Hi Nathan,
I copied your code below to try and didn't get error. The dataset was
created and written. One difference is, because I didn't have your
function_that_returns_name[value]()s, I defined mine as below:
std::string dataset_name("my dataset");
std::string dataset_value("this dataset has one string");
Binh-Minh
_____
From: Hdf-forum [mailto:[email protected]] On Behalf Of Nathan
Smith
Sent: Tuesday, December 11, 2012 6:07 PM
To: HDF Users Discussion List
Subject: Re: [Hdf-forum] HDF5 string dataset compression
Hi all,
Thanks for your suggestions. I'm still missing something, though. Using
the h5group.cpp example, I can get my code to create a chunked dataset, but
I can't write anything to it.
std::string dataset_name = function_that_returns_name();
std::string dataset_value = function_that_returns_value();
// Is the size the size of the buffer, or the length of the
string? (should I include the null-terminator?)
hsize_t dataset_length = dataset_value.length() + 1;
StrType datatype(0, dataset_length);
hsize_t sdims[1];
sdims[0] = dataset_length;
DataSpace dataspace(1, sdims);
DSetCreatPropList plist;
hsize_t chunk_dims[1];
chunk_dims[0] = 24;
plist.setChunk(1, chunk_dims);
DataSet sim_details = group.createDataSet(dataset_name,
datatype, dataspace, plist);
// This raises a bad pointer exception.
sim_details.write(dataset_value, datatype);
#009: H5FDsec2.c line 846 in H5FD_sec2_write(): file write failed: time =
Tue Dec 11 16:59:46 2012
, filename = 'test.h5', file descriptor = 3, errno = 14, error message =
'Bad address', buf = 0x7f9be0b5a1f8, size = 4115328, offset = 184320
major: Low-level I/O
minor: Write failed
terminate called after throwing an instance of 'H5::DataSetIException'
Nathan
On Tue, Dec 11, 2012 at 4:26 PM, Peter Cao <[email protected]> wrote:
for fixed langth, just replace the H5T_VARIABLE with the length you want to
set.
On 12/11/2012 12:32 PM, Nathan Smith wrote:
I know the length of the string a priori. Can you point me to an example of
writing out a fixed length string that uses compression?
Thanks!
Nathan
On Tue, Dec 11, 2012 at 12:29 PM, Dana Robinson <[email protected]>
wrote:
Hi Nathan,
On Tue, Dec 11, 2012 at 11:20 AM, Nathan Smith <[email protected]>
wrote:
Hi all,
I'm very new to HDF5 and am trying to find an example of how to compress a
string written to an HDF5 file. I've been using the C++ API and writing
scalar strings to my dataset, but I can't figure out how to use data
chunking so that I can enable compression.
Variable-length data cannot be compressed due to the way we store it in the
HDF5 library.
Dana
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_______________________________________________
Hdf-forum is for HDF software users discussion.
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http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org
_______________________________________________
Hdf-forum is for HDF software users discussion.
[email protected]
http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org
_______________________________________________
Hdf-forum is for HDF software users discussion.
[email protected]
http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org
