FunctionMod™ is a model manipulation and arithmetic tool for working with Jason Geoscience Workbench® (JGW) data files. It is also used as the calculation engine in Largo and the more complicated functions in Map View.

Complex functions can be created, including results that cascade into other computations, and functions that branch to one or more sub-functions. FunctionMod also comes with a number of preset functions, and we are adding more all the time. Examples include mean, median, root mean square, sum, standard deviation, and over 50 others. Boolean logic and vector operations are supported.

The functions that you create and save are called transforms. Rather than referencing a particular data file, the transform references a type of file (e.g., a trace file with impedance traces, or a horizon file with time horizons). This makes the transform portable, and you simply assign the appropriate files when you want to execute the transform.

Application examples include:

Calculating lithology logs using Boolean logic such as “If the resistivity is greater than X and the Gamma Ray is less than Y, assign pay sand. If the Resistivity is less than X and the Gamma Ray is less than Y, assign wet sand. Otherwise assign shale.”
Calculating derived parameters such as Poisson's Ratio and Lame parameters from P-Impedance and S-Impedance following a RockTrace™ Simultaneous AVA inversion.
Calculating mean and standard deviation volumes following a StatMod™ geostatistical inversion.
Calculating porosity and lithology probability models from StatMod™ results.

Important features include:

Input can be a combination of property data, well logs, horizons, trend models, depth/time, sample interval, coordinates, or even single values.
Vertical range of data is selected via a time gate, solid model, well top pairs, or wherever data are available.
Different functions can be applied to different areas defined by solid model layers or well top pairs.
Complex functions can be created and set up to cascade into other computations.