NAME

       Gridall - Allows one to draw backgrounds for X/Y plots. Included are routines for drawing grids,
       perimeters, and pairs of axes. Internal parameters of Gridall control such things as the color indices
       and line width scale factors used to draw various parts of the background, the formats to be used for
       labels, the sizes of the characters to be used for labels, the amount by which labels are to be offset
       from the axes, and the routine to be called to draw the labels (the SPPS routine WTSTR or the Plotchar
       routine PLCHHQ).

SYNOPSIS

       Each of the routines GRID, GRIDL, HALFAX, PERIM, PERIML, and GRIDAL draws a background of some sort
       within the part of the plotter frame occupied by the current GKS viewport, as follows:

       •      GRID draws an unlabeled grid.

       •      GRIDL draws a labeled grid.

       •      HALFAX draws a pair of intersecting axes.

       •      PERIM draws an unlabeled perimeter.

       •      PERIML draws a labeled perimeter.

       •      GRIDAL draws any of the above.

       The  positioning  of  ticks  and  grid  lines is determined partly by the arguments of these routines and
       partly by the nature of the current mapping  from  the  "user"  coordinate  system  to  the  "fractional"
       coordinate  system,  as  determined  by the current definitions of the GKS viewport and window and by the
       values of two internal parameters of the package SPPS: ´LS´ and ´MI´. Numeric labels  reflect  values  in
       the "user" coordinate system.

       Note:  Calling  the SPPS routine SET defines the GKS viewport and window and the values of the parameters
       ´LS´ and ´MI´.  The parameter ´LS´ determines whether the mappings  of  user  coordinates  to  fractional
       coordinates  are linear or logarithmic and the parameter ´MI´ determines whether the mappings are mirror-
       imaged or not.

       Each of the internal parameters of Gridall has a three-character mnemonic name of the form ´xxx´. Each of
       the routines GAGETC, GAGETI, GAGETR, GASETC, GASETI, and GASETR is intended either to retrieve the  value
       of a specific internal parameter of Gridall or to give a new value to it, as follows:

       •      GAGETC is called with the name of an internal parameter of type CHARACTER and a character variable
              in which the value of the parameter is to be returned.

       •      GAGETI  is  called  with  the name of an internal parameter of type INTEGER or REAL and an integer
              variable in which the integer equivalent of the value of the parameter is to be returned.

       •      GAGETR is called with the name of an internal parameter  of  type  INTEGER  or  REAL  and  a  real
              variable in which the real equivalent of the value of the parameter is to be returned.

       •      GASETC  is  called  with  the  name  of  an  internal  parameter of type CHARACTER and a character
              expression that is to become the new value of the parameter.

       •      GASETI is called with the name of an internal parameter of type INTEGER or  REAL  and  an  integer
              expression that is to become the new value of the parameter.

       •      GASETR  is  called  with  the  name  of  an  internal parameter of type INTEGER or REAL and a real
              expression that is to become the new value of the parameter.

       These six routines allow one to access all of the internal parameters of Gridall in a  manner  consistent
       with  other NCAR Graphics utilities and are intended to replace some older routines, each of which allows
       access to a limited subset of the internal parameters. However, the older routines  are  still  available
       and will remain so for the foreseeable future:

       •      GACOLR  sets  the  value  of  internal  parameters  that control the color of various parts of the
              background.

       •      LABMOD sets the value of internal parameters that affect the appearance of labels.

       •      TICKS and TICK4 set the value of internal parameters that determine the length  and  direction  of
              ticks.

C-BINDING SYNOPSIS

       c_grid
       c_gridl
       c_halfax
       c_perim
       c_periml
       c_gridal
       c_gagetc
       c_gageti
       c_gagetr
       c_gasetc
       c_gaseti
       c_gasetr
       c_gacolr
       c_labmod
       c_ticks
       c_tick4

USER-MODIFIABLE INTERNAL ROUTINES

       None.

ACCESS

       To  use  Gridall  C  or Fortran routines, load the NCAR Graphics libraries ncarg, ncarg_gks, and ncarg_c,
       preferably in that order.

MESSAGES

       Various error conditions can occur in Gridall.  Each of these results in a  call  to  the  error-handling
       routine  SETER,  with  a  final  argument  indicating that the error is recoverable; by default, an error
       message is printed and execution is terminated, but, if you turn on error recovery (as described  in  the
       "man" page for "error_handling"), you can get control back.

       The error messages are as follows; all should be more or less self-explanatory.

            GACOLR - UNCLEARED PRIOR ERROR
            GAGETC - UNCLEARED PRIOR ERROR
            GAGETC - UNRECOGNIZED PARAMETER NAME
            GAGETI - UNCLEARED PRIOR ERROR
            GAGETR - UNCLEARED PRIOR ERROR
            GAGETR - UNRECOGNIZED PARAMETER NAME
            GASETC - UNCLEARED PRIOR ERROR
            GASETC - UNRECOGNIZED PARAMETER NAME
            GASETI - UNCLEARED PRIOR ERROR
            GASETR - UNCLEARED PRIOR ERROR
            GASETR - UNRECOGNIZED PARAMETER NAME
            GRID - UNCLEARED PRIOR ERROR
            GRIDAL - ERROR EXIT FROM GQCLIP
            GRIDAL - ERROR EXIT FROM GQLWSC
            GRIDAL - ERROR EXIT FROM GQPLCI
            GRIDAL - ERROR EXIT FROM GQTXCI
            GRIDAL - UNCLEARED PRIOR ERROR
            GRIDL - UNCLEARED PRIOR ERROR
            HALFAX - UNCLEARED PRIOR ERROR
            LABMOD - UNCLEARED PRIOR ERROR
            PERIM - UNCLEARED PRIOR ERROR
            PERIML - UNCLEARED PRIOR ERROR
            TICK4 - UNCLEARED PRIOR ERROR
            TICKS - UNCLEARED PRIOR ERROR

SEE ALSO

       Online:  gridall_params,  gacolr,  gagetc,  gageti,  gagetr, gasetc, gaseti, gasetr, grid, gridal, gridl,
       halfax, labmod, perim, periml, tick4, ticks, ncarg_cbind.

       Hardcopy: NCAR Graphics Fundamentals, UNIX Version

COPYRIGHT

       Copyright (C) 1987-2009
       University Corporation for Atmospheric Research
       The use of this Software is governed by a License Agreement.

UNIX                                               March 1993                                    Gridall(3NCARG)