p = xpress.problem()
p.setControl('miprelstop', 1e-4)
p.setControl({'feastol': 1e-4, 'presolve': 0})

1. As mentioned in the previous chapter, there is an alternative way to set and retrieve controls. It works by querying the data structure controls of each problem or, if one wants to set a control to be used by all problems defined subsequently, the global control object xpress.controls.

2. This function can be used in two ways depending on whether one wants to set one or more controls. In the first case, the arguments form a pair (string, value) where the first element is the lower-case name of a control (see the Xpress Optimizer reference manual for a complete list of controls). In the second case, the argument is a Python dictionary whose keys are control name string and whose values are the value of the control.