618c1cac7908e5aa61fd95e0d1c6c1f31a2db95d,pymanopt/core/problem.py,Problem,backend,#Problem#,75

Before Change

    @property
    def backend(self):
        if self._backend is None:
            backend_theano = TheanoBackend()
            backend_autograd = AutogradBackend()
            if backend_theano.is_available():
                if backend_theano.is_compatible(self._original_cost,
                                                self._arg):
                    self._backend = backend_theano
            if backend_autograd.is_available():
                if backend_autograd.is_compatible(self._original_cost,
                                                  self._arg):
                    self._backend = backend_autograd
            if self._backend is None:
                raise ValueError(
                    "Cannot identify an autodiff backend from cost "
                    "function that also was successfully imported. "
                    "TheanoBackend was%s successfully imported. " %
                    ("" if backend_theano.is_available() else " not") +
                    "AutogradBackend was%s successfully imported. " %
                    ("" if backend_autograd.is_available() else " not")
                    )

After Change

    @property
    def backend(self):
        if self._backend is None:
            for backend in self._backends:
                if backend.is_compatible(self._original_cost, self._arg):
                    self._backend = backend
                    break
            else:
                backend_names = [backend.name for backend in self._backends]
                raise ValueError(
                    "Cannot determine autodiff backend from cost function. "
                    "Available backends are: {:s}".format(
                        ", ".join(backend_names)))
        return self._backend

    @property
    def cost(self):

Instances