Configuring SegyTracker








    The Config file


The above is a fairly complete example of a SegyTracker config file.

All lines starting with "#" are comments. Blank lines are ignored.

The first section defines a total of 46 columns of which 23 are flagged as False, meaning they will not be created. Flagging columns as false retains the column definition for future reference.

The first two columns, "Select" and "File Path" are mandatory. They must be defined for every table. All the other columns are optional

There are three types of columns that can be described in the config file

Predefined columns have a fixed name which cannot be altered. SegyTracker uses the colum name to determine how to populate the column. Predefined columns are defined by the key-word "Column:" followed by the True / False flag to denote whether the column will be created. The next field is the column name which, as stated above, is fixed. The name can consist of multiple words. In the case of columns which will display a floating point number, such as "Size MB", an additional field is required to set the number of decimal places that will be used to display the value.

For example to define a column to display the SEGY sample rate with one decimal place the defintion would look like

Column:  True   SRate   1

The second type of column is the user editable text column. This is a column that the user can use to enter text related to each row. An example would be the project the SEGY belongs to, or the processor name. Text can be copied and pasted into these columns.
The column definition has the key word "UserEditableColumn:" followed by the True / False flag followed by the column name which is set by the user.

To create an editable text column called "My Text Column" the definition would be

UserEditableColumn:   True   My Text Column

The third column type is the user defined column where the user sets the column name, the header to read the data from, along with the byte location and format.

The headers must be defined as one of:

EBCHEAD
BINARY
TRACE

The possible formats for the binary and trace headers are:

SINGLE_BYTE    8 bit integer
SHORT_INT        16 bit integer
LONG_INT          32 bit integer
IBM_FLOAT       32 bit floating point in IBM format
IEEE_FLOAT      32 bit floating point in IEEE format

The formats for reading the EBCDIC header are:

EBCDIC
ASCII

Note that all format and header keywords are upper case.

The following definition would create a column to display the shotpoint number from the first trace.

UserColumn:   True    First SP
Header     =     TRACE
StartByte    =    17
Format    =    LONG_INT

The keyword is "UserColumn" followed by the True / False flag followed by the column name "First SP". The "First" tells SegyTracker to read the value from the first trace. To read the minimum shotpoint value the name would be "Min SP". First, Last, Min, Max are the only special flags in user defined column names.
The "Header" record defines the header to read the data from. The "StartByte" and "Format" define the starting byte location and format of the data. The keywords must be spelled as above with attention to upper and lower case.


    Setting user preferences


The second section of the config file consists of user defaults mainly used for populating dialog boxes. These include byte locations and formats for data items like shotpoints and XYs. Most of these entries are self-explanatory or are described in the config file
Non-Canadian users should pay particular attention to the section on format codes. For Canadian data the codes, as defined by the CSEG are:

IEEE_FLOAT_CODE = 6
SINGLE_BYTE_CODE = 5

Which, when reading or writing a SEGY file would interpret a format code of 6 as IEEE float and a code of 5 as 8 bit integer or single byte format. The SEG however defines the codes as follows:

IEEE_FLOAT_CODE = 5
SINGLE_BYTE_CODE = 8

Which defines a code of 5 for IEEE float and 8 for single byte.


    Setting default directories


The final section of the config file defines default directories used as starting points for file browsers. These directories should be set by each individual user. The directories used by SegyTracker are:

JAR_DIR =    Directory where the SegyTracker.jar file and other support files are stored.
START_DIR    Directory where SegyTracker will begin searching for SEGY files.
CONFIG_DIR    Directory where config files can be imported or exported. Note: not where SegyTracker initially looks for a config file.
IMPORT_DIR    Directory from which files such as saved tables can be imported
EXPORT_DIR    Export directory for saved tables and other files.
HUGE_ARRAY_DIR   Directory used to create very large arrays if insufficient RAM available.


    The default config file


Upon startup SegyTracker will attempt to import a config file from the users home directory called SegyTracker_Config.cfg. Note upper case letters. If the file is not found SegyTracker will look in the JAR_DIR directory for the same file.

If it is still not found SegyTracker will create a default config file defining only the "Selected" and "File Path" columns. The directories will all be set to the current working directory.

Ideally each user will have a config file called SegyTracker_Config.cfg in their home directory which would contain their most commonly used column definitions, dialog defaults, and appropriate directory paths.

They can also have other config files, with unique names saved in, for instance, IMPORT_DIR, which they could use for specialized datasets. There is no limit to the number of config files a user can have.

To import a non standard config file select the "Columns" tab and click the "Import Column Configuration File" button, or select from the column menu. Select the config file with the file browser and the new configuration will be set. The configuration file can, and should, be imported before importing any SEGY data.

If the user only wants to use the standard configuration stored in their home directory the config file will be imported automatically on startup.

Config files can be created manually using a text editor, preferably editing an existing file. Pay particular attention to upper and lower case letters. They are almost always significant.

A better way to create a config file is to use the
Exporting a config file option