| MATLAB Function Reference | Search Help Desk |
| cond | See Also |
Condition number with respect to inversion
c = cond(X)
c = cond(X,p)
The condition number of a matrix measures the sensitivity of the solution of a system of linear equations to errors in the data. It gives an indication of the accuracy of the results from matrix inversion and the linear equation solution. Values of cond(X) and cond(X,p) near 1 indicate a well-conditioned matrix.
c = cond(X)
returns the 2-norm condition number, the ratio of the largest singular value of X to the smallest.
c = cond(X,p)
returns the matrix condition number in p-norm:
norm(X,p) * norm(inv(X),p
If p is... |
Then cond(X,p) returns the... |
1 |
1-norm condition number |
2 |
2-norm condition number |
'fro' |
Frobenius norm condition number |
inf |
Infinity norm condition number |
cond (when p = 2) uses the singular value decomposition, svd.
condeig Condition number with respect to eigenvalues
condest 1-norm matrix condition number estimate
norm Vector and matrix norms
rank Rank of a matrix
svd Singular value decomposition