8.7.7. PsdVar¶

class PsdVar¶

Represents a positive semi-definite variable. PsdVar is a square matrix of plain variables. It implies a constraint, that is, its solution must be a positive semi-definite matrix. A PsdVar can be multiplied by the matrix to obtain a PsdExpr. For example:

x = model.addPsdVar(dim = 2, name = "x")
expr = x * numpy.identity(x.dim)

Properties

index

The index position of the PSD variable

index¶: The index position of the PSD variable.

Methods

`getAttr()`	Obtain the attribute value of a PSD variable
`sameAs()`	Test whether the PSD variable is the same as another PSD variable
`setAttr()`	Set the attribute value of a PSD variable

getAttr(attrname)¶

Obtain the attribute value of a PSD variable.

Parameters: attrname – Attribute name

example:

m = Model()
x = m.addPsdVar(dim = 1)
print(x.dim)
print(x.getAttr(MDO.Attr.Dim))

Note

Attributes can also be read and written directly through object attributes; in this case, the attribute name is case-insensitive.

sameAs(var)¶

Test whether the PSD variable is the same as another PSD variable.

Parameters: var – Another PSD variable to be tested
Returns: A bool result

example:

m = Model()
x = m.addPsdVar(dim=1)
print(x.sameAs(m.getPsdVars()[0]))

setAttr(attrname, attrvalue)¶

Set the attribute value of a PSD variable.

Parameters

attrname – The name of the attribute.
attrvalue – The value of the attribute to be set.

example:

m = Model()
x = m.addPsdVar(dim = 1)
x.setAttr(MDO.Attr.PsdVarName, "x0")
print(x.psdvarname == "x0")

Note

Attributes can also be read and written directly through object attributes; in this case, the attribute name is case-insensitive.