libgrafx11-1-gfortran binary package in Ubuntu Focal s390x

 CERNLIB is a suite of data analysis tools and libraries created for
 use in physics experiments, but also with applications to other
 fields such as the biological sciences.
 .
 This package includes libgrafX11, also known as HIGZ (High-level Interface
 to Graphics and ZEBRA), an interface to the X Window System. In addition
 to basic drawing functions, HIGZ includes a PostScript interface.
 .
 Note that in order to compile and link programs against this library,
 you must also install the libgrafx11-1-dev package.

Source package