1 // Tencent is pleased to support the open source community by making ncnn available.
2 //
3 // Copyright (C) 2017 THL A29 Limited, a Tencent company. All rights reserved.
4 //
5 // Licensed under the BSD 3-Clause License (the "License"); you may not use this file except
6 // in compliance with the License. You may obtain a copy of the License at
7 //
8 // https://opensource.org/licenses/BSD-3-Clause
9 //
10 // Unless required by applicable law or agreed to in writing, software distributed
11 // under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
12 // CONDITIONS OF ANY KIND, either express or implied. See the License for the
13 // specific language governing permissions and limitations under the License.
14 
15 #include "log.h"
16 
17 #include <math.h>
18 
19 namespace ncnn {
20 
Log()21 Log::Log()
22 {
23     one_blob_only = true;
24     support_inplace = true;
25 }
26 
load_param(const ParamDict & pd)27 int Log::load_param(const ParamDict& pd)
28 {
29     base = pd.get(0, -1.f);
30     scale = pd.get(1, 1.f);
31     shift = pd.get(2, 0.f);
32 
33     return 0;
34 }
35 
forward_inplace(Mat & bottom_top_blob,const Option & opt) const36 int Log::forward_inplace(Mat& bottom_top_blob, const Option& opt) const
37 {
38     int w = bottom_top_blob.w;
39     int h = bottom_top_blob.h;
40     int channels = bottom_top_blob.c;
41     int size = w * h;
42 
43     if (base == -1.f)
44     {
45         #pragma omp parallel for num_threads(opt.num_threads)
46         for (int q = 0; q < channels; q++)
47         {
48             float* ptr = bottom_top_blob.channel(q);
49 
50             for (int i = 0; i < size; i++)
51             {
52                 ptr[i] = static_cast<float>(log(shift + ptr[i] * scale));
53             }
54         }
55     }
56     else
57     {
58         float log_base_inv = static_cast<float>(1.f / log(base));
59 
60         #pragma omp parallel for num_threads(opt.num_threads)
61         for (int q = 0; q < channels; q++)
62         {
63             float* ptr = bottom_top_blob.channel(q);
64 
65             for (int i = 0; i < size; i++)
66             {
67                 ptr[i] = static_cast<float>(log(shift + ptr[i] * scale) * log_base_inv);
68             }
69         }
70     }
71 
72     return 0;
73 }
74 
75 } // namespace ncnn
76