Run Forward Backward Algorithm in analysis formulation.

[paquiteau]

Currently, only synthesis formulation is supported. But for a tight-frame operator both formulations are equivalent. A solution would be to enrich the proximal operator (e.g.SparseThreshold) as such:

class InTransformSparseThreshold(SparseThreshold):
    """Sparse Thresholding in a transform domain."""

    def _op_method(self, input_data, extra_factor=1.0):
        return self._linear.adj_op(
            super()._op_method(self._linear.op(input_data), extra_factor=extra_factor)
        )