\donttest{
tmp <- tempfile(fileext = ".h5")
# Create dataset using BigDataStatMeth API
X <- hdf5_create_matrix(tmp, "data/expression",
data = matrix(rnorm(200), 20, 10))
dim(X) # 20 x 10
X[1:5, 1:3] # subset
crossprod(X) # t(X) %*% X
close(X)
unlink(tmp)
}hdf5_matrix
hdf5_matrix
HDF5MATRIX_CORE
1 Description
Opens an existing dataset in an HDF5 file and returns an HDF5Matrix object that can be used with standard R syntax: dim(), [i,j], \%*\%, crossprod(), and tcrossprod().
2 Usage
hdf5_matrix(filename, path)3 Arguments
| Parameter | Description |
|---|---|
filename |
Path to an existing HDF5 file |
path |
Full path to the dataset within the file, in the form or |
4 Value
An object
5 Details
The HDF5 file remains open while the object exists, which improves performance for repeated operations. Call $close() to release the file lock explicitly, or use rm() and gc() for automatic cleanup. In an emergency, hdf5_close_all closes all open HDF5Matrix objects.