Add trigonometry functions for calculations on MCU

table_sincos/sqrt.c

@@ -0,0 +1,43 @@
+/*
+ * sqrt.c - Newton sqrt
+ *
+ * Copyright 2016 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+#define _XOPEN_SOURCE 1111
+#include <stdio.h>
+#include <math.h>
+#include <stdlib.h>
+
+float SQRT(float x, int iter){
+	float Result;
+	int i = 0;
+	Result = x;
+	for (i; i < iter; i++)
+		Result = (Result + x / Result) / 2;
+	return Result;
+}
+
+int main(int argc, char **argv){
+	if(argc != 2) return 1;
+	float x = strtof(argv[1], NULL);
+	if(x < 0) return 2;
+	printf("sqr(%f) = %f, by 6iter: %f, by 8iter: %f, by 16iter: %f\n", x, sqrtf(x),
+		SQRT(x, 6), SQRT(x, 8), SQRT(x, 16));
+	return 0;
+}
+