tricon

Process Help

TRICON - generate contours from point or DTM data

Process Name	Menu Path	Link to Command Table
TRICON	Command line only	Click here

Introduction
Files, Fields and Parameters
Notes
Example
Errors

Introduction

Generates contours directly from irregularly scattered data points or from a triangulated digital terrain model as produced by TRIANR.

How to use

Contours are either simple unsmoothed straight-lines interpolated within the triangles, or are smoothed using the parametric quadratic Overhauser curve with linear blending function. The contours produced will be annotated in either case.

Files, Fields and Parameters

Input Files

Name	Description	I/O Status	Required	Type
IN	Optional input data file. Must contain fields X, Y, VALUE.	Input	No	Undefined
WIREPT	Optional input wireframe point file.	Input	No	Wireframe Points
WIRETR	Optional input wireframe triangle file.	Input	No	Wireframe Triangle
PROTO	Plot prototype file. Must contain the fields X, Y, S1, S2, CODE (numeric, explicit) and XMIN, XMAX, YMIN, YMAX, XSCALE, YSCALE (numeric, implicit). If these last 6 values set in PROTO , then corresponding parameters need not be set. If no plot prototype file, then XMIN, XMAX, YMIN, YMAX taken from the model file on IN.	Input	Yes	Plot Prototype

Output Files

Name	I/O Status	Required	Type	Description
PLOT	Output	Yes	Plot	Output plot file.

Fields

Name	Description	Source	Required	Type	Default
X	X co-ordinate field in input file.	IN	No	Numeric	Undefined
Y	Y co-ordinate field in input file.	IN	No	Numeric	Undefined
VALUE	Field to be contoured.	IN	No	Numeric	Undefined

Parameters

Name

Description

Required

Default

Range

Values

VMIN

Minimum contour value.

Yes

Undefined

VMAX

Maximum contour value.

Yes

Undefined

CINT

Contour interval.

Yes

Undefined

DMAX

Maximum separation of points to be joined.

Undefined

SURFACE

Optional surface identifier. +1 for upper surface, -1 for lower surface (+1).

-1, 1

OPTIMISE

Linear or quadratic contour tracing; =0 linear; =1 quadratic (0).

0,1

BOUNDARY

Option	Description
0	no boundary plotted; =1 boundary of data area plotted.

Undefined

0,1

DUPELIM

Set to 1 to allow elimination of duplicate points (0).

0,1

TOL

Tolerance distance below which points are considered to be duplicated (0.00001).

0.00001

Undefined

NDP

Number of decimal places for annotation (0).

Undefined

CHARSIZE

Character size in millimeters (3).

Undefined

ASPRATIO

Aspect ratio, width / ht. for chars (0.9).

0.9

Undefined

Colour [as 'pen' number] for plot (1).

Undefined

APPEND

Plot append flag. If set to 1 then the new plot will be appended to the PLOT file, if it exists and is a valid plot file (0).

0,1

XMIN

Minimum value of X for plot. None of XMIN, XMAX, YMIN, YMAX, XSCALE, YSCALE need be set if this information is already in the prototype.

Undefined

XMAX

Maximum value of X for plot.

Undefined

YMIN

Minimum value of Y for plot.

Undefined

YMAX

Maximum value of Y for plot.

Undefined

XSCALE

X scale in user data units per millimeter.

Undefined

YSCALE

Y scale in user data units per millimeter.

Undefined

Notes

In any one run of TRICON, input may come either from an &IN file or from a pair of &WIREPT,&WIRETR files, but not from a combination of the two. If it is required to update a digital terrain model with new point data, the process TRIUPD should be used before TRICON.
If @DUPELIM = 1, the following message is displayed:

nnnnnnnn DATA POINTS ACCEPTED AFTER ELIMINATION OF DUPLICATES

Example

!TRICON

&WIREPT(TOPOPT),&WIRETR(TOPOTR),&PROTO(TOPOPROT),
&PLOT(TOPOCONT),@VMIN=150,@VMAX=250,@CINT=5,
@DUPELIM=1

Error and Warning Messages

Message	Description	Solution
>>> XMIN, XMAX = nnnnnnnnnn.nn nnnnnnnnn.nn >>>YMIN, YMAX = nnnnnnnnnn.nn nnnnnnnnn.nn >>>XSCALE, YSCALE = nnnnnnnnnn.nn nnnnnnnnn.nn	Either insufficient scale information had been entered (at least two of XMIN, XMAX, XSCALE or Y equivalents must be entered either from the prototype of from parameters) or the combination given of XMIN, XMAX, and XSCALE (or their Y equivalents) was impossible. Often caused by entering a null plot prototype and no parameters. Fatal; the process is exited.

>>>CANNOT APPEND TO NON-EXISTENT OUTPUT FILE. >>>A NEW OUTPUT FILE WILL BE CREATED.	The @APPEND parameter has been set to 1, but the specified plot file does not exist. A new file will be created to contain the new plot being produced.

>>>ERROR - CANNOT APPEND TO PLOT FILE AS IT DOES >>>NOT CONTAIN ALL THE REQUIRED FIELDS. >>>HE PLOT FILE WILL BE OVERWRITTEN.	The @APPEND parameter has been set to 1, the specified plot file exists but is invalid. The existing plot file will be overwritten by the new plot being produced.

>>> ERR 121 <<< ( n) IN TRICON	An error has occurred when reading the input raw data, point or triangle file. Fatal; the process is exited.

>>>TRIANGLE FILE DEFINED, BUT >>>NO ASSOCIATED POINT FILE	Fatal; the process is exited.

>>>POINT FILE DEFINED, BUT >>>NO ASSOCIATED TRIANGLE FILE	Fatal; the process is exited.

>>>FIELD aaaaaaaa MISSING FROM POINT FILE	One of the essential fields XP, YP, ZP or PID is missing from the input wireframe point file. Fatal; the process is exited.

>>>FIELD aaaaaaaa MISSING FROM TRIANGLE FILE	One of the essential fields PID1, PID2, PID3, TRIANGLE or SID is missing from the input wireframe triangle file. Fatal; the process is exited.