span></a>] = obj.build(…, ‘file’, <a class="reference internal" href="#statevector-build-inputs-filename"><span class="std std-ref">filename</span></a>)</div>
</div>
</pre><p>Saves the state vector ensemble to a .ens file of the specified name. The saved ensemble can then be accessed at any time using the “ensemble” class. This option allows you to build ensembles that are too large to fit in active memory. When writing the ensemble to file, the first output is an ensemble object, which can be use