Program Specific Data

This chapter discusses files containing CUBE Analyst data. Topics include:

Screenline file

This file is required if SCRFIL = T.

The screenline file is used to supply link/turn count and confidence level data to CUBE Analyst.

There are two formats of the file supported. The original format (indicate by parameter WIDEND=2) just supports link counts. An alternative format (WIDEND=3) has an extra column to allow turning counts to be specified.

This section describes both formats:

Link count format

The format of the file containing just link counts is as follows:

Columns	Type	Contents
1	Character	S screenline record identifier
2 - 5	Integer	Screenline number
6 - 14	Integer	Anode of link
15 - 23	Integer	Bnode of link
24 - 33	Real	Link traffic volume count
34 - 40	Integer	Confidence level. A number between 1 and 10000, but usually in the range 1-100, that expresses the user’s confidence in the link traffic volume count. This is used only by CUBE Analyst.
41 - 58	Character	Screenline name, up to 18 characters (optional)
60	Integer	Direction code. For purposes of matrix estimation this must be set to 1
61 - 70	Integer	X-coordinate (optional) at which to display screenline name on the screen.
71 - 80	Integer	Y-coordinate at which to display screenline name on the screen.

Turning count format

The format of the file that supports turning counts is as follows:

Columns	Type	Contents
1	Character	S screenline record identifier
2 - 5	Integer	Screenline number
6 - 14	Integer	Anode of link/turn
15 - 23	Integer	Bnode of link/turn
24 - 32	Integer	Cnode of turn (leave blank for link counts)
33 - 42	Real	Link/Turn traffic volume count
43 - 49	Integer	Confidence level. A number between 1 and 10000, but usually in the range 1-100, that expresses the user’s confidence in the traffic volume count. This is used only by CUBE Analyst.
50 - 67	Character	Screenline name, up to 18 characters (optional)
70	Integer	Direction code. For purposes of matrix estimation this must be set to 1.

Notes:

If a screenline contains more than one link/turn, then CUBE Analyst calculates the screenline count as the sum of the counts for each link/turn in the screenline. Also, the screenline confidence level is set as the weighted average of the individual link/turn count confidence levels.
The file can contain a mixture of link and turning counts. For link counts, the Cnode should be left blank.
Comment records, which have an asterisk (*) in column one, may appear anywhere in the file.

Trip end file

This file is required if TRPEND = T.

The trip end file format for CUBE Analyst is therefore:

Columns	Type	Content
1 - 10	Integer	Zone Number
11 - 20	Real	Generations
21 - 40		unused
41 - 50	Real	Attractions
51 - 60	Integer	Confidence Level for Generations
61 - 70	Integer	Confidence Level for Attractions

Comment records, which have an asterisk (*) in column one, may appear anywhere within the file.

Coordinate file

The input coordinate file must be supplied if option NODLAB has been set to TRUE. The file supplies the correspondence between node numbers and their hierarchic equivalents.

The format of the file is summarized below:

Columns	Type	Content
*1 - 10	Integer	Node number (sequential)
11 - 20	Integer	X coordinate
21 - 30	Integer	Y coordinate
*31 - 40	Integer	Hierarchic node number
41 - 48	Character	Text for node; short label (optional)
49 - 80	Character	Text for node; long label (optional)

Notes:

Items marked * must be coded for hierarchic processing.
Sequential node numbers must be unique.
If hierarchic node numbers are being used then:
- Hierarchic node numbers must be unique.
- Columns 31-40 must be coded on each record.
Text labels should normally be left justified in their respective fields.
Blank records will be ignored.
Records with an asterisk (*) in column 1 will be treated as comment records.
Node coordinates are used by the graphics programs and are therefore optional.

Model parameter file

This file is required if MODPER = T.

This file contains data describing the model parameters and their attributes. It would not normally be constructed by the user, as on initiating a run of CUBE Analyst the model parameters take a default value, as shown in the table below.

