Unfamiliar .D0 number syntax
32 views (last 30 days)
Show older comments
Chad Greene on 7 Mar 2022
Commented: James Tursa on 9 Mar 2022
I've inherited some Matlab code that was previously adapted from Fortran, and the Matlab code has a syntax I'm not familiar with. Numbers end with .D0, so I see a lot of lines like:
a = b*5.D0;
which produces the same result as
a = b*5;
I haven't found any documentation for this syntax, but it's easy to deduce what it's doing:
My questions are:
- What is this syntax called?
- Is there any particular reason to use it?
- Can I safely delete every instance of .D0 from this code I've inherited?
Steven Lord on 7 Mar 2022
This is E notation. I believe MATLAB supports D as well as E because Cleve was inspired by Fortran, which as a comment on that page states "FORTRAN (at least since FORTRAN IV as of 1961) also uses "D" to signify double precision numbers in scientific notation."
x = 3.4e2
y = 3.4d2
The .D0 indicates that whatever value you're defining is an integer. All of z, w, and q are the same value (five.)
z = 5.0D0
w = 5.D0
q = 5D0
James Tursa on 9 Mar 2022
@Chad Greene FYI, there is a difference between MATLAB and Fortran for the E notation. In MATLAB the E notation is a double variable same as D notation, but in Fortran the E notation is single precision, not double precision.
More Answers (0)
Find more on Fortran with MATLAB in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!Start Hunting!