BigDataStatMeth (version 1.0.3)

bdgetDiagonal_hdf5: Get Matrix Diagonal from HDF5

Description

Retrieves the diagonal elements from a matrix stored in an HDF5 file.

Usage

bdgetDiagonal_hdf5(filename, group, dataset)

Value

Numeric vector containing diagonal elements.

Arguments

filename

Character string. Path to the HDF5 file.

group

Character string. Path to the group containing the dataset.

dataset

Character string. Name of the dataset.

Details

This function provides efficient access to matrix diagonal elements with:

• Access features:

  • Direct diagonal access

  • Memory-efficient retrieval

  • Support for large matrices

• Implementation features:

  • Safe HDF5 file operations

  • Memory-efficient implementation

  • Comprehensive error handling

  • Read-only access to files

The function opens the HDF5 file in read-only mode to ensure data safety.

References

• The HDF Group. (2000-2010). HDF5 User's Guide.

See Also

• bdWriteDiagonal_hdf5 for writing diagonal elements

• bdCreate_hdf5_matrix for creating HDF5 matrices

Examples

if (FALSE) {
library(BigDataStatMeth)

# Create test matrix
X <- matrix(rnorm(100), 10, 10)
diag(X) <- 0.5

# Save to HDF5
bdCreate_hdf5_matrix("test.hdf5", X, "data", "matrix1",
                     overwriteFile = TRUE)

# Get diagonal
diag_elements <- bdgetDiagonal_hdf5("test.hdf5", "data", "matrix1")
print(diag_elements)

# Cleanup
if (file.exists("test.hdf5")) {
  file.remove("test.hdf5")
}
}