Class: Libsvm::Problem
- Inherits:
-
Object
- Object
- Libsvm::Problem
- Defined in:
- ext/libsvm/libsvm.c
Instance Method Summary collapse
-
#examples ⇒ Object
labels, array_of_arrays = problem.examples.
-
#set_examples(labels, examples_array) ⇒ Object
double *y; // class (aka. label) of the example struct svm_node **x; // examples.
Instance Method Details
#examples ⇒ Object
labels, array_of_arrays = problem.examples
double *y; // class/label of the example struct svm_node **x;
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# File 'ext/libsvm/libsvm.c', line 175 static VALUE cProblem_examples(VALUE problem) { struct svm_problem *prob; struct svm_node *node, *node_copy; double label; struct svm_node *features; VALUE labels_ary, examples_ary, example_ary, v_node, result; int i; Data_Get_Struct(problem, struct svm_problem, prob); labels_ary = rb_ary_new2(prob->l); examples_ary = rb_ary_new2(prob->l); features = calloc(prob->l, sizeof(struct svm_node)); if(features == 0) { rb_raise(rb_eNoMemError, "on allocating Libsvm::Node" " %s:%i", __FILE__,__LINE__); } for(i = 0; i < prob->l; ++i) { label = *(prob->y+i); rb_ary_push(labels_ary,rb_float_new(label)); node = *(prob->x+i); /* example start pointer */ example_ary = rb_ary_new(); while(node->index != -1) { node_copy = malloc(sizeof(struct svm_node)); if(node_copy == 0) { rb_raise(rb_eNoMemError, "on allocating Libsvm::Node" " %s:%i", __FILE__,__LINE__); } memcpy(node_copy,node,sizeof(struct svm_node)); v_node = Data_Wrap_Struct(cNode,0,node_free,node_copy); rb_ary_push(example_ary,v_node); ++node; } rb_ary_push(examples_ary,example_ary); } result = rb_ary_new2(2); rb_ary_push(result,labels_ary); rb_ary_push(result,examples_ary); return result; } |
#set_examples(labels, examples_array) ⇒ Object
double *y; // class (aka. label) of the example
struct svm_node **x; // examples
This method sets the contents of an SVM Problem, which consists of lables (or classifications) and examples (or feature vectors). If those 2 don’t match in length and ArgumentError is raised.
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# File 'ext/libsvm/libsvm.c', line 132 static VALUE cProblem_examples_set(VALUE obj,VALUE labels_ary,VALUE examples_ary) { struct svm_problem *prob; int i; int num = rx_ary_size(labels_ary); if(num != rx_ary_size(examples_ary)) { rb_raise(rb_eArgError, "Number of labels (%i) does not match number of features (%i).", num, rx_ary_size(examples_ary)); } Data_Get_Struct(obj, struct svm_problem, prob); if(prob->l > 0) { free(prob->y); for(i = 0; i < num; ++i) { free(*(prob->x+i)); } free(prob->x); } prob->y = calloc(num,sizeof(double)); if(prob->y == 0) { rb_raise(rb_eNoMemError, "%s:%i", __FILE__,__LINE__); } for(i = 0; i < num; ++i) { *(prob->y+i) = NUM2DBL(rb_ary_entry(labels_ary,i)); } prob->x = examples_ary_to_internal(examples_ary); prob->l = num; return INT2FIX(num); } |