presentValueSchedule¶

Evaluates the present value for a schedule of cash flows. It is not necessary that the cash flows be periodic.

Synopsis¶

presentValueSchedule (rate, values, dates)

Required Arguments¶

float rate (Input): Interest rate.
float values[] (Input): Array of size count of cash flows.
struct tm dates[] (Input): Array of size count of dates cash flows are made. For a more detailed discussion on dates see the Usage Notes section of this chapter.

Return Value¶

The present value for a schedule of cash flows that is not necessarily periodic. If no result can be computed, NaN is returned.

Description¶

Function presentValueSchedule computes the present value for a schedule of cash flows that is not necessarily periodic.

It can be found by solving the following:

$\sum_{i=1}^{count} \frac {\mathit{value}_i} {(1+\mathit{rate})^{\left(d_i-d_{\mathit{1}}\right)/365}}$

In the equation above, $d_i$ represents the i-th payment date, $d_1$ represents the 1st payment date, and $value_i$ represents the i-th cash flow.

Example¶

In this example, presentValueSchedule computes the present value of 3 payments, $1,000, $2,000 and $1,000, with an interest rate of 5% made on January 3, 1997, January 3, 1999 and January 3, 2000.

from __future__ import print_function
from numpy import *
from datetime import date
from pyimsl.math.presentValueSchedule import presentValueSchedule

rate = 0.05
values = [1000., 2000., 1000.]

dates = [date(1997, 1, 3),
         date(1999, 1, 3),
         date(2000, 1, 3)]

xnpv = presentValueSchedule(rate, values, dates)
print("The present value of the cash flows is $%.2f." % (xnpv))

Output¶

The present value of the cash flows is $3677.90.