Help from within the Unix shell

From the Unix shell you can get help from the on-line help library. Use the command

   % fighelp

and navigate through the hierarchy of information in the help library. You can also specify topics and sub-topics as command parameters. The command

   % fighelp istat

returns

ISTAT

     *********************************************************************
     *                             I S T A T                             *
     *  ISTAT examines an image, or a rectangular subset of an image or  *
     *  spectrum, and outputs a number of statistics about it, such as   *
     *  maximum and minimum value, mean and sigma, etc.  The results     *
     *  are used to set Figaro user variables, so can be used by Figaro  *
     *  procedures.  There are a number of examples in the documentation *
     *********************************************************************

  Additional information available:

  PARAMETERS            SOURCE_COMMENTS

Often the most extensive and interesting information is in the sub-topic `source_comments'.

The command

   % fighelp istat para image

returns

ISTAT
  PARAMETERS
    IMAGE
          TYPE    FILE
          NAME    IM(AGE)
          OPTIONS INPUT
          PROMPT  "(IMage) Name of image to examine"
          TEXT    ------------------------------------------------
                  IMAGE is the name of the image (or spectrum) for
                  which statistics are to be determined.
                  ------------------------------------------------

You can also get `run-time' help: When a command prompts you for some additional information and you have no idea what it's on about, try responding with a question mark. You will then get some help on that parameter of that command, and are re-prompted for the parameter. Observe this:

% istat
IMAGE - (IMage) Name of image to examine /@demo/ > ?

ISTAT
  PARAMETERS
    IMAGE
          TYPE    FILE
          NAME    IM(AGE)
          OPTIONS INPUT
          PROMPT  "(IMage) Name of image to examine"
          TEXT    ------------------------------------------------
                  IMAGE is the name of the image (or spectrum) for
                  which statistics are to be determined.
                  ------------------------------------------------

IMAGE - (IMage) Name of image to examine /@demo/ >
XSTART - (XStart) First X value to be used /0.5/ >
XEND - (XEnd) Last X value to be used /2039.5/ >

X-range 1 (0.5000) to 2040 (2039.5)
Total (over 2040 pixels) = 37751.6
Max   = 764.51   in pixel (849,1)
Min   = -0.12577 in pixel (149,1)
Mean  = 18.506
Sigma = 48.3061