Write data to HDF5 file.
|
Syntax |
Description |
|---|---|
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h5write("filename", "dataset_name", data); |
Writes data to a dataset named "dataset_name" in an HDF5 file named "filename". Will create an HDF5 file named "filename" if it does not exist. Otherwise, the dataset is simply added to the existing HDF5 file. |
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h5write("filename", "dataset_name", data, ["access_mode"]); |
Optional argument: "append" or "overwrite" "append": The dataset is added to an existing HDF5 file. If the file does not exist, it is created. This option is set by default. "overwrite": If the HDF5 file named "filename" already exists, the file is overwritten completely. Otherwise, it will be created. The file will only contain the group named "group_name" and the attribute named "attribute_name". |
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h5write("filename", "dataset_name", data, [{"datatype": "datatype_name"}]); |
Optional argument. This struct indicates the data type in which the data is stored in the HDF5 file. Possible options: {“datatype”: “short”}: data is stored as short integers. {“datatype”: “int”}: data is stored as integers. {“datatype”: “long long”}: data is stored as long long integers. {“datatype”: “double”}: data is stored as doubles. |
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Parameter |
Type |
Description |
|---|---|---|
|
filename |
string |
Name of the HDF5 file |
|
dataset_name |
string |
Name of the dataset |
|
data |
matrix |
Real or complex data. |
|
access_mode |
string |
Optional argument. Only the strings "append" and "overwrite" are valid options. |
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{"datatype": datatype_name} |
struct |
Optional argument. If given, the string “datatype” is a mandatory field in the struct. The field can only have the string values “short”, “int”, “long long”, and “double”. The latter is the default data type. |
Example
Write a real matrix to an HDF5 file as a dataset. Firstly, the matrix is stored using the default data type. Secondly, the matrix is stored as integer dataset.
a = [1, 2, pi; 4, 5, 2*pi];
h5write("testfile.h5", "double_matrix", a);
h5write("testfile.h5", "int_matrix", a, {"datatype":"int"});
Reading the data using h5read gives the following results.
?h5read("testfile.h5", "double_matrix");
result:
1 2 3.14159
4 5 6.28319
?h5read("testfile.h5", "int_matrix");
result:
1 2 3
4 5 6
Overwrite the existing HDF5 file by replacing the existing data with a real 1D matrix as a dataset.
b = [2, 3, 5, 7, 11, 13];
h5write("testfile.h5", "test_vector", b, "overwrite");
Applying h5info and h5read to the HDF5 file shows a singular dataset named "test_vector" which contains the given 1D matrix.
info = h5info("testfile.h5");
?info.Datasets
Cell array with 1 elements
?h5read("testfile.h5", "test_vector");
result:
2 3 5 7 11 13
See Also
List of commands , h5info , h5read , h5readattr , Reading HDF5 files