This functions transform a comparison or otherwise
logical value to a numeric value for use in a pim.
Usage
P(x)
PO(x, y = NULL)
Arguments
x
for P, a logical value. For PO a numeric value.
y
a numeric value or NULL. If NULL, the function
will try to calculate PO(L(x),R(x)), provided the functions
L and R are defined correctly. This
is the case when PO is used in the context of a probabilistic
index model fitted with pim.
Value
A numeric value of 0, 0.5 or 1. 1 if x < y, 0.5 if x == y
and 0 if x > y
Details
These functions are constructed purely for notation.
P is completely equivalent
to as.numeric, apart from an extra control
to check whether it actually makes sense to do so.
The function PO is just short for P(x < y) + 0.5*P(x == y)
See Also
pim and pim.formula for more information
on how this is used inside a pim context.