# evaluate_expr function

(Shortest import: `from brian2.codegen.optimisation import evaluate_expr)`

brian2.codegen.optimisation.evaluate_expr(expr, ns)

  Try to evaluate the expression in the given namespace

  Returns either (value, True) if successful, or (expr, False) otherwise.

  Examples

      >>> assumptions = {'exp': DEFAULT_FUNCTIONS['exp'].pyfunc,
      ...                'inf': DEFAULT_CONSTANTS['inf'].value}
      >>> evaluate_expr('1/2', assumptions)
      (0.5, True)
      >>> evaluate_expr('exp(-inf)', assumptions)
      (0.0, True)
      >>> evaluate_expr('sin(2*pi*freq*t)', assumptions)
      ('sin(2*pi*freq*t)', False)
      >>> evaluate_expr('1/0', assumptions)
      ('1/0', False)