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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
/*!
* \file np_weibull_op.h
* \brief Operator for numpy sampling from weibull distribution.
*/
#ifndef MXNET_OPERATOR_NUMPY_RANDOM_NP_WEIBULL_OP_H_
#define MXNET_OPERATOR_NUMPY_RANDOM_NP_WEIBULL_OP_H_
#include <mxnet/operator_util.h>
#include <algorithm>
#include <string>
#include <vector>
#include <cmath>
#include <unordered_map>
#include "../../elemwise_op_common.h"
#include "../../mshadow_op.h"
#include "../../mxnet_op.h"
#include "../../operator_common.h"
#include "../../tensor/elemwise_binary_broadcast_op.h"
#include "./dist_common.h"
namespace mxnet {
namespace op {
struct NumpyWeibullParam : public dmlc::Parameter<NumpyWeibullParam> {
dmlc::optional<float> a;
dmlc::optional<mxnet::Tuple<index_t>> size;
std::string ctx;
DMLC_DECLARE_PARAMETER(NumpyWeibullParam) {
DMLC_DECLARE_FIELD(a).set_default(dmlc::optional<float>());
DMLC_DECLARE_FIELD(size)
.set_default(dmlc::optional<mxnet::Tuple<index_t>>())
.describe(
"Output shape. If the given shape is, "
"e.g., (m, n, k), then m * n * k samples are drawn. "
"Default is None, in which case a single value is returned.");
DMLC_DECLARE_FIELD(ctx).set_default("cpu").describe(
"Context of output, in format [cpu|gpu|cpu_pinned](n)."
" Only used for imperative calls.");
}
void SetAttrDict(std::unordered_map<std::string, std::string>* dict) {
std::ostringstream a_s, size_s;
a_s << a;
size_s << size;
(*dict)["a"] = a_s.str();
(*dict)["size"] = size_s.str();
}
};
template <typename DType>
struct scalar_weibull_kernel {
MSHADOW_XINLINE static void Map(index_t i, float a, float* noise, DType* out) {
out[i] = powf(-log(noise[i]), DType(1.0 / a));
}
};
namespace mxnet_op {
template <typename IType>
struct check_legal_a_kernel {
MSHADOW_XINLINE static void Map(index_t i, IType* a, float* flag) {
if (a[i] <= 0.0) {
flag[0] = -1.0;
}
}
};
template <int ndim, typename IType, typename OType>
struct weibull_kernel {
MSHADOW_XINLINE static void Map(index_t i,
const Shape<ndim>& stride,
const Shape<ndim>& oshape,
IType* aparams,
float* noise,
OType* out) {
Shape<ndim> coord = unravel(i, oshape);
auto idx = static_cast<index_t>(dot(coord, stride));
noise[i] = -log(noise[i]);
out[i] = powf(noise[i], IType(1.0 / aparams[idx]));
// get grad
noise[i] = -log(noise[i]) * out[i] * (1.0 / (aparams[idx] * aparams[idx]));
}
};
} // namespace mxnet_op
template <typename xpu>
void NumpyWeibullForward(const nnvm::NodeAttrs& attrs,
const OpContext& ctx,
const std::vector<TBlob>& inputs,
const std::vector<OpReqType>& req,
const std::vector<TBlob>& outputs) {
using namespace mshadow;
using namespace mxnet_op;
const NumpyWeibullParam& param = nnvm::get<NumpyWeibullParam>(attrs.parsed);
Stream<xpu>* s = ctx.get_stream<xpu>();
Random<xpu, float>* prnd = ctx.requested[0].get_random<xpu, float>(s);
Tensor<xpu, 1, float> workspace = ctx.requested[1].get_space_typed<xpu, 1, float>(Shape1(1), s);
Tensor<xpu, 1, float> uniform_tensor = outputs[1].FlatTo1D<xpu, float>(s);
Tensor<xpu, 1, float> indicator_device = workspace;
float indicator_host = 1.0;
float* indicator_device_ptr = indicator_device.dptr_;
Kernel<set_zero, xpu>::Launch(s, 1, indicator_device_ptr);
prnd->SampleUniform(&uniform_tensor, 0.0, 1.0);
if (param.a.has_value()) {
CHECK_GT(param.a.value(), 0.0) << "ValueError: expect a > 0";
MSHADOW_REAL_TYPE_SWITCH(outputs[0].type_flag_, DType, {
Kernel<scalar_weibull_kernel<DType>, xpu>::Launch(
s, outputs[0].Size(), param.a.value(), uniform_tensor.dptr_, outputs[0].dptr<DType>());
});
} else {
MSHADOW_TYPE_SWITCH(inputs[0].type_flag_, IType, {
Kernel<check_legal_a_kernel<IType>, xpu>::Launch(
s, inputs[0].Size(), inputs[0].dptr<IType>(), indicator_device_ptr);
});
_copy<xpu>(s, &indicator_host, indicator_device_ptr);
CHECK_GE(indicator_host, 0.0) << "ValueError: expect a > 0";
mxnet::TShape new_lshape, new_oshape;
int ndim = FillShape(inputs[0].shape_,
inputs[0].shape_,
outputs[0].shape_,
&new_lshape,
&new_lshape,
&new_oshape);
MSHADOW_TYPE_SWITCH(inputs[0].type_flag_, IType, {
MSHADOW_REAL_TYPE_SWITCH(outputs[0].type_flag_, OType, {
BROADCAST_NDIM_SWITCH(ndim, NDim, {
Shape<NDim> oshape = new_oshape.get<NDim>();
Shape<NDim> stride = calc_stride(new_lshape.get<NDim>());
Kernel<weibull_kernel<NDim, IType, OType>, xpu>::Launch(s,
outputs[0].Size(),
stride,
oshape,
inputs[0].dptr<IType>(),
uniform_tensor.dptr_,
outputs[0].dptr<OType>());
});
});
});
}
}
template <typename xpu>
void WeibullReparamBackward(const nnvm::NodeAttrs& attrs,
const OpContext& ctx,
const std::vector<TBlob>& inputs,
const std::vector<OpReqType>& reqs,
const std::vector<TBlob>& outputs) {
// skip kernel launch for zero-size tensors
if (inputs[0].shape_.Size() == 0U) {
return;
}
// [scalar] case
if (outputs.size() == 0U) {
return;
}
// [tensor] case
if (inputs.size() == 5U) {
mxnet::TShape new_ishape, new_oshape;
int ndim = FillShape(outputs[0].shape_,
outputs[0].shape_,
inputs[0].shape_,
&new_ishape,
&new_ishape,
&new_oshape);
MSHADOW_REAL_TYPE_SWITCH(outputs[0].type_flag_, DType, {
BROADCAST_NDIM_SWITCH(ndim, NDim, {
CommonScalarReparamBackwardImpl<xpu, NDim, DType>(
ctx, inputs, reqs, outputs, new_ishape, new_oshape);
});
});
}
}
} // namespace op
} // namespace mxnet
#endif // MXNET_OPERATOR_NUMPY_RANDOM_NP_WEIBULL_OP_H_