Reading and writing#
HDF5 is a portable format to store arbitrary numerical data, collected in a hierarchical structure of nested subgroups, whose leaves are actual datasets (e.g., arrays, strings, numbers, etc).
This module provides functions to read and write MPS objects
from and to HDF5 files. Each quantum state is stored in a separate group,
with a name supplied by the user. If g is the HDF5 group, the format
consists of the following datasets and attributes:
g[“length”], integer N with the size of the MPS.
g.attrs[“type”] is “MPS”
g.attrs[“version”] is 1 for this library.
g[“MPS[0]”], g[“MPS[1]”] and subsequent fields are datasets for each of the tensors.
SeeMPS uses the Python library h5py to read and write states in these structured files. For instance, the following code creates a file with a single MPS stored in the group “state”. Afterwards, it reads the same state from the file.
import h5py
import seemps
# Create a single file, overwriting any existing one
with h5py.File("data.hdf5", "w") as file:
seemps.hdf5.write_mps(file, "state" my_mps
# Read the MPS from the same file, reopening it as read-only
with h5py.File("data.hdf5", "r") as file
seemps.hdf5.read_mps(file, "state")
This is a summary of all the functions provided by seemps.hdf5.