4.5.3 pde.storage.memory module

Defines a class storing data in memory.

class MemoryStorage(times=None, data=None, *, info=None, field_obj=None, write_mode='truncate_once')[source]

Bases: StorageBase

store discretized fields in memory

Parameters:

times (ndarray) – Sequence of times for which data is known
data (list of ndarray) – The field data at the given times
field_obj (FieldBase) – An instance of the field class store data for a single time point.
info (dict) – Supplies extra information that is stored in the storage
write_mode (str) – Determines how new data is added to already existing data. Possible values are: ‘append’ (data is always appended), ‘truncate’ (data is cleared every time this storage is used for writing), or ‘truncate_once’ (data is cleared for the first writing, but appended subsequently). Alternatively, specifying ‘readonly’ will disable writing completely.

clear(clear_data_shape=False)[source]

truncate the storage by removing all stored data.

Parameters:: clear_data_shape (bool) – Flag determining whether the data shape is also deleted.
Return type:: None

classmethod from_collection(storages, label=None, *, rtol=1e-05, atol=1e-08)[source]

combine multiple memory storages into one

This method can be used to combine multiple time series of different fields into a single representation. This requires that all time series contain data at the same time points.

Parameters:

storages (list) – A collection of instances of StorageBase whose data will be concatenated into a single MemoryStorage
label (str, optional) – The label of the instances of FieldCollection that represent the concatenated data
rtol (float) – Relative tolerance used when checking times for merging
atol (float) – Absolute tolerance used when checking times for merging

Returns:

Storage containing all the data.

Return type:

MemoryStorage

classmethod from_fields(times=None, fields=None, info=None, write_mode='truncate_once')[source]

create MemoryStorage from a list of fields

Parameters:

times (ndarray) – Sequence of times for which data is known
fields (list of FieldBase) – The fields at all given time points
info (dict) – Supplies extra information that is stored in the storage
write_mode (str) – Determines how new data is added to already existing data. Possible values are: ‘append’ (data is always appended), ‘truncate’ (data is cleared every time this storage is used for writing), or ‘truncate_once’ (data is cleared for the first writing, but appended subsequently). Alternatively, specifying ‘readonly’ will disable writing completely.

Return type:

MemoryStorage

start_writing(field, info=None)[source]

initialize the storage for writing data

Parameters:

field (FieldBase) – An instance of the field class store data for a single time point.
info (dict) – Supplies extra information that is stored in the storage

Return type:

None

get_memory_storage(field, info=None)[source]

a context manager that can be used to create a MemoryStorage

Example

This can be used to quickly store data:

with get_memory_storage(field_class) as storage:
    storage.append(numpy_array0, 0)
    storage.append(numpy_array1, 1)

# use storage thereafter

Parameters:

field (FieldBase) – An instance of the field class store data for a single time point.
info (dict) – Supplies extra information that is stored in the storage

Yields:

MemoryStorage