Yes, you are correct. In "C"/C++ conversion is automatic (or generates a
compiler error prompting you to "cast" to another type) if there is the
slightest chance you will unintentionally lose precision...
If I go to VB or Fortran I tend to get a lot of math errors (which are not
caught by the compiler, but in real world use!) until I remember to
compensate and control my code better... double precision is used by
"C"/C++ (the "double"(integer) and "float"(floating point) variables) also
(you are right, it is related to the size, in bytes(bits), of the math
variable(s) in question), no problem--it is just more transparent in C.
And, you are correct again, "precision" is only a matter of where you wish
to "quit", and "double-double-precsion" and greater are able to be done,
either as a function of the compiler, hard code a routine directy in
assembly language yourself, or the programmer can institute them in the high
level code...
Visual Basic, Fortan, COBOL (yuck!), Pascal, "C", etc, etc are usually only
a matter of syntax, style, speed and preference... "C" is just my personal
preference...

Years ago it was common for Basic/VB to constantly have issues with math
variables (actually, changes to the functions in the OS) in each new release
of windows, I live in the past... frown

Warmest regards,
John

"Roy Lewallen" wrote in message
...
John Smith wrote:
I could be wrong, and Roy will correct me if I am, but EZNEC seems to be
written in Visual Basic, or similar... might you need the run-time
libraries for an older edition?

No, that's not the problem -- it's due to DOS not being able to properly
determine the size of a large amount of RAM. And the DOS versions were
written with the MS BASIC Professional Development System, not Visual
Basic. Windows versions of EZNEC (v. 3.0 and 4.0) are written in Visual
Basic, except the calculating engines and a few speed-critical main
program routines which are written in Fortran.

And, he (Roy) mentions "double percision"--a nasty reality of basic (and
some Fortran compilers also), which seems to confirm my suspicions...

Double precision isn't a "nasty reality" -- it's simply a way of storing
floating point variables. Normal precision floating point variables are
stored in four byte words, and consequently have a resolution of about
seven significant decimal digits. Double precision variables require 8
bytes and have about 15 significant digits of resolution. Fortran
additionally has a complex data type which requires twice as much storage
space, since each variable of that type has two parts. Some compilers have
additional, higher precisions available. The program author can choose
which data type to use for each individual variable.

Roy Lewallen, W7EL