Categorize Assay Values by Percent Range

Use the Geochem Analysis > Create %-Range Categorized Database menu option (CHRANGECATDB GX) to create a duplicate database from the current database and transform the values in the ASSAY channels to integer values 0 to N, based on N input percentile values and the values location in the range of data for each channel.

Categorize Assay Values by Percent Range dialog options

New database file name suffix

The new database name is created by taking the current database name and appending the suffix; e.g. "Test.gdb" becomes "Test_Cat.gdb" using the suffix "_Cat". The new database is created in the current project directory, not the location of the original database.

Script Parameter: CHRANGECATDB.SUFFIX

Zone minima (comma-separated)

Enter between 1 and 7 percentage values, separated by commas. These values are the minimum values of successive zones. The values must be monotonically increasing, e.g. "50,75,87,93,98". In this example, those values, when sorted, which fall below the 50th percentile will be transformed to 0, those 50 >= value > 75 will be transformed to 1, etc., and those >=98 will be transformed to 5.

Script Parameter: CHRANGECATDB.RANGES

Application Notes

This GX is useful for transforming data prior to doing multi-symbol plots such as with the CHROSE GX, since all the data is transformed into the same range and individual scaling is not required for each channel. In addition, even the largest values are transformed to last range (e.g. 5 for 5 input values), and so do not produce enormous petals in the plot.

A new copy of the existing database is produced in order to preserve the original ASSAY channel names and meta data, and prevent crowding of results (there may be dozens of ASSAY data channels)

The GX performs the following operations on each assay channel’s data:

All data in the channel in all selected lines is scanned and sorted to determine the equivalent values corresponding to the input percentage threshold values.
Each data value is given a value of zero if it is less than the smallest threshold value. Increasing integer values are awarded to values falling into the subsequent ranges. All values greater than or equal to the highest threshold value are changed to the integer corresponding to the last range.

Dummy values remain dummies on output.

Detection Limits

If a detection limit has been set for a channel (using the "Attributes…" GX on the right-mouse channel heading menu), then any value which is less than the detection limit will be given an output zone of 0. The detection limit value is stored in the "DETECTLIMIT" setting in the channel registry.