src/rbf.c

   1 #include "a/rbf.h"
   2 #include "a/math.h"
   3
   4 a_float const *a_rbf_iter(a_rbf const *ctx)
   5 {
   6     a_size const input_hidden_n = ctx->input_n * ctx->hidden_n;
   7     for (a_size hidden_i = 0; hidden_i != ctx->hidden_n; ++hidden_i)
   8     {
   9         a_float num = 0;
  10         if (ctx->center_n == input_hidden_n)
  11         {
  12             a_float const *center_p = ctx->center_p + hidden_i;
  13             for (a_size input_i = 0; input_i != ctx->input_n; ++input_i, center_p += ctx->input_n)
  14             {
  15                 a_float const r = ctx->input_p[input_i] - *center_p;
  16                 num += r * r;
  17             }
  18         }
  19         else if (ctx->center_n == ctx->hidden_n)
  20         {
  21             for (a_size input_i = 0; input_i != ctx->input_n; ++input_i)
  22             {
  23                 a_float const r = ctx->input_p[input_i] - ctx->center_p[hidden_i];
  24                 num += r * r;
  25             }
  26         }
  27         else if (ctx->center_n == 1)
  28         {
  29             for (a_size input_i = 0; input_i != ctx->input_n; ++input_i)
  30             {
  31                 a_float const r = ctx->input_p[input_i] - *ctx->center_p;
  32                 num += r * r;
  33             }
  34         }
  35         a_float den = 1;
  36         if (ctx->height_n == ctx->hidden_n)
  37         {
  38             den = ctx->height_p[hidden_i] * ctx->height_p[hidden_i];
  39         }
  40         else if (ctx->height_n == 1)
  41         {
  42             den = *ctx->height_p * *ctx->height_p;
  43         }
  44         ctx->hidden_p[hidden_i] = a_float_exp(-num / den);
  45     }
  46     a_float const *weight_p = ctx->weight;
  47     for (a_size output_i = 0; output_i != ctx->output_n; ++output_i)
  48     {
  49         ctx->output_p[output_i] = 0;
  50         for (a_size hidden = 0; hidden != ctx->hidden_n; ++hidden)
  51         {
  52             ctx->output_p[output_i] += *weight_p++ * ctx->hidden_p[hidden];
  53         }
  54     }
  55     return ctx->output_p;
  56 }
  57
  58 void a_rbf_tune(a_rbf const *ctx, a_float const *out)
  59 {
  60     a_float *weight = ctx->weight;
  61     a_float *deltaw = ctx->deltaw;
  62     for (a_size output_i = 0; output_i != ctx->output_n; ++output_i)
  63     {
  64         a_float error = out[output_i] - ctx->output_p[output_i];
  65         for (a_size hidden_i = 0; hidden_i != ctx->hidden_n; ++hidden_i)
  66         {
  67             *deltaw = ctx->learn * error * ctx->hidden_p[hidden_i] + ctx->alpha * *deltaw;
  68             *weight++ += *deltaw++;
  69         }
  70     }
  71 }
  72
  73 void a_rbf_zero(a_rbf const *ctx)
  74 {
  75     a_size const hidden_output_n = ctx->hidden_n * ctx->output_n;
  76     a_zero(ctx->input_p, sizeof(a_float) * ctx->input_n);
  77     a_zero(ctx->hidden_p, sizeof(a_float) * ctx->hidden_n);
  78     a_zero(ctx->output_p, sizeof(a_float) * ctx->output_n);
  79     a_zero(ctx->weight, sizeof(a_float) * hidden_output_n);
  80     a_zero(ctx->deltaw, sizeof(a_float) * hidden_output_n);
  81 }