However, at the end of the CUBE Analyst run a file is generated containing the new model parameters calculated. The amended file, or indeed the unedited file, can be re-input to CUBE Analyst to invoke a warm start; that is to continue the estimation process from where the last run finished.

The general format of the file is as follows:

Record	Description
Record one	Header record defining the number/type of parameters in the file.
The next ZONES records	Values for the A(i) parameters
The next ZONES records	Values for the B(j) parameters
The next SCREENLINE records	Values for the X(k) parameters
The next two records (if COSTM = T)	The a and b parameters of the Distribution Model

Where:

ZONES is defined as the number of zones in the matrix.
SCREENLINE is defined as the number of screenlines specified.

Note that comment records, which have an asterisk (*) in column one, can appear anywhere in the file.

The format of the individual record types is as follows:

First record: [Must not be edited]

Columns	Type	Content
1 - 23	Character	Model parameter file
24 - 31	Integer	Number of model parameters
32 - 39	Integer	Number of origin zones
40 - 47	Integer	Number of destination zones
48 - 55	Integer	Number of screenlines
56 - 63	Integer	1 if using cost data, otherwise 0.
64 - 77	Real	Value of objective function
78 - 91	Real	Step size
92 - 99	Integer	Number of iterations completed

Remaining records

Columns	Type	Content	Default if parameter not defined
1 - 8	Integer	Parameter number
10 - 22	Real	Parameter value	1.0
24 - 36	Real	Lower bound for parameter	0.1 E-6
38 - 50	Real	Upper bound for parameter	1.0 E10
52 - 64	Real	Scale factor for parameter	1.0
65 - 89		Reserved for CUBE Analyst
100 - 107

If the file is not supplied by the user then it is created by CUBE Analyst and the default values shown above are used for each of the model parameters.

If the second, third and fourth fields all have the same value then the parameter is deemed to be fixed at this value. It is a requirement of CUBE Analyst that:

At least one parameter must be free otherwise a fatal error is reported and the program will stop.
At least one parameter must be fixed. If not done by the user than CUBE Analyst will fix A(1).

An identical format file is created at the end of an CUBE Analyst run, but it will contain the revised parameter values in it. This is so that CUBE Analyst can be re-started from where the last run was finished if required, or used as a basis for fixing parameter values. Note that CUBE Analyst adds up to three extra columns on the end of each record which are for its own internal use. The information put there should not be edited by the user.

Local matrix control file

This file is required if DSTRCT = T. The format of the file is as follows:

Columns	Type	Content
1 - 10	Integer	Origin District
11 - 20	Integer	Destination District

Comments records, which have asterisk (*) in column one, may appear anywhere in the file.

District definition file

This file is required if DSTRCT = T or WARMST = T.

The user may affect the operation of the estimation according to the grouping of zones into origin and destination districts. The district definition file which is input to CUBE Analyst is a direct access file, and so it is not amenable to direct alteration by the user.

Intercept file

This file is required if INTCPT = T or WARMST = T.

Output by CUBE Analyst and CUBE Voyager HIGHWAY and PT, this binary file stores information on routings and screenlines in a concise format. Once established, it may be re-input to CUBE Analyst to save (substantial) processing times when CUBE Analyst is estimating or re-estimating for data where neither the routings or screenline locations definitions have been altered. This file cannot be edited by the user.

Note that there is also a text file version of the intercept file that can be output. Its purpose is for information only; it is not intended for subsequent input to CUBE Analyst or any other program. The file is written to if the file is named, and is generated from either the input or output binary intercept file, depending upon which is used. For each screenline it shows:

The number of intercepting I-J pairs.
A sub-header under the screenline for each origin I that has routes that intercept the screenline.
Under each origin, a list of pairs of numbers. The first number of the pair represents the destination zone J. The second number of the pair represents the percentage of traffic travelling from the origin to the destination that routes through the screenline.

Gradient search file

This file is required if WARMST = T.

This is a binary file output by CUBE Analyst which is re-read by CUBE Analyst when warm starting a run (WARMST = T). It contains information used by CUBE Analyst’s optimizer and cannot be edited by the user.