Factor analysis

Command line

The Factor analysis operation can be directly executed by typing one of the following expressions on the command line of the Main window:

OUTMATRIX	=	MatrixFactorAnal(InputMaplist)
OUTMATRIX	=	MatrixFactorAnal(InputMaplist, nr of output bands)

where:

OUTMATRIX	is the name of the output matrix; the output map list will obtain the same name; the output raster maps also use this name followed by _1, _2, _3, etc.
MatrixFactorAnal	is the command to start the Factor analysis operation.
InputMaplist	is the name of the input map list; all raster maps in the input map list must use the Image domain or the same value domain, and have the same georeference. If you like you can also define a map list on the fly as: mlist(map1, map2, ...) where mlist is fixed syntax to define a temporary map list without name, and where map1, map2 etc. are the names of the raster maps that should be part of the map list.
nr of output bands	is an optional parameter to specify the number of desired output bands (1 <= integer value <= nr of input bands). If not specified, the same number of output bands will be defined as found in the input map list.

When the definition symbol = is used:

A dependent output matrix will be created containing the Factor Analysis coefficients.
A dependent output map list is automatically created (defined); it will contain the resulting transformed raster maps (factor maps). The definition of the output map list reads:

OUTMAPLIST

MapListMatrixMultiply(InputMapList, OUTMATRIX, nr of output maps)

When the assignment symbol := is used:

The dependency link of the output matrix will be immediately broken after the output matrix has been calculated.
The dependent map list will be created as above.

The dependent raster maps of the dependent output map list will only be calculated when the map list is opened, e.g. by double-clicking the map list in a Catalog.