
dextract(1)                  Khoros                   dextract(1)

PROGRAM
     dextract - Extracts 1-D Subsignal(s)

SYNTAX
     dextract

     -i             input image

     -o             resulting output image

     [-x]           Starting point for data subset

     [-d]           data processing direction (0 = down vectors,
                    1 = across bands)

     [-e]           Extract rest of file
                                        -OR-

     [-l]           Specify length

     [-V]           Gives the version for dextract

     [-U]           Gives the usage for dextract

     [-P]           Prompts for command line options

     [-A [file1]]   Creates the answer file called dextract.ans
                    or file1

     [-a [file1]]   Uses dextract.ans or file1 as the answer file

DESCRIPTION
     dextract extracts 1-dimensional subsignals from the input
     data file.

     Dextract will extract N subsignal vectors from an input file
     of N signal vectors.  All vectors will be extracted starting
     from the same initial position (-x option), and all will be
     of the same length (-e or -l options).

     Dextract does not work on explicit location data and will
     return an error when such an image is encountered.  No out-
     put image will be created.  Dextract works only on
     VFF_TYP_FLOAT or VFF_TYP_COMPLEX data files.

     Starting Point The starting point (-x) option specifies the
                    offset into the data set where the first
                    point of the output sequence is.  The default
                    value is 0 (the first point of the input
                    series).

     Length of output sequence
                    Two mutually exclusive options are available
                    for specifying the length of the output
                    sequence, -e (logical) and -l (int).

                    The default option is the -e (extract to end
                    of sequence) option.  When this option is
                    selected, dextract calculates the number of
                    points to the right of the first point speci-
                    fied (-x), and the output file is assigned
                    this calculated length.

                    The other option available for specifying
                    output file length is is the -l (length)
                    option.  The -l option allows the user to
                    specify the length of the output sequence.
                    If the specified value is greater than the
                    input file length minus the index to first
                    point is specified, dextract returns an error
                    and exits.  The default -l value is 1.

     Process direction
                    Data can be processed with either band or
                    vector orientation (-d option). The default
                    data processing direction is in the band
                    direction (d = 1). This means that each band
                    is processed as a signal (instead of each
                    vector being a signal).  The direction of
                    processing can be changed so that data stored
                    in multiband format will be processed as vec-
                    tors, by setting the -d option to 0.  In
                    other words, the data is processed as a set
                    of data sequences, where each sequence
                    corresponds to a pixel location, and the
                    points of each sequence are defined by the
                    bands corresponding to that pixel location.

REQUIRED ARGUMENTS
     -i     type: infile
            desc: input image

     -o     type: outfile
            desc: resulting output image

OPTIONAL ARGUMENTS
     -x     type: integer
            desc: Starting point for data subset
            default: 0
            bounds: value >= 0

     -d     type: boolean
            desc: data processing direction (0 = down vectors, 1
            = across bands)
            default: true

     ***   These arguments are MUTUALLY EXCLUSIVE   ***
      If desired, you may provide ONE AND ONLY ONE of:

     -e     desc: Extract rest of file
            default: true

     -l     desc: Specify length
            default: 1
            bounds: value > 0

            ********

EXAMPLES
     dextract -i input_file -o extracted_file -x 18 -l 20

     Will return a file containing the subsignal(s) that are 20
     points long, starting at point 18 in the original image.

SEE ALSO
     intro(1), verror(3), vgparms(3), vutils(3), ldextract(3)

RESTRICTIONS
     Dextract works only on VFF_TYP_COMPLEX and VFF_TYP_FLOAT.

     Dextract does not work on explicit location data and will
     return an error when such a data file is encountered.

COPYRIGHT
     Copyright 1991, University of New Mexico.  All rights
     reserved.

Khoros                    Release: 1.0                          1

