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.