nhlf90
nhlf90 is a script that invokes the FORTRAN 90 compiler/linker with the proper NCAR Graphics LLU (low-level utility) and HLU (high-level utility) libraries. There are special options recognized by this script. All other arguments and options are identical to the "gfortran" or "f90" command on your particular machine; arguments that include quoted strings may have to be enclosed in single quotes.
If you don't want to use nhlf90, but you want to see what libraries it pulls in, you can type "nhlf90" on the command line to see what gets included in the link line. You can then you can add this information to your own Makefile or script.
In order to run nhlf90, you must have your NCARG_ROOT environment variable set to the directory pathname where the NCAR Graphics libraries, binaries, and include files were installed. If you are not sure what NCARG_ROOT should be set to, please check with your system administrator, or send email to ncl-talk.
Note that, on some systems, if you supply your own binary libraries in
addition to the ones automatically referenced by
See also nhlf77 or
nhlcc for compiling Fortran 77
or C programs.
See ng4ex for a script that provides you
with access to tons of Fortran HLU example programs.
The script resides in $NCARG_ROOT/bin. You can either edit it directly
(be careful if you do this, especially if other people are using it),
or you can copy it to your own directory and modify it as necessary.
It's a C-shell script that is pretty easy to follow.
Some things you might want to change are:
The compiler used:
Fortran compile options:
C-to-Fortran libraries needed, or to add a "-L" path to the given
libraries:
List of cairo libraries:
List of NetCDF libraries:
Links in the NCAR Graphics ngmath library.
Links in the cairo libraries. This is necessary if you want
your graphical output to go to the cairo PS, PDF, or PNG output
formats.
Links in the netCDF library. This library is not part of NCL, so
check with your system administrator if you need it installed. You
can obtain a copy of it on the
Unidata NetCDF website.
Use this option for compilers that appear to be having trouble
initializing blockdata variables. It will cause a small subroutine to
be linked in that helps force the loading of blockdata initialization
routines. This should no longer be an issue in version 5.1.1 or later.
Just like with the "-ncarbd" option, use this option for compilers
that appear to be having trouble initializing Ngmath-related blockdata
variables. It will cause a small subroutine to be linked in that helps
force the loading of Ngmath blockdata initialization routines.
Note: this option doesn't need to be specified separately if you are
already including the "-ncarbd" and "-ngmath" options.
To compile an HLU Fortran 90 program called "xy06f.f" that depends on
the NetCDF library, type:
This will create an executable called "a.out".
Modifying nhlf90
It is possible to modify nhlf90 directly if you need to change
anything from the compiler it's using, compiler options, libraries
being linked in, etc.
set f77 = "gfortran"
set loadflags = "-fPIC -fno-range-check "
set f77libs = "-lgfortran"
set cairolib = "-lcairo -lfontconfig -lpixman-1 -lfreetype -lexpat"
set extra_libs = "$extra_libs -lnetcdf -lcurl -lhdf5_hl -lhdf5 -lsz -lz"
Options
Examples
To compile an HLU Fortran 90 program called "cn01f.f" and create
an executable called "cn01f", type:
nhlf90 -o cn01f cn01f.f
nhlf90 xy06f.f -netcdf