Sync public subset from Flux (private)

include/modules/neural_networks/datasets/spiral.h

@@ -0,0 +1,42 @@
+#pragma once
+
+#include "./core/omp_config.h"
+#include "./utils/matrix.h"
+#include "./utils/vector.h"
+#include "./utils/random.h"
+
+//#include <math.h>
+
+
+namespace neural_networks{
+
+		template <typename TX, typename Ty>
+		void create_spital_data(const uint64_t samples, const uint64_t classes, utils::Matrix<TX>& X, utils::Vector<Ty>& y) {
+
+			const uint64_t rows = samples*classes;
+			TX r, t;
+			uint64_t row_idx;
+
+
+			if ((rows != X.rows()) || (X.cols() != 2)){
+				X.resize(samples*classes, 2);
+			}
+			if (rows != y.size()){
+				y.resize(rows);
+			}
+
+			for (uint64_t i = 0; i < classes; ++i){
+				for (uint64_t j = 0; j < samples; ++j){
+					r = static_cast<TX>(j)/static_cast<TX>(samples);
+					t =  static_cast<TX>(i)*4.0 + (4.0+r);
+					row_idx = (i*samples) + j;
+
+					X(row_idx, 0) = r*std::cos(t*2.5) + utils::random(TX{-0.15}, TX{0.15});
+					X(row_idx, 1) = r*std::sin(t*2.5) + utils::random(TX{-0.15}, TX{0.15});
+					y[row_idx] = static_cast<Ty>(i);
+				}
+			}
+		}
+
+
+} // end namesoace NN