i.pca should accept also group names as input (like r.out.gdal)

[neteler]

When analysing multispectral data, it is common and convenient to use an imagery group as input instead of a list of raster map names.

The r.out.gdal module supports both raster map and group names input, the same approach is desired for i.pca.

[mmetz]

Replying to neteler:

When analysing multispectral data, it is common and convenient to use an imagery group as input instead of a list of raster map names.

An imagery group as input is accepted as of r56494.

[hamish]

in the case of i.pca, do the order of map inputs matter? order within the group may be predictable, but is it guaranteed long-term?

Hamish

ps- AFAIK it's undocumented, but trac parses keywords on commas internally.

[mmetz]

Replying to hamish:

in the case of i.pca, do the order of map inputs matter? order within the group may be predictable, but is it guaranteed long-term?

The order does not matter for the output maps (PC scores), but does matter for the vectors (loadings), since each loading refers to a specific input band.

[martinl]

Seems to be already done

    input   Name of two or more input raster maps or imagery group

Closing, feel free reopen if needed.