deletions | additions       diff --git a/Framework.tex b/Framework.tex  index 8c2927e..3d79e53 100644  --- a/Framework.tex  +++ b/Framework.tex 
...
\section{A Framework built on pandas}  \label{framework} \label{sec:framework}  There are several motivations for building an analysis framework around the \code{pandas DataFrame}.   The guiding principle underlying the design of this framework is to enable exploratory investigation. 
...
Our memory-efficient approach to data access is outlined in Section \ref{fileIO}, and our handling of unit conversions and coordinate transformations is discussed in Sections \ref{units} and \ref{coordinates}, respectively.  \subsection{Organizational Structure}  \label{hierarchy} \label{sec:hierarchy}  \subsubsection{Particle Dataframes}  \label{sec:df}  Data for each particle type (e.g., dark matter, gas, etc.) is stored in a separate DataFrame and indexed by particle ID number.   Individual fields can be loaded into the dataframes and deleted at will, with coherent slicing across multiple data fields, courtesy of \code{pandas}.   The base \code{PartType} objects, \code{PartTypeNbody} and \code{PartTypeSPH}  \subsubsection{\code{Snapshot}}  \label{sec:snap}  These DataFrame objects, loaded as needed from disk, are then gathered in a snapshot object, along with the header information, and any other snapshot-specific metadata.   \subsubsection{\code{Simulation}}  \label{sec:sim}  Metadata relevant to the simulation as a whole is then gathered in a simulation class, which also implements batch processing methods.  \subsection{Data Access}  \label{fileIO} \label{sec:fileIO}  \subsection{Units and physical constants}  \label{units} \label{sec:units}  Physical constants are imported from astropy, where necessary. Unit conversions are dealt with in a similar manner; unfortunately pandas DataFrames do not play nice with astropy quantities, and so the unit system included here is rudimentary at best.  \subsection{Coordinate Transformations}  \label{coordinates} \label{sec:coordinates}  pyGadget includes a coordinate module for converting between cartesian, spherical, and cylindrical coordinates, linear coordinate translation, and arbitrary axis rotation.