Book Image

NumPy: Beginner's Guide

By : Ivan Idris
Book Image

NumPy: Beginner's Guide

By: Ivan Idris

Overview of this book

Table of Contents (21 chapters)
NumPy Beginner's Guide Third Edition
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
NumPy Functions' References
Index

Time for action – getting the present value


Let's reverse compute the present value with the numbers from the Time for action – determining the future value section:

Plug in the figures from the Time for action – determining the future value section:

print("Present value", np.pv(0.03/4, 5 * 4, -10, 1376.09633204))

This gives us 1000 as expected apart from a tiny numerical error. Actually, it is not an error but a representation issue. We are dealing here with outgoing cash flow, that is the reason for the negative value:

Present value -999.999999999

What just happened?

We did the reverse computation of the Time for action – determining the future value section to get the present value from the future value. This was done with the NumPy pv() function.