From 1c1f73b46dd83013a382498f64888dc426ef13ee Mon Sep 17 00:00:00 2001 From: Yan Chunwei Date: Fri, 13 Oct 2017 00:18:10 -0400 Subject: [PATCH] Feature/dynamic recurrent op forward test (#4729) --- paddle/framework/tensor_array.cc | 28 +-- paddle/framework/tensor_array.h | 12 +- paddle/operators/dynamic_recurrent_op.cc | 162 ++++++++++++------ paddle/operators/dynamic_recurrent_op.h | 26 ++- paddle/operators/dynamic_recurrent_op_test.cc | 1 - paddle/operators/sum_op.cc | 2 +- paddle/pybind/pybind.cc | 28 +++ python/paddle/v2/framework/op.py | 22 +++ .../tests/test_dynamic_recurrent_op.py | 111 ++++++++++++ 9 files changed, 323 insertions(+), 69 deletions(-) create mode 100644 python/paddle/v2/framework/tests/test_dynamic_recurrent_op.py diff --git a/paddle/framework/tensor_array.cc b/paddle/framework/tensor_array.cc index 7ae16e99c..06459cbfd 100644 --- a/paddle/framework/tensor_array.cc +++ b/paddle/framework/tensor_array.cc @@ -76,6 +76,17 @@ LoDTensor PackDynamicBatch(const std::vector& source, const std::vector& meta, const LoD& lod, size_t level); +std::vector GenDyBatchIndice(const DySeqMetaBatch& meta, int batch_id) { + // collect indice need to copy to the batch + std::vector indice; + for (const auto& seq : meta) { + size_t id = seq.begin + batch_id; + if (id >= seq.end) break; + indice.push_back(id); + } + return indice; +} + } // namespace detail const LoDTensor& TensorArray::Read(size_t index) const { @@ -113,8 +124,8 @@ LoDTensor TensorArray::Pack(size_t level, const std::vector& meta, return detail::PackDynamicBatch(values_, meta, lod, level); } -std::vector TensorArray::Unpack(const LoDTensor& source, int level, - bool length_desend) { +DySeqMetaBatch TensorArray::Unpack(const LoDTensor& source, int level, + bool length_desend) { detail::DynamicBatchUnpacker unpacker(source, level, length_desend /*descend*/); @@ -129,6 +140,7 @@ std::vector TensorArray::Unpack(const LoDTensor& source, int level, Write(batch_id, unpacker.GetBatch(batch_id)); } + PADDLE_ENFORCE(!unpacker.meta.empty()); return unpacker.meta; } @@ -218,13 +230,7 @@ LoDTensor DynamicBatchUnpacker::GetBatch(size_t index) { PADDLE_ENFORCE(!meta.empty(), "should build meta first"); LoDTensor result; - // collect indice need to copy to the batch - std::vector indice; - for (const auto& seq : meta) { - size_t id = seq.begin + index; - if (id >= seq.end) break; - indice.push_back(id); - } + auto indice = detail::GenDyBatchIndice(meta, index); PADDLE_ENFORCE(!indice.empty(), "invalid batch at %d", index); // copy the indice of records in LoDTensor @@ -237,9 +243,9 @@ LoDTensor DynamicBatchUnpacker::GetBatch(size_t index) { for (size_t i = 0; i < indice.size(); i++) { auto index = indice[i]; auto target = result.Slice(i, i + 1); - auto source_ = source->Slice(index, index + 1); + auto slice = source->Slice(index, index + 1); - target.CopyFrom(source_, platform::CPUPlace(), + target.CopyFrom(slice, platform::CPUPlace(), platform::CPUDeviceContext()); } diff --git a/paddle/framework/tensor_array.h b/paddle/framework/tensor_array.h index 293da0499..046ecb522 100644 --- a/paddle/framework/tensor_array.h +++ b/paddle/framework/tensor_array.h @@ -34,6 +34,13 @@ struct DySeqMeta { size_t ori_idx; }; +using DySeqMetaBatch = std::vector; + +/* + * Extract the indices of instances. + */ +std::vector GenDyBatchIndice(const DySeqMetaBatch &metas, int batch_id); + /* * TensorArray is a C-array-like array of tensors, it is meant to be used with * dynamic iteration primitives such as while_loop. It is used to segment inputs @@ -69,7 +76,7 @@ class TensorArray { * Recover the original LoD-arranged LoDTensor with the `values`, `level` and * `indice_map`. */ - LoDTensor