**Syntax**

` >>> CENTERED`

**Parent Command**

` >> JACOBIAN`

**Subcommand**

` -
`

**Description**

This command calculates elements of the Jacobian matrix by means of centered finite difference quotients:

The evaluation of the Jacobian thus requires (2n+1) TOUGH2 simulations, where n is the number of parameters. The size of the perturbation dp can be controlled using command `>>> PERTURB.` Centered finite differences are more accurate than forward finite differences, but computationally twice as expensive (also see command `>>> FORWARD).`

**Example**

` > COMPUTATION
>> JACOBIAN
>>> use CENTERED finite difference quotient
>>> PERTURBation factor is : 0.005 times the parameter value
<<<
<<`

**See Also**

` >>> FORWARD (j) | >>> PERTURB
`