MATLAB Function Reference |
Syntax
Description
d = det(X)
returns the determinant of the square matrix X
. If X
contains only integer entries, the result d
is also an integer.
Remarks
Using det(X)
==
0
as a test for matrix singularity is appropriate only for matrices of modest order with small integer entries. Testing singularity using abs(det(X))
<=
tolerance
is not recommended as it is difficult to choose the correct tolerance. The function cond(X)
can check for singular and nearly singular matrices.
Algorithm
The determinant is computed from the triangular factors obtained by Gaussian elimination
Examples
The statement A = [1 2 3; 4 5 6; 7 8 9]
This happens to be a singular matrix, so d = det(A)
produces d = 0.
Changing A(3,3)
with A(3,3) = 0
turns A
into a nonsingular matrix. Now d = det(A)
produces d = 27
.
See Also
The arithmetic operators \
, /
depfun | detrend |
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