creating training data from an array

dukhat · **Joined:** Sat Mar 10, 2007 5:24 pm **Posts:** 11

Hi everyone. As far as I can tell, there is no way in FANN to create training data from an array. I wrote some code, pasted below, that does this. It only works with doubles and not FANN_TYPE at the moment, but someone can probably easily fix it. I don't really know what I am doing, but this seems to work for my purposes. If someone more familiar with the code base would like to change it to work with FANN_TYPE and give it a quick test and commit it that would be great. I basically modified the fann read training data from file function. Use the code at your own risk, I thought it might be useful to people and that someone could use it to quickly add that functionality to the library.

- George

Code:

struct fann_train_data *read_from_array(double *din, double *dout, unsigned int num_data,
unsigned int num_input, unsigned int num_output) {
  unsigned int i, j;
  fann_type *data_input, *data_output;
  struct fann_train_data *data =
    (struct fann_train_data *) malloc(sizeof(struct fann_train_data));
  if(data == NULL) {
    fann_error(NULL, FANN_E_CANT_ALLOCATE_MEM);
    return NULL;
  }
 
  fann_init_error_data((struct fann_error *) data);
 
  data->num_data = num_data;
  data->num_input = num_input;
  data->num_output = num_output;
  data->input = (double **) calloc(num_data, sizeof(double *));
  if(data->input == NULL) {
    fann_error(NULL, FANN_E_CANT_ALLOCATE_MEM);
    fann_destroy_train(data);
    return NULL;
  }
 
  data->output = (double **) calloc(num_data, sizeof(double *));
  if(data->output == NULL) {
    fann_error(NULL, FANN_E_CANT_ALLOCATE_MEM);
    fann_destroy_train(data);
    return NULL;
  }
 
  data_input = (double *) calloc(num_input * num_data, sizeof(double));
  if(data_input == NULL) {
    fann_error(NULL, FANN_E_CANT_ALLOCATE_MEM);
    fann_destroy_train(data);
    return NULL;
  }
 
  data_output = (double *) calloc(num_output * num_data, sizeof(double));
  if(data_output == NULL) {
    fann_error(NULL, FANN_E_CANT_ALLOCATE_MEM);
    fann_destroy_train(data);
    return NULL;
  }
 
  for(i = 0; i != num_data; i++) {
    data->input[i] = data_input;
    data_input += num_input;
   
    for(j = 0; j != num_input; j++) {
      data->input[i][j] = din[i*num_input+j];
    }
   
   
    data->output[i] = data_output;
    data_output += num_output;
   
    for(j = 0; j != num_output; j++) {
      data->output[i][j] = dout[i*num_output+j];
    }
  }
  return data;
}

FANN Forum