Distance is very modular - it is made up of a large number of semi-independent components written in a variety of development environments (programming languages). These components interact through sets of well-defined interfaces. Many of the components are implemented as ActiveX components - OCXs, DLLs, EXEs etc. and the interaction is largely through calling public methods, setting public properties, etc. Others (e.g. the MCDS, MRDS and DSM analysis engines) are stand-alone executables or libraries and the interaction with these is largely through writing to and reading from text files.

These components have been written by us, for which we have access to the source code, and which we are responsible for maintaining.

The components fall into one of three types:

  • Microsoft Visual Basic 6 DLLs, OCXs and executables - GUIs, numerical engines (e.g. design engine), database engine, etc.
  • Compaq Visual Fortran executables - MCDS analysis engine.
  • R libraries - MRDS and DSM analysis engines.

In what follows, all components are VB6 unless otherwise stated.

Component / File Description
Distance for Windows Distance for Windows GUI and entry point for user
Database API and engine Manages project files and data files
Numerical engine (NEngine) Runs designs and analyses etc.
DnnnnDesEng.dll Design and survey NEngine
MCDS.exe MCDS and CDS NEngine - Fortran executable
Ec.exe Execute program and capture standard output and errors - used to invoke MCDS.exe
dsm_2.2.3.zip DSM NEngine - R library
dsm.support.r Support functions for calling dsm
mrds_2.1.5.zip MRDS NEngine - R library
mrds.support.r Support functions for calling mrds
support.r Support functions for calling R libraries
Numerical engine interfaces (NEI) One per NEngine, these provide an interface between the NEngines and the Numerical Server. They interpret text definitions (e.g. data filter and model definition), extract relevant data from the database, put it into an appropriate format for the NEngine, writing appropriate command files for the NEngine, run the NEngine and monitor progress, etc.
IDnnnnNEng.dll NEI type library - implemented by all NEIs
DnnnnDesNEI.dll Design engine NEI
DnnnnSvyNEI.dll Alternate design engine NEI used for generating single surveys (as opposed to running designs to estimate coverage)
DnnnnNEIUtil.dll NEI utilities
Numerical server  
DnnnnNSvr.dll Manages NEngine runs (queues them, runs them, resets them, etc). It either calls the appropriate NEI (e.g. design engine interface) or it creates an NEngine host which in turn calls the appropriate NEI (e.g. MCDS, MRDS, DSM). In the former case, the NEI runs in the same process as the numerical server (and the GUI); in the latter case, it runs in a separate process, allowing users to work with the GUI while the NEngine Interface is running.
NEngine host  
DnnnnNEH.exe Provides an indirect method the Numerical Server can use to call NEIs so that they run out of process.
Properties dialogs Pluggable GUI components to allow users to specify options - one per NEngine plus others
DnnnnDesPrp.ocx Design properties
DnnnnSvyPrp.ocx Survey properties
DnnnnDFPrp.ocx Data filter properties
DnnnnMDPrp.ocx Model definition properties - container for CDS and MRDS properties
DnnnnCDSPrp.ocx CDS analysis engine properties
DnnnnMRDSPrp.ocx MRDS analysis engine properties
DnnnnDSMPrp.ocx DSM analysis engine properties
Details pages Pluggable GUI components to allow users to view logs and results of runs - one per NEngine plus others
DnnnnDesDet.ocx Design details
DnnnnSvyDet.ocx Survey details
DnnnnCDSDet.ocx CDS analysis engine details
DnnnnDSMDet.ocx DSM analysis engine details
DnnnnMRDSDet.ocx MRDS analysis engine details
Wizards Additional GUI functionality
DnnnnIDWiz.dll Import Data wizard
DnnnnSPWiz.dll Setup Project wizard
DnnnnMap.ocx GIS map display control
DnnnnLegend.ocx GIS map legend control
DnnnnUtil.dll Utilities for strings, files, random numbers
CTmr4.dll High-resolution code timer, improved replacement for Microsoft’s timer control
CDlg3.dll Common dialog, improved replacement for Microsoft’s common dialog control
LogStr3.dll Log string class, for appending strings within Log windows
PrjParams6.dll Projection Parameters dialog, for editing GIS projection parameters
CSDesc3.ocx Co-ordinate system description
LLine3.ocx Labels with 3D lines
LogWin3.ocx Log window
SList4.ocx Section list - efficient drop-down combo box for long lists
GenerateLicenseKey.exe Executable to generate license keys for components. This is not shipped but is needed when developing new analysis engines.