Home
Reference Guides
Reference guides are available for functions and commands supported by OML, Tcl, and Python.
Reference Guide for OpenMatrix Language Functions
The Reference Guide contains documentation for all functions supported in the OpenMatrix language.
Linear Algebra Commands
issymmetric
Symmetric matrix test.

Welcome
What's New
Discover new features and enhancements.
Get Started
Discover Compose, including its language support and system requirements.
Tutorials
The Compose tutorials and associated example model files help introduce you to the basic functionality of the software.
User Guide
Learn about the features and functionality available in Compose.
Reference Guides
Reference guides are available for functions and commands supported by OML, Tcl, and Python.
- Scripting Guide for OpenMatrix Language
  OpenMatrix is a mathematical scripting language.
- Reference Guide for OpenMatrix Language Functions
  The Reference Guide contains documentation for all functions supported in the OpenMatrix language.
  - ABF Commands
  - Altair Integration Commands
  - Audio Commands
  - CAE Commands
  - CAE Reader Commands
  - CAE Reader 3D Commands
  - CAE Writer Commands
  - Calculus Commands
  - Computer Vision Commands
  - Communication Commands
  - Control System Commands
  - Core Minimal Interpreter Commands
  - Data Structure Commands
  - Differential Equations Commands
  - Elementary Math Commands
  - File I/O Commands
  - Geometry Commands
  - GUI Commands
  - HDF5 Reader Commands
  - HDF5 Writer Commands
  - hstpyfit Commands
  - Image Commands
  - JSON Commands
  - Library Manager Commands
  - Linear Algebra Commands
    - balance
      Returns a matrix with rows and columns of roughly equal magnitude.
    - bicgstab
      Solve a system of linear equations with the biconjugate gradient stabilized method.
    - chol
      Cholesky decomposition.
    - cond
      Compute the condition number of a matrix.
    - conv
      Convolution of two vectors.
    - conv2
      Compute 2D convolution.
    - cross
      Vector cross product.
    - ctranspose
      Matrix transpose.
    - det
      Compute the matrix determinant.
    - dot
      Vector dot product.
    - eig
      Eigen decomposition.
    - full
      Creates a fully populated matrix from sparse.
    - gradient
      Compute the gradient of a real function or sampled data.
    - gmres
      Solve a system of linear equations with the generalized minimum residual method.
    - hankel
      Computes the Hankel matrix.
    - inv
      Compute the inverse matrix.
    - isbanded
      Determines if the input is a banded matrix.
    - isdiag
      Determines if the input is a diagonal matrix.
    - ishermitian
      Hermitian matrix test.
    - issparse
      Determines if an input is a matrix with sparse storage.
    - issquare
      Determines if x is a square matrix.
    - issymmetric
      Symmetric matrix test.
    - istril
      Determines if the input is a lower triangular matrix.
    - istriu
      Determines if the input is a upper triangular matrix.
    - kron
      Kronecker matrix product.
    - kronprod
      Kronecker matrix product object.
    - ldl
      LDL decomposition.
    - linsolve
      Solve a linear system of equations.
    - lu
      LU decomposition.
    - nnz
      Finds the number of non-zero values in a matrix.
    - norm
      Compute matrix and vector norms.
    - null
      Compute an orthonormal basis for the nullspace of a matrix.
    - orth
      Compute an orthonormal basis for the column space of a matrix.
    - pcg
      Solve a system of linear equations with the preconditioned conjugate gradient method.
    - pinv
      Compute the matrix pseudo-inverse.
    - qr
      QR decomposition.
    - rank
      Compute the rank of matrix A.
    - rcond
      Compute the 1-norm estimate of the reciprocal condition number.
    - schur
      Schur decomposition.
    - sparse
      Sparse matrix creation.
    - speye
      Sparse identity matrix creation.
    - spones
      Set non-zero matrix elements to 1.
    - svd
      Singular value decomposition.
    - toeplitz
      Computes the Toeplitz matrix.
    - trace
      Compute the trace of a matrix, the sum of the diagonal elements.
    - transpose
      Matrix transpose.
    - tril
      Returns a lower triangular matrix.
    - triu
      Returns a upper triangular matrix.
  - Logical Commands
  - Machine Learning Commands
  - Optimization Commands
  - Plotting Commands
  - PSIM Commands
  - Polynomial Math Commands
  - Signal Processing Commands
  - Special Functions Commands
  - Statistical Analysis Commands
  - String Operations Commands
  - System Commands
  - Table Commands
  - Tcl Bridge OML Commands
  - Tcl Bridge Tcl Commands
  - Time Commands
  - Trigonometry Commands
  - OML to Python Bridge Commands
  - Python to OML Bridge Commands
- Python in Compose Reference Guide
Appendix
Get help for the optional libraries that are available in the Extension Manager.
Frequently Asked Questions
You've got questions? We've got answers!

issymmetric

Symmetric matrix test.

Syntax

R = issymmetric(A)

R = issymmetric(A,tol)

Inputs

A: The variable to test.
tol: The tolerance for the test (default 0).; Type: double; Dimension: scalar

Outputs

R: A logical 1 when A is a symmetric matrix, and 0 otherwise.

Example

Matrix example:

R = issymmetric([1,2,3;2,4,5;3,5,6])

R = 1

Comments

tol applies as follows:

norm(A-A','inf')/norm(A,'inf') tol.