Introduction

ACON - A CONtouring application - is a data visualisation application, which includes an embedded programming language and a number of intrinsic functions supporting fisheries assessment.

In addition to a library of built-in math functions, new analytical functions may be defined by the user to perform more complex calculations as required.

This program will assist in the visualization of data sets. Visual output includes:

• grey scale, RGB, or CMYK shaded contours, isolines
• data labels, data values, data symbols
• axes, grid lines
• text and drawing primitives
• overlay information (e.g. coastlines)
• animation of a sequence of images
• screen, and numerous graphical output file formats.

The user's data (in user's coordinates, e.g. longitude, latitude, catch) is read from ASCII data files and represented as needed. Data may also be read from ACON binary files (if previously saved), and directly from Oracle SQL databases (when running on a host with Oracle database software.)
Acon exists in two versions : ACON CONSOLE and ACON GUI.

More details below on how to run ACON on a VAX, Unix, or PC.

ACON CONSOLE

The console version is a command line interface version used for WWW server CGI applications. This version may also be used as a replacement for the DOS version where a GUI is not required. The Console version is typically used to run predefined scripts. The application interface is a DOS window used by the user to enter the data he wants to manipulate.

To perform the assessment calculations, the user typically enters the data and mathematical expressions in a dos window.
If the user types in a mathematical expression in the console window:
8000 8500 9000 + 100
and presses Enter at the end of the line of text, the expression is evaluated and the results printed in this same console window under the line entered by the user:
8100 8600 9100
Graphical output is usually drawn in a graphic file which must be defined before any drawing commands.
Acon Console is typically invoked as a CGI application.
See WWW CGI Interface in the Topics section, for more details.

ACON GUI

Acon GUI is a Windows95/98 compatible application which includes multiple editing windows and a menu driven interface. Most of the menu options allow for point and click access to common commands. Often, a pop up dialog box is displayed to enter the command's input parameters. See the individual command's documentation for details of its use. The GUI version allows the user to manipulate his data and generate graphics interactively using ACON commands.

To perform the assessment calculations, the user typically enters the data and mathematical expressions in a text-editing window (named Editor 1) and views the results in a text output window (Editor 2). Graphical output is usually drawn to a graphing window (Graph1).

If the user types in a mathematical expression in the Editor 1 window and executes the expression:
8000 8500 9000 + 100
the expression is evaluated and the results printed in the Editor 2 window:
8100 8600 9100
See Additional ACON GUI Functionality in the Topics section, for details on the specific use of the GUI version of ACON.

Introduction by example

The commands shown in this example are the script versions of the commands. When the version of ACON used supports menus, the menu items prompt the user for the parameters using standard dialogs and are easier to use, but not "reusable" as scripts are.

A data file is read using free format input, to define the x,y and z values for the data points. In this example 6 data points are read.

/* this is a comment - data file contains decimal degrees x,y values */
/* read the data file into a matrix "data" */
Matrix_Read("C:\testsuite\test_data.txt","Data");
/* we're not finished yet */
/* we can inspect the 5 columns of data we have read by printing it */
print(data)
-66.0 43.5 10 -65.0 43.5
-63.0 41.5 20 -63.5 42.0
-65.0 43.0 30 -66.2 43.5
-66.0 42.0 10 -65.0 43.0
-63.8 43.2 22 -64.0 41.0
-66.2 43.6 0 -65.0 42.2
...The limits of the plot are defined (e.g. longitude, latitude) and the position of the plot on the page. Note that in this document the position of the graphics on the page doesn't match the Data_Viewport position.

Data_Window(-67,-62,41,44); /* longitude latitude limits of plot */
Data_Viewport(mm(30),mm(110),mm(200),mm(270)); /* position on page */
Data_Projection("MERCATOR"); /* use mercator projection */
The axes are drawn on the page using a solid 0.5 mm wide line.