Pack(size_t level, const std::vector &meta, + LoDTensor Pack(size_t level, const DySeqMetaBatch &meta, const LoD &lod) const; /* @@ -77,8 +84,7 @@ class TensorArray { * `values`, if set `desend`, will sort by length in descending order else in * ascending order. */ - std::vector Unpack(const LoDTensor &source, int level, - bool length_desend); + DySeqMetaBatch Unpack(const LoDTensor &source, int level, bool length_desend); /* * Pack the values into a tensor with rank one higher than each tensor in diff --git a/paddle/operators/dynamic_recurrent_op.cc b/paddle/operators/dynamic_recurrent_op.cc index b919aef8f..58a5bf3e3 100644 --- a/paddle/operators/dynamic_recurrent_op.cc +++ b/paddle/operators/dynamic_recurrent_op.cc @@ -23,6 +23,7 @@ using framework::Scope; using framework::TensorArray; using framework::LoDTensor; using framework::Variable; +using framework::DySeqMetaBatch; namespace detail { @@ -33,6 +34,29 @@ inline void CreateVariables(Scope& scope, } } +/* + * The inputs with sequence should be reordered when they are split, so the + * boot_states should be reordered in the same order. + * + * NOTE This may require that the `pre_state` of the first time step should just + * copy the `boot_state` rather than reference it, for that the content should + * be reordered, but the RNN op should not change the `boot_state` as an input + * variable's content. + */ +template +inline void ReorderBootState(const DySeqMetaBatch& metas, + const LoDTensor& boot_state, LoDTensor* tensor, + const platform::Place& dst_place) { + for (size_t seq_id = 0; seq_id < metas.size(); seq_id++) { + auto slice = tensor->Slice(seq_id, seq_id + 1); + auto boot_slice = + boot_state.Slice(metas[seq_id].ori_idx, metas[seq_id].ori_idx + 1); + // TODO(superjom) pass in device context as an argument + slice.template CopyFrom(boot_slice, dst_place, + platform::CPUDeviceContext()); + } +} + } // namespace detail class DynamicRecurrentOpProtoAndCheckerMaker @@ -69,6 +93,7 @@ void DynamicRecurrentOp::Run(const Scope& scope, CreateScopes(); WriteStepInputs(); InitStates(); + WriteStepOutputs(); // call stepnet in all the time steps for (size_t step = 0; step < cache_.num_steps; step++) { @@ -76,7 +101,6 @@ void DynamicRecurrentOp::Run(const Scope& scope, stepnet_->Run(step_scope, dev_ctx); } - WriteStepOutputs(); ConcatOutputs(); } @@ -84,11 +108,11 @@ void DynamicRecurrentOp::SplitInputs() const { // TODO(superjom) make level a config // TODO(superjom) check all the inputs has the same LoD int level = 0; - const auto& inlinks = cache_.inlinks; - for (const auto& item : inlinks) { + for (const auto& item : cache_.inlinks) { const auto& var = item.second; const auto& tensor = var->Get(); TensorArray& ta = step_inputs_[item.first]; + dy_seq_metas_[item.first] = ta.Unpack(tensor, level, true /*length_descend*/); @@ -120,17 +144,11 @@ void DynamicRecurrentOp::WriteStepInputs() const { } void DynamicRecurrentOp::WriteStepOutputs() const { - for (size_t step = 0; step < cache_.scopes->size(); step++) { - auto& scope = cache_.GetScope(step); - for (auto& item : step_outputs_) { - auto* var = scope.FindVar(item.first); - if (var == nullptr) { - var = scope.NewVar(item.first); - } - auto* tensor = var->GetMutable(); - item.second.WriteShared(step, *tensor); - } + // initialize step outputs + for (const auto& item : cache_.outlinks) { + step_outputs_.emplace(item.first, TensorArray()); } + PADDLE_ENFORCE_GT(step_outputs_.size(), 0UL); } void DynamicRecurrentOp::CreateScopes() const { @@ -145,12 +163,18 @@ void DynamicRecurrentOp::CreateScopes() const { PADDLE_ENFORCE_NOT_NULL(stepnet_, "stepnet should be set first"); std::vector memories; std::vector