1 Channel Lookup

Use the Database Tools > Database Utilities > 1 Channel Lookup menu option or the Tie Line levelling > Levelling Utilities > Table Lookup menu option, (LOOKUP1 GX), to scan values from a Geosoft table based on a single reference channel.

1 Channel Lookup dialog options

Table	The lookup table name. Script Parameter: LOOKUP1.TABLE
Reference channel	Database reference channel name. Script Parameter: LOOKUP1.REFCHAN
Table reference field	Table reference field. If not specified, the reference channel name is used. Script Parameter: LOOKUP1.REFERENCE
Output channel	Database output channel name. Script Parameter: LOOKUP1.OUTCHAN
Table output field	Table output field to place in the output channel. If not specified, the output channel name is used. Script Parameter: LOOKUP1.OUTDATA
Interpolation method	Interpolation mode: (See Application Notes for more information.) "exact" "nearest" "interpolate" "nearest close" "interpolate close" Script Parameter: LOOKUP1.INTERP
Search mode	Table search mode: "linear" for linear up or down search. "binary" for binary search. Script Parameter: LOOKUP1.MODE
Nominal spacing	The nominal spacing determines the distance below which the "interpolation close" and "nearest close" options are applied. The default setting is calculated using the second index fiducial. Script Parameter: LOOKUP1.SPACING

Application Notes

Note that the ‘/=’ lines at the top of the lookup table are necessary as they are part of the Geosoft Table format. You cannot have more than the exact number of columns in a lookup table since each field defined by ‘/=’ is related to each column in sequential order. See below for a description of each mode.

Interpolation methods:

"exact"	Finds exact table matches only. Values that do not match are set to dummy.
"nearest"	The result is set to the nearest value.
"interpolate"	The result is interpolated between table values.
"nearest close"	The result is set to the nearest value, but only if the reference value is within the nominal reference channel spacing. Other values are set to dummy.
"interpolate close"	The result is interpolated between lookup values, but only if the reference value is within the nominal reference channel spacing. Other values are set to dummy.

Search Mode

Use "linear" if the reference channel data is ordered, either up or down. For ordered data, a linear search will be up to four times faster than a binary search.

Use "binary" if the reference channel data is randomly ordered. A "Binary" search can be very much faster than a linear search when the data is randomly sorted.