Matrix Functions - zward/Amua GitHub Wiki

Matrix Functions

The following matrix functions are available. Matrix functions turn maroon in the formula bar.

Function	Name	Description	Arguments
chol	Cholesky Decomposition	chol(X): Returns the Cholesky Decomposition (lower triangle) of X	X: Symmetric positive definite (SPD) matrix
det	Determinant	det(X): Returns the determinant of X	X: Square matrix
diag	Matrix Diagonals	diag(X): Returns the diagonal elements of X as a row vector	X: Square matrix
iden	Identity Matrix	iden(n): Returns an identity matrix of size n	n: Size of identity matrix (Integer >0)
interpolate	Linear Interpolation	interpolate(x,X,Y): Returns a linear interpolation of Yat x	x: x-value at which to calculate interpolated value of y X: Row vector of x values (in increasing order) Y: Row vector of corresponding y values
inv	Inverse Matrix	inv(X): Returns the inverse of X using LU decomposition	X: Square, non-singular matrix
ncol	Number of Columns	ncol(X): Returns the number of columns in X	X: Matrix
norm	Matrix Norm	norm(X): Returns the Frobenius norm of X	X: Matrix
nrow	Number of Rows	nrow(X): Returns the number of rows in X	X: Matrix
renorm	Renormalize	renorm(X): Returns a row vector with the elements of X linearly renormalized to sum to 1.0	X: Row vector of real numbers >0
rep	Replicate	rep(x,n): Returns a row vector of size n filled with x	x: Real number to replicate n: Vector size (Integer >0)
seq	Sequence	seq(a,b): Returns a row vector containing a sequence of numbers from a to b with default step size 1.0seq(a,b,∆): Returns a row vector containing a sequence of numbers from a to b with step size ∆	a: Start of sequence (inclusive), real number b: End of sequence (inclusive if step size allows), real number ∆: Step size, real number >0 (optional)
softmax	Softmax Function (Normalized Exponential)	softmax(X): Returns a row vector with the exponentiated elements of X renormalized to sum to 1.0	X: Row vector of real numbers
stack	Stack Row Vectors	stack(X_1, X_2, ..., X_n): Returns a matrix of stacked row vectors	X_1 to X_n: Row vectors
tp	Matrix Transpose	tp(X): Returns the transpose of X	X: Matrix
tr	Matrix Trace	tr(X): Returns the trace (i.e. sum of diagonal elements) of X	X: Square matrix