PICScript - Creating Your Own Scripts

PICScript is a powerful programming language that enables you to manipulate horizons or grids. A Horizon Script can even include statistics extracted from your seismic data.

You may create a PICScript by typing the entire script into the PICScript text window or by using automatic declarations and function buttons. Experienced programmers can write scripts in a flat text editor then load them to PICScript. For more information, see Building PICScripts Click by Click and PICScript for Programmers.

In either case, you will find the PICScript Manual useful. This manual, written by the programmer who developed PICScript, describes the syntax and use of PICScript declarations and functions. It is a PDF file so you can print a copy and keep it near your keyboard for reference. See Support Documents on the ProductName Help menu for the PICScript Manual.

"Aliases" represent surfaces and seismic attributes in scripts. This allows you to reuse the script with different inputs or in other projects by simply reassigning the aliases at run time. See Update Alias.

Aliases are assigned by entering a declaration into the script. Declarations identify input surfaces and seismic data, output surfaces, and temporary variables for use in the script functions. See Surface Declarations and Seismic Declarations.

Aliases may not begin with a number or be words "reserved" by PICScript for its own use. See Using Aliases.

Scripts create an output grid or horizon by processing surface Functions and seismic functions. In a grid script, input surfaces are grids created in the gridding module. (See Creating Horizon Grids.) In horizon scripts, surfaces are horizon values stored in the horizon database. Seismic Functions allow you to extract attributes or statistics over a window of seismic time.

A surface function may be an expression (or series of expressions) contained in a function block or a whole surface function. (dip, azimuth, and smoothing). Whole surface functions are stand alone and may not be used inside a function block.

A script may contain one or more functions. Each function creates a result. The result of a function may be the final output of the script or the result may be used in another function. For an example you can declare a temporary surface (surfacetemp ID) to store the results of a function and use it in another function. Global variables can also be used to accumulate values for use in functions.

You will declare an output attribute (type) when you construct a PICScript. The output attribute's name will be used as an alias in the script. The actual name of the output grid or horizon is assigned at "run time".

A horizon script can output a time, amplitude or both to the horizon database. Time results should be stored as time, all other horizon script results should be output as amplitude.

A grid script can output time, amplitude, interval velocity, average velocity, or depth. Grids of any other type should be output as amplitude.

Any line in a script that begins with two slashes is a comment line. Use these lines to place explanations and notes into your script. A well commented script is easier to use.

Comment lines are all ignored by the PICScript processor with one exception: script mode statements.

//GridScriptMode

//HorizonScriptMode

These comments are read by PICScript a saved file is opened to determine whether the script is a grid script or a horizon script. If a script does not have a script mode statement, you will have to select grid mode or horizon mode manually.