# Function rotationMatrix Create a 2-dimensional counter-clockwise rotation matrix (2x2) for a given angle (expressed in radians). Create a 2-dimensional counter-clockwise rotation matrix (3x3) by a given angle (expressed in radians) around a given axis (1x3). ## Syntax ```js math.rotationMatrix(theta) math.rotationMatrix(theta, format) math.rotationMatrix(theta, [v]) math.rotationMatrix(theta, [v], format) ``` ### Parameters Parameter | Type | Description --------- | ---- | ----------- `theta` | number | BigNumber | Complex | Unit | Rotation angle `v` | Array | Matrix | Rotation axis `format` | string | Result Matrix storage format ### Returns Type | Description ---- | ----------- Array | Matrix | Rotation matrix ### Throws Type | Description ---- | ----------- ## Examples ```js math.rotationMatrix(math.pi / 2) // returns [[0, -1], [1, 0]] math.rotationMatrix(math.bignumber(1)) // returns [[bignumber(cos(1)), bignumber(-sin(1))], [bignumber(sin(1)), bignumber(cos(1))]] math.rotationMatrix(math.complex(1 + i)) // returns [[cos(1 + i), -sin(1 + i)], [sin(1 + i), cos(1 + i)]] math.rotationMatrix(math.unit('1rad')) // returns [[cos(1), -sin(1)], [sin(1), cos(1)]] math.rotationMatrix(math.pi / 2, [0, 1, 0]) // returns [[0, 0, 1], [0, 1, 0], [-1, 0, 0]] math.rotationMatrix(math.pi / 2, matrix([0, 1, 0])) // returns matrix([[0, 0, 1], [0, 1, 0], [-1, 0, 0]]) ``` ## See also [matrix](matrix.md), [cos](cos.md), [sin](sin.md)