Show Database Channel Statistics

Use the Database Tools > Reports > Mark Statistics option (STAT GX) to calculate statistics for the currently selected data in the database.

This tool can be run from the database spreadsheet window and is also available with the Acquisition extension (under Tie Line Levelling > Levelling Utilities).

In the spreadsheet window:

Select (highlight) a database channel using one of the following methods:

Click once to select the channel.
Double-click to select the current line data for the channel.
Triple-click to select the entire database channel.

Right-click the selected channel to open the context menu.
Select Statistics to open the Mark Statistics dialog.

Mark Statistics dialog options

Channel	Displays the currently selected channel. For array channels, the selected data window range is appended to the channel name (for example, IP [0 to 29]).
Line(s)	Displays the currently selected line or lines.
Fid range	Displays the fiducial (FID) range of the selection.
Number of items	The total number of data values in the selection, including dummy or blank values.
String channel–specific fields These fields are displayed when the selected channel is of a string data type.
Number of non-blank items	The number of non-blank, non-numeric values in the selection.
Number of blank items	The number of blank values in the selection.
Number of numeric items	The number of numeric values in the selection. This field is always displayed for string channels, even when no numeric values are present (in which case the value is 0).
Numeric channel–specific fields These fields are displayed when the selected channel is of a numeric data type.
Number of valid items	The number of valid values (excluding dummy values) in the selection. Lines that contain no valid data (that is, lines without valid points) do not contribute to this count.
Number of dummies	The number of dummy values in the selection.
Statistical measures The following fields are available when numeric data is present in the selection:
Minimum	The smallest valid data value in the selection.
Maximum	The largest valid data value in the selection.
Range	The difference between the maximum and minimum values (Maximum − Minimum).
Mean	The arithmetic mean (average) of valid data values (the sum of all valid values divided by the number of valid items).
Median	The middle (central) value of the sorted data. Half of the values in the selection are above this value and half are below. For an even number of samples, this is the average of the two middle values.
Mode	The most frequently occurring value in the selection (if one exists). Otherwise, a mode of zero is reported.
Standard deviation	The square root of the variance, indicating how much the data values spread out from the mean.
Standard error	A measure of how accurately the selected data represents the true data spread. A larger sample size decreases the standard error, making results more reliable.
Variance	The average of the squared deviations from the mean. Like standard deviation, it is a measure of variability and indicates the degree of spread in the selected data.
Skew	A measure of the degree of asymmetry in the selected data: Positive (right) skew: mean > median Negative (left) skew: mean < median Zero skew: symmetric distribution
Kurtosis	An indicator of the sharpness/tailedness of the distribution: Positive kurtosis (> 0): The distribution is heavy-tailed, with more extreme outliers than a normal distribution. Negative kurtosis (< 0): The distribution is sharp, with fewer extreme outliers. Zero kurtosis (≈ 0): The distribution has a tail profile similar to a normal distribution.
Arithmetic sum	The sum of all valid data values in the selection.
Additional fields for drillhole databases These fields appear only when working with from–to drillhole interval data.
Length-weighted mean	Values are weighted by interval length (difference between DH_To and DH_From). Intervals with dummy values are excluded. An asterisk (*) following the value indicates that one or more holes were skipped in a multi-hole selection due to mismatched fiducial start or increment values between the channels.
Length	The total interval length, calculated as the sum of (DH_To − DH_From) for all non-dummy values. An asterisk (*) following the value indicates that one or more holes were skipped in a multi-hole selection due to mismatched fiducial start or increment values between the channels.

[Save Stats]	Click this button to open the Save Stats dialog and export the statistical report to a file.

Save Stats dialog options

New statistics file

Specify the output file name and location. Use Browse to select a folder.

Application Notes

The STAT GX generates statistics for marked and displayed data, including:

The selected cell
The selected channel for the current line
All lines in the database

Displayed values may differ from stored values if the data has been resampled to a different fiducial increment than it was originally stored. For example, if a channel has no data for a given line, it may appear filled with dummy values because, for display purposes, it is resampled to match the full length of the master FID channel.

For this reason, statistics reported here may differ from those generated by the line/channel report (XYZSTAT GX).

Values from geographic-format channels are displayed using geographic formatting.

Basic statistics (minimum, maximum, range, mean, median, and mode) are reported using the number of decimal places shown in the database (full precision is used in exported reports).
Advanced statistics (standard deviation, standard error, variance, skew, and kurtosis) are reported to at least three decimal places, or the number of decimals displayed in the database if that is greater.

When calculating statistics for the entire database, only stored values are used.

Scripting

This GX can be executed in script mode to produce a text file containing the calculated statistics.

Scripting Options

Channel

Channel to compute statistics for.

Script Parameter: STAT.CHAN

File

Output file for the statistics report.

Script Parameter: STAT.FILE

Array Statistics

Statistics for array channels can be calculated for:

All elements
Current window elements
A user-defined range of elements (start and end indices; indexing starts at zero)