pre_memories; + std::vector stepnet_outputs; std::transform(arg_.memories.begin(), arg_.memories.end(), std::back_inserter(memories), [](const rnn::MemoryAttr& m) { return m.var; }); std::transform(arg_.memories.begin(), arg_.memories.end(), std::back_inserter(pre_memories), [](const rnn::MemoryAttr& m) { return m.pre_var; }); + for (const auto& item : stepnet_->Outputs()) { + for (const auto& var : item.second) { + stepnet_outputs.push_back(var); + } + } for (size_t step = 0; step < cache_.num_steps; step++) { auto& scope = cache_.GetScope(step); @@ -158,60 +182,88 @@ void DynamicRecurrentOp::CreateScopes() const { detail::CreateVariables(scope, arg_.outlinks); detail::CreateVariables(scope, memories); detail::CreateVariables(scope, pre_memories); + detail::CreateVariables(scope, stepnet_outputs); } } void DynamicRecurrentOp::ConcatOutputs() const { // TODO(superjom) transform this to a config int level = 0; - // TODO(superjom) pass in some lod - // just a placeholder - framework::LoD lod; + for (size_t step = 0; step < cache_.num_steps; step++) { + auto& scope = cache_.GetScope(step); + for (auto& item : step_outputs_) { + auto* var = scope.FindVar(item.first); + PADDLE_ENFORCE_NOT_NULL(var); + auto* tensor = var->GetMutable(); + tensor->mutable_data(platform::CPUPlace()); + item.second.WriteShared(step, *tensor); + } + } + // the inlinks' lods should be the same, so randomly get one lod. + const auto& some_lod = + cache_.scope->FindVar(arg_.inlinks.front())->Get().lod(); + const auto& some_meta = dy_seq_metas_[arg_.inlinks.front()]; for (auto& item : step_outputs_) { - auto tensor = item.second.Pack(level, dy_seq_metas_[item.first], lod); - auto& output = cache_.outlinks[item.first]->Get(); - const_cast(&output)->ShareDataWith(tensor); + auto tensor = item.second.Pack(level, some_meta, some_lod); + auto* output = cache_.outlinks[item.first]->GetMutable(); + const_cast(output)->ShareDataWith(tensor); } } void DynamicRecurrentOp::InitStates() const { - // init the first state - // TODO(superjom) parepare the scenerio that boot state not exists - for (auto memory : arg_.memories) { - auto* boot_state_var = cache_.scope->FindVar(memory.boot_var); - PADDLE_ENFORCE_NOT_NULL(boot_state_var); - auto& boot_state = boot_state_var->Get(); - const auto& dims = boot_state.dims(); - - for (size_t step = 0; step < cache_.num_steps; step++) { - auto& cur_scope = cache_.GetScope(step); - // link pre-state to boot_state - // init state and pre-state - auto* pre_state = cur_scope.FindVar(memory.pre_var); - PADDLE_ENFORCE_NOT_NULL(pre_state); - pre_state->GetMutable(); - - auto* state = cur_scope.FindVar(memory.var); - PADDLE_ENFORCE_NOT_NULL(state); - state->GetMutable()->Resize(dims); - state->GetMutable()->mutable_data( - platform::CPUPlace()); - - if (step == 0) { - auto* pre_state_tensor = pre_state->GetMutable(); - pre_state_tensor->Resize(boot_state.dims()); - pre_state_tensor->ShareDataWith(boot_state); - } else { - auto& pre_scope = cache_.GetScope(step - 1); - auto* state_pre = pre_scope.FindVar(memory.var); - PADDLE_ENFORCE_NOT_NULL(state_pre); - pre_state->GetMutable()->ShareDataWith( - *state_pre->GetMutable()); - } + for (size_t step = 0; step < cache_.num_steps; step++) { + for (const auto& memory : arg_.memories) { + CreateState(memory, step); + LinkState(memory, step); } } } +void DynamicRecurrentOp::CreateState(const rnn::MemoryAttr& memory, + size_t step) const { + auto& scope = cache_.GetScope(step); + auto& state = *cache_.GetTensor(scope, memory.var); + auto& boot_state = *cache_.GetTensor(*cache_.scope, memory.boot_var); + + size_t num_instances = + step_inputs_[arg_.inlinks.front()].Read(step).dims()[0]; + auto dims = boot_state.dims(); + dims[0] = num_instances; + + state.Resize(dims); + state.mutable_data(platform::CPUPlace()); + states_[memory.var].WriteShared(step, state); +} + +void DynamicRecurrentOp::LinkState(const rnn::MemoryAttr& memory, + size_t step) const { + auto& scope = cache_.GetScope(step); + auto& state_pre = *cache_.GetTensor(scope, memory.pre_var); + + // all the step_inputs' metas should be the same, just randomly select one + // and get the dyseq meta. + const auto& some_meta = dy_seq_metas_[arg_.inlinks.front()]; + size_t num_instances = + step_inputs_[arg_.inlinks.front()].Read(step).dims()[0]; + + LoDTensor* pre_state{nullptr}; + if (step == 0) { + pre_state = cache_.GetTensor(*cache_.scope, memory.boot_var); + pre_state->mutable_data(platform::CPUPlace()); + // allocate memory + state_pre.Resize(pre_state->dims()); + state_pre.mutable_data(platform::CPUPlace()); + detail::ReorderBootState(some_meta, *pre_state, &state_pre, + pre_state->place()); + } else { + pre_state = cache_.GetTensor(cache_.GetScope(step - 1), memory.var); + } + + // shink and share from previous state + auto shrinked_pre_state = pre_state->Slice(0, num_instances); + state_pre.ShareDataWith(shrinked_pre_state); +} + void DynamicRecurrentOp::ArgCache::Init( const rnn::ArgumentName& name, const paddle::framework::OperatorBase& op, const paddle::framework::Scope& scope, rnn::Argument* arg) { @@ -261,6 +313,12 @@ Variable* DynamicRecurrentOp::ArgCache::GetVariable(const Scope& scope, return var; } +LoDTensor* DynamicRecurrentOp::ArgCache::GetTensor( + const framework::Scope& scope, const std::string& name) { + auto* var = GetVariable(scope, name); + return var->GetMutable(); +} + const rnn::ArgumentName DynamicRecurrentOp::kArgName{ "step_net", "step_scopes", "inlinks", "outlinks", "memories", "pre_memories", "boot_memories"}; diff --git a/paddle/operators/dynamic_recurrent_op.h b/paddle/operators/dynamic_recurrent_op.h index 6a2970f27..ec80a1c90 100644 --- a/paddle/operators/dynamic_recurrent_op.h +++ b/paddle/operators/dynamic_recurrent_op.h @@ -77,6 +77,17 @@ class DynamicRecurrentOp : public framework::OperatorBase { */ void InitStates() const; + /* + * Create state variables for each time step. + */ + void CreateState(const rnn::MemoryAttr& memory, size_t step) const; + + /* + * Link pre-state variable in current scope to the state variable in the + * previous time step (scope). + */ + void LinkState(const rnn::MemoryAttr& memory, size_t step) const; + /* * Concatenate outputs in each time step and generate a LoDTensor. */ @@ -91,6 +102,16 @@ class DynamicRecurrentOp : public framework::OperatorBase { } const OperatorBase& GetStepNet() const { return *stepnet_; } + const framework::TensorArray& state(const std::string& name) const { + return states_[name]; + } + const framework::TensorArray& step_input(const std::string& name) const { + return step_inputs_[name]; + } + const framework::TensorArray& step_output(const std::string& name) const { + return step_outputs_[name]; + } + protected: struct ArgCache { framework::Scope const* scope; @@ -108,6 +129,9 @@ class DynamicRecurrentOp : public framework::OperatorBase { return *scopes->at(index); } + framework::LoDTensor* GetTensor(const framework::Scope& scope, + const std::string& name); + private: void InitArgument(const rnn::ArgumentName& name, const OperatorBase& op, rnn::Argument* arg); @@ -122,7 +146,7 @@ class DynamicRecurrentOp : public framework::OperatorBase { private: std::unique_ptr stepnet_; - mutable framework::TensorArray states_; + mutable std::map states_; mutable std::map step_inputs_; mutable std::map step_outputs_; mutable std::map> diff --git