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Frequently Asked Questions:

Q: Has the SLATEC source been modified?
A: No. These are the version 4.1 SLATEC routines exactly as
provided by netlib.
Q: Why take only the double precision routines?
A: Many of the function evaluations in SLATEC are carried out
by truncated Taylor series expansions. The number of terms
retained in these expansions dictate that the single precision
routines are really only accurate for 32 bit floating point
arithmetic. The double precision routines are good for 64 bits.
On Cray systems, R8slatec is compiled to map double precision to
Cray single precision. Thus the library can be used in a REAL*8
code with portability between Cray and conventional 32 bit
workstation environments. A goal of the NTCC Modules Library
is to encourage portable fortran programming practices. There
is no hope for the portability of single precision codes, hence
the choice to include only the double precision (really, 64 bit)
SLATEC routines.
Q: Why take only the C category subset of SLATEC?
A: SLATEC includes a version of BLAS and other routines which are
better distributed by other means. In the case of BLAS in
particular, users should seek system provided routines that are
optimized to the local machine architecture.
Q: I have a code which makes single precision SLATEC calls. How
can I make use of this library?
A: This would only be practical in the context of converting your
code to REAL*8 precision. The NTCC Modules Library includes a set
of "portability tools" to facilitate this conversion. One of
the tools, inside the "ftoken" module, is a tool called "fgtok".
The R8slatec modules contains a file "slatec_r8.table" which
contains the mapping of SLATEC names from single to double
precision, in a format understood by fgtok. So,
fgtok -s slatec_r8.table
will convert all single precision SLATEC special function calls.
The conversion of fortran code to REAL*8 precision is highly
desirable, because the result is code which runs identically on
Cray and on workstation environments.
Q: where can I find documentation for these routines.
A: the source code comments give very precise definitions of the
interfaces of individual routines. For more general information
point your browser at "http://www.netlib.org/slatec/index.html".