ó àÆ÷Xc@`s¦dZddlmZmZmZdZdZdZdZddl m Z ddl m Z dd l mZdd lmZmZmZmZdd lmZmZd S( s‡ This module provides the Scan Op. Scanning is a general form of recurrence, which can be used for looping. The idea is that you *scan* a function along some input sequence, producing an output at each time-step that can be seen (but not modified) by the function at the next time-step. (Technically, the function can see the previous K time-steps of your outputs and L time steps (from the past and future) of your inputs. So for example, ``sum()`` could be computed by scanning the ``z+x_i`` function over a list, given an initial state of ``z=0``. Special cases: * A *reduce* operation can be performed by returning only the last output of a ``scan``. * A *map* operation can be performed by applying a function that ignores previous steps of the outputs. Often a for-loop can be expressed as a ``scan()`` operation, and ``scan`` is the closest that theano comes to looping. The advantage of using ``scan`` over for loops is that it allows the number of iterations to be a part of the symbolic graph. The Scan Op should typically be used by calling any of the following functions: ``scan()``, ``map()``, ``reduce()``, ``foldl()``, ``foldr()``. i(tabsolute_importtprint_functiontdivisionsrestructedtext ensNRazvan Pascanu Frederic Bastien James Bergstra Pascal Lamblin Arnaud Bergeron s (c) 2010, Universite de Montreals Razvan Pascanu (tscan_opt(tscan(tscan_checkpoints(tmaptreducetfoldltfoldr(tclonetuntilN(t__doc__t __future__RRRt __docformat__t __authors__t __copyright__t __contact__ttheano.scan_moduleRttheano.scan_module.scanRt#theano.scan_module.scan_checkpointsRttheano.scan_module.scan_viewsRRRR ttheano.scan_module.scan_utilsR R (((s;/tmp/pip-build-X4mzal/theano/theano/scan_module/__init__.pyts"