# npv

npv(stream,
discountRate, initialValue, factor, timeStep)
is the system
dynamics function
that returns the net present value of stream
computed using discountRate. The initial
value is determined by initialValue
(usually 0) and the value is reported after multiplying by factor (usually 1).

Example:

npv can
be called
in formulas of system dynamics variables.

#### Units:

stream
-> units

discountRate -> 1/time

initialValue ->
units*time

factor -> dimensionless

timeStep -> time

npv()
-> units*time

#### Related topics

npve