NAME

resavg -- Average entries in a reseau table.

USAGE

resavg inres outres ientry oentry option

DESCRIPTION

This task averages the reseau positions in a list of entries in a reseau table and writes the result as a new entry, either in the input table or in an output table. The output table may be new, or output can be appended to an existing table.

PARAMETERS

inres = "" [file name]

Input reseau table (mandatory).

ientry = "" [string]

List of entries to be averaged. If ientry = "*", ALL entries in the table will be averaged.

outres = "" [file name]

Output reseau table (optional). If no output table name is specified, output will be appended to the input table.

oentry = "" [string]

Name to be given to the output entry.

option = "average" [string, allowed values: average | clip | median]

Type of averaging to be carried out.

average - Mean value <x> = (sum of x's)/(number of x's) etc.

clip - `clipped' average. Like "average" except that points more than 1.5 standard deviations from the mean are rejected and the average is recalculated with only the `good' points. (This method should not be used if the input reseau file contains less than 5 entries).

median - returns the median X-position and the median Y-position (calculated separately) for each reseau position in the table.

(setindef = no) [boolean]

Set invalid positions to INDEF?

This parameter works in conjunction with devlim. If setindef=yes, any reseau position with a mean scatter greater than devlim will be set to INDEF. Note: Any reseau mark which has no measured positions (i.e., is INDEF in all of the input entries) will automatically be labelled as INDEF in the output, regardless of the value of setindef.

(devlim = 3.) [real, min=0., max=INDEF]

Maximum allowed mean error (in pixels) for a valid position. This parameter is only used when setindef=yes.

(mdevfmt = ) [real]

Output value (written by the task to the parameter file) giving the mean scatter for all valid reseau positions (i.e., those not set to INDEF) on the current run.

(nindef = ) [integer]

Number of reseau positions set to INDEF in the output table. This is a task output parameter.

(verbose = yes) [boolean]

Print the results for each position to the screen?

This output can be piped to a file using the standard "... > filename.lis" syntax. For each reseau position the following parameters are printed: reseau number, mean X, mean Y, mean error, number of points used, and whether set to INDEF.

EXAMPLES

1. This example takes a reseau table, "respos", and does a clipped average of all of the entries in it. Any points with a mean error greater than 2.5 pixels are set to INDEF. The averaged output entry, "clipavg", is appended to the input reseau file and the terminal output is piped to "clipset.lis".

cl> resavg respos "" * clipavg clip setindef=yes devlim=2.5 > clipset.lis

BUGS

REFERENCES

This task was written by David Baxter.

SEE ALSO

Type "help focgeom option=sys" for a higher-level description of the focgeom package.