Rcpp::List make_new_labels(T labels,
S posclass,
bool is_pc_na) {
// Variables
Rcpp::List ret_val;
std::string errmsg = "";
std::vector<double> new_labels(labels.size());
int nn = 0;
int np = 0;
std::set<S> label_set;
typename std::set<S>::iterator it;
S lab2 = labels[0];
// Check two labels
for (unsigned i = 0; i < labels.size(); ++i) {
label_set.insert(labels[i]);
}
// Find positive label
if (is_pc_na) {
if (label_set.size() != 2) {
ret_val["errmsg"] = "invalid-labels";
return ret_val;
}
for (it = label_set.begin(); it != label_set.end(); ++it) {
if (lab2 < *it) {
lab2 = *it;
}
}
} else {
it = label_set.find(posclass);
if (it == label_set.end()) {
ret_val["errmsg"] = "invalid-posclass";
return ret_val;
}
lab2 = posclass;
}
// Make new labels - negative 1 & positive 2
for (unsigned i = 0; i < labels.size(); ++i) {
if (labels[i] == lab2) {
++np;
new_labels[i] = 2;
} else {
++nn;
new_labels[i] = 1;
}
}
ret_val["nn"] = nn;
ret_val["np"] = np;
ret_val["labels"] = new_labels;
ret_val["errmsg"] = errmsg;
return ret_val;
}
// Function takes v, w1 & w2 and computes labels:
// (v_lt * (v < v1_thresh)) |
// (w1_lt * (w1 < w1_thresh) &&
// w2_lt * (w2 < w2_thresh)) = -1
// else = +1
//
// [[Rcpp::export]]
float ClassificationError(Rcpp::NumericVector v, float v_thresh, bool v_lt,
Rcpp::NumericVector w1, float w1_thresh, bool w1_lt,
Rcpp::NumericVector w2, float w2_thresh, bool w2_lt,
Rcpp::NumericVector label)
{
assert(v.size() == w1.size());
assert(w1.size() == w2.size());
std::vector<int> new_labels(v.size(),0);
int err = 0;
int count = 0;
for (int i = 0 ; i < v.size() ; i++)
{
bool v_ok = lt_toggle( v[i], v_thresh, v_lt);
bool w1_ok= lt_toggle(w1[i], w1_thresh, w1_lt);
bool w2_ok= lt_toggle(w2[i], w2_thresh, w2_lt);
int label_i = 0;
if (v_ok || (w1_ok && w2_ok))
{
label_i = -1;
}
else
{
label_i = 1;
}
if (label[i] != 0)
{
if (label_i != label[i])
{
err++;
}
count++;
}
}
return float(err) / float(count);
}
