Inline Grid by N Values

Use the Inline Grid by N Values menu option (IPGRIDN GX) to subset an IP database based on "N" value, then to grid and display the grid to a new map.

Inline Grid by N Values dialog options

Channel to grid

Select a channel from the drop-down list.

Script Parameter: IPGRIDN.CHAN

Grid name

Select the output grid name.

Script Parameter: IPGRIDN.GRID

N Value

Select the N value for the grid. All data with this N value is subset to a new database for gridding. The list of values is created from those available in the selected lines in the current database. This works in parallel with the mask channel.

Script Parameter: IPGRIDN.N

Mask Channel

If selected, this channel can be used to mask the output. If the value in the mask channel is a dummy "*", then the corresponding value in the output channel will not be copied to the new database (the row is removed, not just dummied itself). This works in parallel with the "N" value.

Script Parameter: IPGRIDN. MASK: Default "QC"

Gridding Method

Select a gridding method. Once the subset database is created, the selected gridding GX dialog is displayed. You may then alter the various options for gridding.

Options are:

Minimum Curvature (RANGRID)

Bi-directional line gridding (BIGRID)

TIN gridding (TINGRID)

For TIN gridding, the TINDB GX is first called to create a TIN out of the subset data.

The default grid name is created using the channel name and the selected N value. For instance, using the "Vp" channel and N=2, a grid called "Vp_2.grd" is created. If a fractional N value is used, the decimal place is replace by an underscore, so Vp and N=2.5 gives the name "Vp_2_5.grd"

Script Parameter: IPGRIDN. METHOD: Default "M" (Minimum curvature)

Retain subset database?

By default, this working database is unloaded from the project and then deleted when the GX finishes creating the grid and displaying it to a new map.

The subset database name is created using the channel name and the selected N value. For instance, using the "Vp" channel and N=2, a database called "Vp_2.gdb" is created. If a fractional N value is used, the decimal place is replace by an underscore, so Vp and N=2.5 gives the name "Vp_2_5.gdb"

Script Parameter: IPGRIDN. SAVEDB: 0:No, 1:Yes; Default "No"

Application Notes

This GX automates a number of existing processes available in the IP and Gridding menus in order to grid data values with selected "N" values in an IP database.

In the first step the IPXY GX is called to create a subset database containing only data with the selected "N" value. This database contains only the current X and Y channels, and the channel to be gridded.

The subset database is made the current database, and the selected gridding GX (RANGRID, BIGRID, TIN gridding) is called. You may use the default grid name, created from the selected channel and N value, or enter your own grid name at this stage.

Finally, the grid is plotted to a new map, using the GRIDIMG1 GX.