a/paddle/operators/dynamic_recurrent_op_test.cc b/paddle/operators/dynamic_recurrent_op_test.cc index 675a7890f..b849c4541 100644 --- a/paddle/operators/dynamic_recurrent_op_test.cc +++ b/paddle/operators/dynamic_recurrent_op_test.cc @@ -87,7 +87,6 @@ class DynamicRecurrentOpTestHelper : public ::testing::Test { platform::CPUPlace place; scope.NewVar("step_scopes"); CreateVar(scope, "boot_mem", framework::make_ddim({10, 20}), place); - // auto* out0 = CreateVar(scope, "out0", framework::make_ddim({10, 20}), place); auto* in0 = CreateVar(scope, "in0", framework::make_ddim({10, 8}), place); // 10 instanes with 4 sentences, length is 4, 3, 2, 1 respectively. diff --git a/paddle/operators/sum_op.cc b/paddle/operators/sum_op.cc index ffb0cb921..573487b83 100644 --- a/paddle/operators/sum_op.cc +++ b/paddle/operators/sum_op.cc @@ -34,7 +34,7 @@ class SumOp : public framework::OperatorWithKernel { auto in_dim = x_dims[0]; for (size_t i = 1; i < N; i++) { auto dim = x_dims[i]; - PADDLE_ENFORCE(in_dim == dim, "Input tensors must have same shape"); + PADDLE_ENFORCE_EQ(in_dim, dim, "Input tensors must have same shape"); } ctx->SetOutputDim("Out", in_dim); ctx->ShareLoD("X", /*->*/ "Out"); diff --git a/paddle/pybind/pybind.cc b/paddle/pybind/pybind.cc index 0f6e3101e..cc9f7ffe0 100644 --- a/paddle/pybind/pybind.cc +++ b/paddle/pybind/pybind.cc @@ -18,6 +18,7 @@ limitations under the License. */ #include "paddle/framework/lod_tensor.h" #include "paddle/framework/tensor_array.h" #include "paddle/operators/cond_op.h" +#include "paddle/operators/dynamic_recurrent_op.h" #include "paddle/operators/net_op.h" #include "paddle/operators/recurrent_op.h" #include "paddle/platform/enforce.h" @@ -341,6 +342,33 @@ All parameter, weight, gradient are variables in Paddle. self.set_stepnet(net.Clone()); }); + py::class_(m, + "DynamicRecurrentOp") + .def_static("create", + [](py::bytes protobin) -> operators::DynamicRecurrentOp * { + OpDesc desc; + PADDLE_ENFORCE(desc.ParsePartialFromString(protobin), + "Cannot parse user input to OpDesc"); + PADDLE_ENFORCE(desc.IsInitialized(), + "User OpDesc is not initialized, reason %s", + desc.InitializationErrorString()); + auto rnn_op = OpRegistry::CreateOp(desc); + return static_cast( + rnn_op.release()); + }) + .def("set_stepnet", + [](operators::DynamicRecurrentOp &self, const operators::NetOp &net) + -> void { self.SetStepNet(net.Clone()); }) + .def("get_state", + [](operators::DynamicRecurrentOp &self, const std::string &name) + -> const TensorArray & { return self.state(name); }) + .def("get_step_input", + [](operators::DynamicRecurrentOp &self, const std::string &name) + -> const TensorArray & { return self.step_input(name); }) + .def("get_step_output", + [](operators::DynamicRecurrentOp &self, const std::string &name) + -> const TensorArray & { return self.step_output(name); }); + // cond_op py::class_(m, "CondOp") .def_static("create", diff --git a/python/paddle/v2/framework/op.py b/python/paddle/v2/framework/op.py index 9086a5cc3..bc771a964 100644 --- a/python/paddle/v2/framework/op.py +++ b/python/paddle/v2/framework/op.py @@ -219,6 +219,27 @@ class __RecurrentOp__(object): return core.RecurrentOp.create(proto.SerializeToString()) +class __DynamicRecurrentOp__(object): + __proto__ = None + type = "dynamic_recurrent" + + def __init__(self): + # cache recurrent_op's proto + if self.__proto__ is None: + for op_proto in get_all_op_protos(): + if op_proto.type == self.type: + self.__proto__ = op_proto + + def __call__(self, *args, **kwargs): + if self.type not in args and "type" not in kwargs: + kwargs["type"] = self.type + # create proto + create_method = OpDescCreationMethod(self.