Matrix.SetIdentity Method


Changes this Matrix structure into an identity matrix.

 void SetIdentity();
public void SetIdentity ();
member this.SetIdentity : unit -> unit
Public Sub SetIdentity ()


The following example shows how to turn a Matrix structure into an identity matrix.

private Matrix identityExample()

    // Get the identity matrix, which is equal to 
    // (1,0,0,1,0,0). 
    Matrix myMatrix = Matrix.Identity;

    Matrix m = new Matrix(1,0,0,1,0,0);

    return myMatrix;


An identity matrix has a value of 1 in coefficients [1,1],[2,2],[3,3] and a value of 0 in the rest of the coefficients. This correlates to setting M11 and M22 to 1 and M12, M21, OffsetX, and OffsetY to 0. In an affine matrix, which is the implementation that Windows Presentation Foundation (WPF) uses for the Matrix structure, coefficients [3,1],[3,2],[3.3] are implied to always have the values 0,0,1 respectively.

1 0 0
0 1 0
0 0 1

For an identity matrix, the ToString method returns the string "Identity", instead of the coefficients of the Matrix.

Applies to

See also