CCG_SM1x

Combines data lines using a sigma-clipped median

Description:

This routine accepts an array consisting a series of (vectorised) lines of data. The weighted mean and standard deviation of each input column in STACK is then used to estimate the range of values which represent the required sigma clipping. Values outside of this range are then rejected and then the median of the remaining values is returned in the array RESULT. The variances are propagated through the combination processand returned in the RESVAR array.

Invocation

CALL CCG_SM1x( NSIGMA, NPIX, NLINES, STACK, VARS, MINPIX, COVEC, NMAT, RESULT, RESVAR, WRK1, WRK2, POINT, USED, NCON, NBAD, STATUS )

Arguments

NSIGMA = REAL (Given)
The number of sigma at which to reject data values.
NPIX = INTEGER (Given)
The number of pixels in a line of data.
NLINES = INTEGER (Given)
The number of lines of data in the stack.
STACK( NPIX, NLINES ) = ? (Given)
The array of lines which are to be combined into a single line.
VARS( NPIX, NLINES ) = ? (Given)
The data variances.
MINPIX = INTEGER (Given)
The minimum number of pixels required to contribute to an output pixel.
NMAT = INTEGER (Given)
Size of the first dimension of COVEC.
COVEC( NMAT, NLINES ) = DOUBLE PRECISION (Given)
The packed variance-covariance matrix of the order statistics from a normal distribution of sizes up to NLINES, produced by CCG_ORVAR.
RESULT( NPIX ) = ? (Returned)
The output line of data.
RESVAR( NPIX ) = ? (Returned)
The output variances.
WRK1( NLINES ) = ? (Returned)
Workspace for calculations.
WRK2( NLINES ) = ? (Returned)
Workspace for calculations.
POINT( NLINES ) = INTEGER (Returned)
Workspace to hold pointers to the original positions of the data before extraction and conversion in to the WRK1 array.
USED( NLINES ) = LOGICAL (Returned)
Workspace used to indicate which values have been used in estimating a resultant value.
NCON( NLINES ) = DOUBLE PRECISION (Given and Returned)
The actual number of contributing pixels.
NBAD = INTEGER (Returned)
The number of bad values in the output array created while forming the statistics. It excludes those bad values whose corresponding values along the collapse axis are all bad.
STATUS = INTEGER (Given and Returned)
The global status.

Notes: