.. _method-nl2sol-absolute_conv_tol:

"""""""""""""""""
absolute_conv_tol
"""""""""""""""""


Absolute convergence tolerance


.. toctree::
   :hidden:
   :maxdepth: 1



**Specification**

- *Alias:* None

- *Arguments:* REAL

- *Default:* -1. (use NL2SOL internal default)


**Description**


``absolute_conv_tol`` (NL2SOL's
``afctol``) is the absolute function convergence tolerance (stop when half
the sum of squares is less than ``absolute_conv_tol``, which is mainly
of interest on zero-residual test problems).

The internal default is a function of machine epsilon
(as limited by ``function_precision``). The default is selected with a value of -1.