Class: Libsvm::Model

Inherits:

Object

• Object
• Libsvm::Model

Defined in:

ext/libsvm/libsvm.c

Class Method Summary

• .cross_validation(problem, parameter, num_fold) ⇒ Object
• .load(filename) ⇒ Object
• .train(problem, parameter) ⇒ Object

  Libsvm::Model.

Instance Method Summary

• #classes ⇒ Object
• #predict(example) ⇒ Object
• #predict_probability(example) ⇒ Object
• #save(filename) ⇒ Object
• #svm_type ⇒ Object

Class Method Details

.cross_validation(problem, parameter, num_fold) ⇒ Object

# File 'ext/libsvm/libsvm.c', line 423

static VALUE cModel_class_cross_validation(VALUE cls, VALUE problem, VALUE parameter, VALUE num_fold)
{
  const struct svm_problem *prob;
  const struct svm_parameter *param;
  int nr_fold, i;
  double *target_ptr;
  VALUE target;

  Data_Get_Struct(problem, struct svm_problem, prob);
  Data_Get_Struct(parameter, struct svm_parameter, param);
  
  nr_fold = NUM2INT(num_fold);

  target = rb_ary_new2(prob->l);
  target_ptr = calloc(prob->l, sizeof(double));
  if(target_ptr == 0) {
    rb_raise(rb_eNoMemError, "on cross-validation result allocation" " %s:%i", __FILE__,__LINE__);
  }

  svm_cross_validation(prob, param, nr_fold, target_ptr);

  for(i = 0; i < prob->l; ++i) {
    rb_ary_push(target, rb_float_new(*(target_ptr+i)));
  }

  free(target_ptr);

  return target;
}

.load(filename) ⇒ Object

# File 'ext/libsvm/libsvm.c', line 414

static VALUE cModel_class_load(VALUE cls, VALUE filename)
{
  struct svm_model *model;
  char *path;
  path = StringValueCStr(filename);
  model = svm_load_model(path);
  return Data_Wrap_Struct(cModel, 0, model_free, model);
}

.train(problem, parameter) ⇒ Object

Libsvm::Model

# File 'ext/libsvm/libsvm.c', line 321

static VALUE cModel_class_train(VALUE obj,VALUE problem,VALUE parameter) {
  const struct svm_problem *prob;
  const struct svm_parameter *param;
  struct svm_model *model;
  const char *check_error;

  Data_Get_Struct(problem, struct svm_problem, prob);
  Data_Get_Struct(parameter, struct svm_parameter, param);
  
  check_error = svm_check_parameter(prob, param);
  if(check_error != NULL) {
    rb_raise(rb_eArgError, "Parameters not valid for Problem: '%s'", check_error);
  }
  model = svm_train(prob,param);

  return Data_Wrap_Struct(cModel, 0, model_free, model);
}

Instance Method Details

#classes ⇒ Object

# File 'ext/libsvm/libsvm.c', line 407

static VALUE cModel_classes(VALUE obj) 
{
  const struct svm_model *model;
  Data_Get_Struct(obj, struct svm_model, model);
  return INT2NUM(svm_get_nr_class(model));
}

#predict(example) ⇒ Object

# File 'ext/libsvm/libsvm.c', line 339

static VALUE cModel_predict(VALUE obj,VALUE example) {
  struct svm_node *x;
  struct svm_model *model;
  double class;

  x = example_to_internal(example);
  Data_Get_Struct(obj, struct svm_model, model);
  class = svm_predict(model, x);

  free(x);

  return rb_float_new(class);
}

#predict_probability(example) ⇒ Object

# File 'ext/libsvm/libsvm.c', line 353

static VALUE cModel_predict_probability(VALUE obj,VALUE example) {
  struct svm_node *x;
  struct svm_model *model;
  double class;
  double *c_estimates;
  VALUE estimates;
  VALUE target;
  int i;

  x = example_to_internal(example);
  Data_Get_Struct(obj, struct svm_model, model);
  c_estimates = calloc(model->nr_class, sizeof(double));
  if(c_estimates == 0) {
    rb_raise(rb_eNoMemError, "on predict probability estimates allocation" " %s:%i", __FILE__,__LINE__);
  }

  class = svm_predict_probability(model, x, c_estimates);

  estimates = rb_ary_new();
  for (i = 0; i < model->nr_class; i++)
    rb_ary_push(estimates, rx_from_double(c_estimates[i]));

  free(c_estimates);
  free(x);

  target = rb_ary_new();
  rb_ary_push(target, rb_float_new(class));
  rb_ary_push(target, estimates);
  return target;
}

#save(filename) ⇒ Object

# File 'ext/libsvm/libsvm.c', line 384

static VALUE cModel_save(VALUE obj, VALUE filename)
{
  const struct svm_model *model;
  const char *path;
  int rc; 

  Data_Get_Struct(obj, struct svm_model, model);
  path = StringValueCStr(filename);
  
  if(rc = svm_save_model(path, model)) {
    rb_raise(rb_eStandardError, "Error on saving model, code: %i", rc);
  }
  
  return Qnil;
}

#svm_type ⇒ Object

# File 'ext/libsvm/libsvm.c', line 400

static VALUE cModel_svm_type(VALUE obj)
{
  const struct svm_model *model;
  Data_Get_Struct(obj, struct svm_model, model);
  return INT2NUM(svm_get_svm_type(model));
}