Line_Type(0); /* Line Type set to a solid line */
Line_Width(mm(0.5)); /* line width 0.5 mm */
Axis(1,1,0,0,1,0,1,0,0); /* draw a labeled axis */


The interpolation method and # of subtriangles are defined. The grey levels for data values to be shaded are defined.

/* inverse distance wt'd gradient */
Data_Interpolation(0,1.5);
/* 9 subtri. within delaunay triangles */
Data_Subtriangles(9);
/* grey level for each data level */
Data_Contour_Levels(15,0.75,20,0.5,25,0.2,30,0);
The data is plotted as a shaded contour plot using the established parameters.

/* plot as a shaded contour plot of the data in columns 1-3 of "data" */
Shade_Contours(data[;1 2 3]);


The Delaunay triangles (forming triangles between data points) which were used to calculate the surface, are shown.

/* draw delaunay triangles */
Delaunay_Triangles(data[;12 3]);


The z values for each data point used to generate the shaded surface are shown (the central point has a value of 30).

/* label the data points */
Data_Labels(data[;1 2 3]);


A 2 x 2 grid is drawn over the plot.

/* draw a grid on the plot */
Grid(2,2);


An overlay file containing the coordinates of the coastline of Nova Scotia is drawn (and clipped) to this plot window.

/* draw the NS coastline */
Overlay_file("COAST1");

Draw the edges of the triangulated data set.

/* set the line width */
Line_Width(pts(2.5));
/* draw the limits of the data set */
Data_Border(data[;1 2 3]);


Draw a data legend to show the data values corresponding to the shaded grey levels.

/* draw the data legend */
GreyScale_Legend(mm(90.00),mm(260.00)); /* specify upper left corner */


This is the end of this example. There are more examples available.

VAX and UNIX Environments

A Script file version of this program also runs under VMS on Dec VAX equipment or under UNIX on supported hardware. With this version, a Tektronix 4010/4014 screen driver replaces the Quickdraw graphics.
Some commands are not supported in the VAX version; e.g. QuickTime animation or Data Dialogs.

How to run the program on VAX and UNIX Environments

Using a Tektronix 4010/4014 (or emulator), run the program by invoking the DCL procedure (assuming one exists):
@ACON <example script file name>
where <example script file name> would be something of the form:
[black.script]test_script
The commands from the test script file will be read and executed.
The program output is listed in ACON.LIS, graphics are output to the screen.
When the plot is completed, you will be able to type QUIT to end the program.
Examine the script file and list file to review the command syntax and effect.

GhostScript may be used to preview PostScript or Illustrator output files (and convert these to other formats).

Win X compatible Environments

ACON GUI is the PC version of ACON data visualization program. ACON GUI is written using MicroSoft C++ Version 6.0.

Hardware requirements

There are no specific hardware limitations.

Software requirements

ACON GUI runs on Win 9x, XP, NT or newer platforms.

Obtaining the software

To download the GUI (on PC) version of ACON see Download The GhostScript postscript preview program is available on the internet.

Installation

Acon_gui and its associated files are stored in a self un-zippping exe file and must be decompressed before being used. The files are unzipped by default into a folder named ACON.

How to run the program on a PC

ACON_GUI is started by running ACON_GUI.exe found inside the Engine folder or by clicking on the shortcut provided in the ACON folder.

Scripts

The ACON folder contains a number of example scripts in the examples folder. They may be used to test your installation and as a starting point for your own script writing. They are executed by choosing the script from the Use Script File command or by opening a script file into a Editor window, selecting all of the text, and choosing Use Selected Text.

The commands from the test script file will be read and executed. The program output is listed in Editor 2, and graphics are output to the screen. When the plot is completed, you will be able to inspect the graphics.

Type QUIT to end the program, or Exit the program.
GhostScript may be used to preview PostScript or Illustrator output files (and convert these to other formats).

3rd party filter software may be used to convert Illustrator files into Microsoft Word metafiles.

Graphics in the graph window may be copied as metafiles and pasted into Word, or saved as metafiles using menu commands.