1 files changed, 80 insertions, 0 deletions
diff --git a/src/crossval.c b/src/crossval.c
new file mode 100644
index 0000000..9a3c1cc
--- /dev/null
+++ b/src/crossval.c
@@ -0,0 +1,80 @@
+#include "crossval.h"
+#include "matrix.h"
+#include "MSVMMaj.h"
+
+void msvmmaj_make_cv_split(long N, long folds, long *cv_idx)
+{
+	long i, j, idx;
+
+	long big_folds = N%folds;
+	long small_fold_size = N/folds;
+	
+	j = 0;
+	for (i=0; i<small_fold_size*folds; i++)
+		while (1) {
+			idx = rand()%N;
+			if (cv_idx[idx] == 0) {
+				cv_idx[idx] = j;
+				j++;
+				j%=folds;
+				break;
+			}
+		}
+	j = 0;
+	i = 0;
+	while (i < big_folds) {
+		if (cv_idx[j] == 0) {
+			cv_idx[j] = i++;
+		}
+		j++;
+	}
+}
+
+void msvmmaj_get_tt_split(struct MajData *full_data, struct MajData *train_data,
+		struct MajData *test_data, long *cv_idx, long fold_idx)
+{
+	long i, j, k, l, test_n, train_n;
+
+	long n = full_data->n;
+	long m = full_data->m;
+	long K = full_data->K;
+
+	test_n = 0;
+	for (i=0; i<n; i++)
+		if (cv_idx[i] == fold_idx)
+			test_n++;
+	train_n = n - test_n;
+
+	test_data->n = test_n;
+	train_data->n = train_n;
+
+	train_data->K = K;
+	test_data->K = K;
+
+	train_data->m = m;
+	test_data->m = m;
+
+	train_data->y = Calloc(long, train_n);
+	test_data->y = Calloc(long, test_n);
+
+	train_data->Z = Calloc(double, train_n*(m+1));
+	test_data->Z = Calloc(double, test_n*(m+1));
+
+	k = 0;
+	l = 0;
+	for (i=0; i<n; i++) {
+		if (cv_idx[i] == fold_idx) {
+			test_data->y[k] = full_data->y[i];
+			for (j=0; j<m+1; j++)
+				matrix_set(test_data->Z, m+1, k, j, 
+						matrix_get(full_data->Z, m+1, i, j));
+			k++;
+		} else {
+			train_data->y[l] = full_data->y[i];
+			for (j=0; j<m+1; j++)
+				matrix_set(train_data->Z, m+1, l, j,
+						matrix_get(full_data->Z, m+1, i, j));
+			l++;
+		}
+	}
+}