# Jacobi Matrix Calculation Routines

This section describes routines that compute the Jacobi matrix using central differences. Jacobi matrix calculation is required to solve nonlinear least squares problem and systems of nonlinear equations (with or without linear bound constraints). Routines for calculation of the Jacobi matrix have "Black-Box" interfaces, where users pass the objective function via parameters. Note that in this case the user’s objective function must have fixed interface.

Jacobi Matrix Calculation Routines
Routine Name | Operation
--- | ---
djacobi_init | Initializes the solver.
djacobi_solve | Computes the Jacobi matrix of the function on the basis of RCI using the central difference.
djacobi_delete | Removes data.
djacobi | Computes the Jacobi matrix of the fcn function using the central difference.

- djacobi_init
  Initializes the solver for Jacobian calculations.
- djacobi_solve
  Computes the Jacobi matrix of the function on the basis of RCI using the central difference.
- djacobi_delete
  Removes the data object required by the Jacobian calculation.
- djacobi
  Computes the Jacobi matrix of the user's objective function using the cenral difference.
- Examples of djacobi_solve Usage
- Examples of djacobi Usage

Parent topic: Optimization Solver Routines