Hi,
I am developing a Fortran code that uses HDF5. The Fortran API datatypes listed
at https://www.hdfgroup.org/HDF5/doc/RM/PredefDTypes.html indicate that the
Fortran interface supports only H5T_NATIVE_INTEGER. I remember that someone
hinted at using convert or some other trick to store longer integers but (i) the
list is hard to search for, as there is no search facility and (ii) I am looking
for a standard solution, if possible.
I need to store a variable that is "bind(c)" and of type "c_int64_t", as defined
in the iso_c_binding. This variable cannot be stored in the HDF5 file as the
h5dwrite_f routine is only overloaded to accept "integer" (i.e. the default
kind).
If I am mistaken, I would be glad to know how to overcome the problem.
Else, I would have a more general question: is it planned for HDF5 to support
routinely the iso_c_binding kinds? A priori the overloading could be limited to
the typical c_int8_t, c_int16_t, c_int32_t and c_int64_t (if available on the
platform) and resolved at compile type, even if the user chose to declare the
variables as "integer", "integer(kind=some_other_kind)".
In my situation, I would like to store a PRNG seed and thus need an exact
mapping of the c_int64_t type on disk.
Thanks for any info.
Regards,
Pierre
Hi,
I am developing a Fortran code that uses HDF5. The Fortran API datatypes listed
at https://www.hdfgroup.org/HDF5/doc/RM/PredefDTypes.html indicate that the
Fortran interface supports only H5T_NATIVE_INTEGER. I remember that someone
hinted at using convert or some other trick to store longer integers but (i) the
list is hard to search for, as there is no search facility and (ii) I am looking
for a standard solution, if possible.
I need to store a variable that is "bind(c)" and of type "c_int64_t", as defined
in the iso_c_binding. This variable cannot be stored in the HDF5 file as the
h5dwrite_f routine is only overloaded to accept "integer" (i.e. the default
kind).
If I am mistaken, I would be glad to know how to overcome the problem.
You can read/write any fortran type which has a C representation if you use the F2003 interface for
H5Dread and H5Dwrite.
Take a look at the examples with the _F03 in the name (they use the F2003 interfaces):
https://www.hdfgroup.org/HDF5/examples/api18-fortran.html
But you would also be interested in rwdset_fortran2003.f90 at
https://www.hdfgroup.org/HDF5/examples/f-src.html
Scot
Else, I would have a more general question: is it planned for HDF5 to support
routinely the iso_c_binding kinds? A priori the overloading could be limited to
the typical c_int8_t, c_int16_t, c_int32_t and c_int64_t (if available on the
platform) and resolved at compile type, even if the user chose to declare the
variables as "integer", "integer(kind=some_other_kind)".
In my situation, I would like to store a PRNG seed and thus need an exact
mapping of the c_int64_t type on disk.
Thanks for any info.
Regards,
Pierre
···
On Jan 21, 2016, at 6:55 AM, Pierre de Buyl <pierre.debuyl@chem.kuleuven.be<mailto:pierre.debuyl@chem.kuleuven.be>> wrote:
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Hello,
Thank you very much. This is exactly what I was looking for, except that I was
looking for a directly overloaded Fortran version. This is close enough 
Regards,
Pierre
···
On Thu, Jan 21, 2016 at 03:06:16PM +0000, Scot Breitenfeld wrote:
On Jan 21, 2016, at 6:55 AM, Pierre de Buyl > <pierre.debuyl@chem.kuleuven.be> wrote:
Hi,
I am developing a Fortran code that uses HDF5. The Fortran API
datatypes listed
at https://www.hdfgroup.org/HDF5/doc/RM/PredefDTypes.html indicate that
the
Fortran interface supports only H5T_NATIVE_INTEGER. I remember that
someone
hinted at using convert or some other trick to store longer integers
but (i) the
list is hard to search for, as there is no search facility and (ii) I
am looking
for a standard solution, if possible.
I need to store a variable that is "bind(c)" and of type "c_int64_t",
as defined
in the iso_c_binding. This variable cannot be stored in the HDF5 file
as the
h5dwrite_f routine is only overloaded to accept "integer" (i.e. the
default
kind).
If I am mistaken, I would be glad to know how to overcome the problem.
You can read/write any fortran type which has a C representation if you
use the F2003 interface for
H5Dread and H5Dwrite.
Take a look at the examples with the _F03 in the name (they use the
F2003 interfaces):
https://www.hdfgroup.org/HDF5/examples/api18-fortran.html
But you would also be interested in rwdset_fortran2003.f90 at
https://www.hdfgroup.org/HDF5/examples/f-src.html
Scot
Else, I would have a more general question: is it planned for HDF5 to
support
routinely the iso_c_binding kinds? A priori the overloading could be
limited to
the typical c_int8_t, c_int16_t, c_int32_t and c_int64_t (if available
on the
platform) and resolved at compile type, even if the user chose to
declare the
variables as "integer", "integer(kind=some_other_kind)".
In my situation, I would like to store a PRNG seed and thus need an
exact
mapping of the c_int64_t type on disk.
Thanks for any info.
Regards,
Pierre
