# Introducing PoPy

## Overview

PoPy’s features include:-

- Nonlinear mixed-effect models

- Bolus and infusion dosing regimens

- Inter-occasion variability

- Continuous and categorical likelihoods

- PK and PD models

PoPy consists of a powerful set of Command Line Tools and script files, to enable you to analyse a PK/PD data file quickly and efficiently, whilst minisimising errors due to an elegant and intuitive syntax.

PoPy makes it easy to fit models to data, but also has the ability to generate new data to test hypothetical scenarios.

## Documentation Structure

See Table 1 for layout of this documentation:-

Table 1 PoPy Documentation Structure
Section | Contents
--- | ---
Getting Started Guide | Read this first to get familiar with PoPy
Principles of Pharmacokinetics | A summary of individual PK/PD models using PoPy syntax
Population Models in PoPy | A summary of population PK models using PoPy syntax
PoPy Example Models | Examples of using PoPy for PK/PD analysis
PoPy for Nonmem Users | Guidance for converting Nonmem examples to PoPy
PoPy Reference Guide | A comprehensive reference on PoPy tools and scripts
Appendices | Links to PK/PD terms used throughout this guide.

## System Requirements

PoPy is currently available as a 64 bit Microsoft Windows binary. See Table 2:-

Table 2 System Requirements for PoPy
Operating System | Microsoft Windows 7.0/8.0/10.0
Disk Space Required | 1.5Gb
Bit Size | 64
Processor | Intel Core i3 and better recommended
Binary Installer Size | ~250Mb

## Abbreviations

FOCE

  first order conditional estimation

IMP

  importance sampling

ITS

  iterative two stage

IV

  Intra-venous, i.e. injected directly into a vein

JOE

  joint optimisation and estimation

LAPLACE

  Laplace approximation

ND

  none derivative estimation

OBJV

  objective function value

ODEs

  ordinary differential equations

PK/PD

  Pharmacokinetic/Pharmacodynamic

SAEM

  stochastic approximation expectation maximisation

TSLD

  Time since last dose

VPC

  visual predictive check

wrt

  With respect to - usually defines rate of change variable in an ordinary differential equation