__proto__) + proto = create_method(*args, **kwargs) + # create rnnop + return core.DynamicRecurrentOp.create(proto.SerializeToString()) + + class __CondOp__(object): __proto__ = None type = "cond" @@ -242,4 +263,5 @@ class __CondOp__(object): Operator = OperatorFactory() # The default global factory RecurrentOp = __RecurrentOp__() +DynamicRecurrentOp = __DynamicRecurrentOp__() CondOp = __CondOp__() diff --git a/python/paddle/v2/framework/tests/test_dynamic_recurrent_op.py b/python/paddle/v2/framework/tests/test_dynamic_recurrent_op.py new file mode 100644 index 000000000..b4629a3ad --- /dev/null +++ b/python/paddle/v2/framework/tests/test_dynamic_recurrent_op.py @@ -0,0 +1,111 @@ +import logging +import paddle.v2.framework.core as core +import unittest +from paddle.v2.framework.op import Operator, DynamicRecurrentOp +import numpy as np + + +def create_tensor(scope, name, shape, np_data): + tensor = scope.new_var(name).get_tensor() + tensor.set_dims(shape) + tensor.set(np_data, core.CPUPlace()) + return tensor + + +class DynamicRecurrentOpTest(unittest.TestCase): + ''' + Test RNNOp + + equation: + h_t = \sigma (W x_t + U h_{t-1}) + weights: + - W + - U + vars: + - x + memories: + - h + outputs: + - h + ''' + + # for siplicity, just one level LoD + lod_py = [[0, 4, 7, 9, 10]] + input_dim = 30 + num_sents = len(lod_py[0]) - 1 + weight_dim = 15 + + def forward(self): + self.scope = core.Scope() + self.create_global_variables() + self.create_rnn_op() + self.create_step_net() + ctx = core.DeviceContext.create(core.CPUPlace()) + self.rnnop.run(self.scope, ctx) + state = self.rnnop.get_state("h@mem") + print 'state size: ', state.size() + + step_inputs = self.rnnop.get_step_input("x") + print "x size ", step_inputs.size() + for i in range(step_inputs.size()): + print "x %d" % i, np.array(step_inputs.read(i).get_dims()) + step_outputs = self.rnnop.get_step_output('h@mem') + print 'step_outputs.size ', step_outputs.size() + output = self.scope.find_var("h@mem").get_tensor() + + print 'output', np.array(output).shape + + def create_global_variables(self): + x = np.random.normal(size=(self.lod_py[0][-1], + self.input_dim)).astype("float32") + W = np.random.normal(size=(self.input_dim, + self.input_dim)).astype("float32") + U = np.random.normal(size=(self.input_dim, + self.input_dim)).astype("float32") + h_boot = np.random.normal(size=(self.num_sents, + self.input_dim)).astype("float32") + # create inlink + x_tensor = create_tensor(self.scope, "x", + [self.num_sents, self.input_dim], x) + x_tensor.set_lod(self.lod_py) + create_tensor(self.scope, "W", [self.input_dim, self.input_dim], W) + create_tensor(self.scope, "U", [self.input_dim, self.input_dim], U) + create_tensor(self.scope, "h_boot", [self.num_sents, self.input_dim], + h_boot) + self.scope.new_var("step_scopes") + self.scope.new_var("h@mem") + + def create_rnn_op(self): + # create RNNOp + self.rnnop = DynamicRecurrentOp( + # inputs + inlinks=["x"], + boot_memories=["h_boot"], + step_net="stepnet", + # outputs + outlinks=["h@mem"], + step_scopes="step_scopes", + # attributes + pre_memories=["h@pre"], + memories=["h@mem"]) + + def create_step_net(self): + stepnet = core.Net.create() + x_fc_op = Operator("mul", X="x", Y="W", Out="Wx") + h_fc_op = Operator("mul", X="h@pre", Y="U", Out="Uh") + sum_op = Operator("sum", X=["Wx", "Uh"], Out="sum") + sig_op = Operator("sigmoid", X="sum", Y="h@mem") + + for op in [x_fc_op, h_fc_op, sum_op, sig_op]: + stepnet.append_op(op) + stepnet.complete_add_op(True) + self.rnnop.set_stepnet(stepnet) + + def test_forward(self): + print 'test recurrent op forward' + pd_output = self.forward() + print 'pd_output', pd_output + + +if __name__ == '__main__': + unittest.main() -- GitLab