<s>
EAS3	B-Language
(	O
EAS	O
=	O
Ein-Ausgabe-System	O
)	O
is	O
a	O
software	O
toolkit	O
for	O
reading	O
and	O
writing	O
structured	O
binary	O
data	O
with	O
geometry	O
information	O
and	O
for	O
postprocessing	O
of	O
these	O
data	O
.	O
</s>
<s>
It	O
is	O
written	O
in	O
Fortran	B-Application
and	O
C	B-Language
and	O
runs	O
on	O
all	O
POSIX	O
operating	O
systems	O
.	O
</s>
<s>
The	O
libraries	O
include	O
different	O
numerical	O
algorithms	O
and	O
subroutines	O
for	O
reading	O
and	O
writing	O
files	O
in	O
the	O
binary	O
EAS3	B-Language
file	O
format	O
.	O
</s>
<s>
The	O
read/write	O
routines	O
are	O
provided	O
in	O
Fortran	B-Application
and	O
C	B-Language
.	O
Implemented	O
numerical	O
methods	O
include	O
,	O
for	O
example	O
,	O
Fast	O
Fourier	O
transform	O
,	O
Thomas	B-Language
algorithm	I-Language
and	O
interpolation	B-Algorithm
routines	O
.	O
</s>
<s>
The	O
libraries	O
are	O
also	O
suitable	O
for	O
vector	B-Operating_System
computers	I-Operating_System
.	O
</s>
<s>
EAS3	B-Language
has	O
been	O
developed	O
at	O
the	O
Institut	O
für	O
Aerodynamik	O
und	O
Gasdynamik	O
(	O
IAG	O
)	O
of	O
the	O
University	O
of	O
Stuttgart	O
.	O
</s>
<s>
Typically	O
,	O
simulations	O
were	O
,	O
and	O
are	O
still	O
today	O
,	O
performed	O
on	O
a	O
high-performance	B-Architecture
computer	I-Architecture
and	O
afterwards	O
postprocessed	O
on	O
other	O
machines	O
of	O
opposite	O
endianness	O
.	O
</s>
<s>
Since	O
the	O
publication	O
of	O
EAS3	B-Language
in	O
the	O
1999	O
,	O
the	O
software	O
has	O
been	O
developed	O
continuously	O
by	O
members	O
of	O
the	O
involved	O
institutes	O
.	O
</s>
<s>
Since	O
2007	O
,	O
EAS3	B-Language
is	O
also	O
available	O
via	O
the	O
heise	O
software	O
directory	O
.	O
</s>
<s>
EAS3	B-Language
is	O
used	O
by	O
applications	O
within	O
the	O
European	O
PRACE	O
project	O
.	O
</s>
<s>
The	O
EAS3	B-Language
file	O
format	O
is	O
used	O
to	O
store	O
floating	O
point	O
data	O
in	O
IEEE	O
format	O
and	O
to	O
exchange	O
the	O
files	O
between	O
different	O
computer	O
architectures	O
(	O
little/big	O
endian	O
)	O
.	O
</s>
<s>
file	O
system	O
)	O
,	O
EAS3	B-Language
files	O
are	O
suitable	O
for	O
large	O
simulations	O
and	O
thus	O
for	O
high-performance	B-Architecture
computing	I-Architecture
.	O
</s>
<s>
The	O
actual	O
EAS3	B-Language
executable	O
is	O
a	O
command-line	O
interface	O
for	O
alteration	O
of	O
EAS3	B-Language
files	O
.	O
</s>
<s>
As	O
the	O
commands	O
are	O
read	O
from	O
standard	O
input	O
,	O
EAS3	B-Language
may	O
be	O
used	O
in	O
shell	O
scripts	O
for	O
automated	O
calls	O
.	O
</s>
<s>
The	O
sources	O
can	O
be	O
obtained	O
directly	O
from	O
the	O
CVS	B-Application
repository	O
or	O
one	O
may	O
download	O
a	O
zipped	O
tar	O
file	O
.	O
</s>
<s>
As	O
linking	O
of	O
object	O
files	O
,	O
created	O
with	O
different	O
Fortran	B-Application
compilers	O
can	O
cause	O
problems	O
,	O
binary	O
packages	O
(	O
RPM	B-Application
,	O
.deb	O
)	O
are	O
not	O
offered	O
up	O
to	O
now	O
.	O
</s>
<s>
supercomputers	B-Architecture
.	O
</s>
<s>
cylindrical	O
coordinates	O
,	O
can	O
be	O
stored	O
in	O
EAS3	B-Language
files	O
but	O
the	O
existing	O
postprocessing	O
commands	O
may	O
not	O
be	O
used	O
.	O
</s>
<s>
As	O
the	O
usually	O
used	O
visualization	O
programs	O
do	O
not	O
support	O
the	O
EAS3	B-Language
file	O
format	O
directly	O
,	O
it	O
is	O
often	O
necessary	O
to	O
convert	O
the	O
data	O
to	O
the	O
corresponding	O
file	O
format	O
.	O
</s>
<s>
Commands	O
in	O
the	O
EAS3	B-Language
program	O
are	O
given	O
by	O
a	O
text	O
interface	O
,	O
a	O
graphical	O
user	O
interface	O
does	O
not	O
exist	O
.	O
</s>
<s>
Completion	O
of	O
the	O
commands	O
in	O
the	O
EAS3	B-Language
command	O
line	O
provides	O
support	O
for	O
interactive	O
usage	O
but	O
for	O
an	O
extensive	O
help	O
,	O
the	O
descriptions	O
on	O
the	O
webpage	O
are	O
necessary	O
.	O
</s>
<s>
EAS3	B-Language
is	O
published	O
under	O
the	B-License
MIT	I-License
License	I-License
.	O
</s>
<s>
The	B-License
MIT	I-License
License	I-License
is	O
a	O
free	O
software	O
license	O
originating	O
at	O
the	O
Massachusetts	O
Institute	O
of	O
Technology	O
(	O
MIT	O
)	O
.	O
</s>
<s>
Specifically	O
,	O
it	O
is	O
a	O
GPL-compatible	O
permissive	O
license	O
,	O
meaning	O
that	O
it	O
permits	O
reuse	O
within	O
proprietary	O
software	O
on	O
the	O
condition	O
that	O
the	O
license	O
is	O
distributed	O
with	O
that	O
software	O
.	O
</s>
