 0);          // first eigenvector
var c = Cesium.Cartesian3.multiplyByScalar(v, lambda);        // equal to Cesium.Matrix3.multiplyByVector(a, v)

staticMatrix3.getElementIndex(row, column)Number

Computes the array index of the element at the provided row and column.
Name Type Description
row Number The zero-based index of the row.
column Number The zero-based index of the column.
Returns:
The index of the element at the provided row and column.
Throws:
Example:
var myMatrix = new Cesium.Matrix3();
var column1Row0Index = Cesium.Matrix3.getElementIndex(1, 0);
var column1Row0 = myMatrix[column1Row0Index]
myMatrix[column1Row0Index] = 10.0;

staticMatrix3.getMaximumScale(matrix)Number

Computes the maximum scale assuming the matrix is an affine transformation. The maximum scale is the maximum length of the column vectors.
Name Type Description
matrix Matrix3 The matrix.
Returns:
The maximum scale.

staticMatrix3.getRow(matrix, index, result)Cartesian3

Retrieves a copy of the matrix row at the provided index as a Cartesian3 instance.
Name Type Description
matrix Matrix3 The matrix to use.
index Number The zero-based index of the row to retrieve.
result Cartesian3 optional The object onto which to store the result.
Returns:
The modified result parameter or a new Cartesian3 instance if one was not provided.
Throws:
See:

staticMatrix3.getScale(matrix, result)Cartesian3

Extracts the non-uniform scale assuming the matrix is an affine transformation.
Name Type Description
matrix Matrix3 The matrix.
result Cartesian3 optional The object onto which to store the result.
Returns:
The modified result parameter or a new Cartesian3 instance if one was not provided.

staticMatrix3.inverse(matrix, result)Matrix3

Computes the inverse of the provided matrix.
Name Type Description
matrix Matrix3 The matrix to invert.
result Matrix3 optional The object onto which to store the result.
Returns:
The modified result parameter or a new Matrix3 instance if one was not provided.
Throws:

staticMatrix3.multiply(left, right, result)Matrix3

Computes the product of two matrices.
Name Type Description
left Matrix3 The first matrix.
right Matrix3 The second matrix.
result Matrix3 optional The object onto which to store the result.
Returns:
The modified result parameter or a new Matrix3 instance if one was not provided.

staticMatrix3.multiplyByScalar(matrix, scalar, result)Matrix3

Computes the product of a matrix and a scalar.
Name Type Description
matrix Matrix3 The matrix.
scalar Number The number to multiply by.
result Matrix3 optional The object onto which to store the result.
Returns:
The modified result parameter or a new Cartesian3 instance if one was not provided.

staticMatrix3.multiplyByVector(matrix, cartesian, result)Cartesian3

Computes the product of a matrix and a column vector.
Name Type Description
matrix Matrix3 The matrix.
cartesian Cartesian3 The column.
result Cartesian3 optional The object onto which to store the result.
Returns:
The modified result parameter or a new Cartesian3 instance if one was not provided.

staticMatrix3.negate(matrix, result)Matrix3

Creates a negated copy of the provided matrix.
Name Type Description
matrix Matrix3 The matrix to negate.
result Matrix3 optional The object onto which to store the result.
Returns:
The modified result parameter or a new Matrix3 instance if one was not provided.

staticMatrix3.setColumn(matrix, index, cartesian, result)Matrix3

Computes a new matrix that replaces the specified column in the provided matrix with the provided Cartesian3 instance.
Name Type Description
matrix Matrix3 The matrix to use.
index Number The zero-based index of the column to set.
cartesian Cartesian3 The Cartesian whose values will be assigned to the specified column.
result Cartesian3 optional The object onto which to store the result.
Returns:
The modified result parameter or a new Matrix3 instance if one was not provided.
Throws:
See:

staticMatrix3.setRow(matrix, index, cartesian, result)Matrix3

Computes a new matrix that replaces the specified row in the provided matrix with the provided Cartesian3 instance.
Name Type Description
matrix Matrix3 The matrix to use.
index Number The zero-based index of the row to set.
cartesian Cartesian3 The Cartesian whose values will be assigned to the specified row.
result Cartesian3 optional The object onto which to store the result.
Returns:
The modified result parameter or a new Matrix3 instance if one was not provided.
Throws:
See:

staticMatrix3.toArray(matrix, result)Number[]

Creates an Array from the provided Matrix3 instance. The array will be in column-major order.
Name Type Description
matrix Matrix3 The matrix to use..
result Number[] optional The Array onto which to store the result.
Returns:
The modified Array parameter or a new Array instance if one was not provided.

staticMatrix3.transpose(matrix, result)Matrix3

Computes the transpose of the provided matrix.
Name Type Description
matrix Matrix3 The matrix to transpose.
result Matrix3 optional The object onto which to store the result.
Returns:
The modified result parameter or a new Matrix3 instance if one was not provided.