pystra.model.LimitState#

class LimitState(expression=None)[source]#

Bases: object

The Limit State function definition class.

The limit state function can be defined in two main ways:

1. Numerical differentiation (FFD): the limit state function need only return its value at a set of evaluation points, X. In this form, the function can be either:

  1. A python lambda object;

  2. A python function object.

2. Using the Direct Differentiation Method (DDM): the limit state function is a python function object return both its value and gradient vector at each of the evaluation points.

Note in both cases that each parameter (i.e. function argument) may be passed as a vector, depending on the algorithm being called.

Where a function returns a gradient vector, it is only utilized when DDM is specified.

Methods

compute_lsf

Compute the limit state function

evaluate_ddm

evaluate_ffd

evaluate_lsf

Evaluate the limit state

evaluate_nogradient

getExpression

setExpression

Attributes

expression

Expression of the limit-state function
expression#

Expression of the limit-state function

evaluate_lsf(x, stochastic_model, analysis_options, diff_mode=None)[source]#

Evaluate the limit state

compute_lsf(x, ddm=False)[source]#

Compute the limit state function