1 files changed, 94 insertions, 0 deletions
diff --git a/src/roots.c b/src/roots.c
new file mode 100644
index 0000000..0aef762
--- /dev/null
+++ b/src/roots.c
@@ -0,0 +1,94 @@
+#include "roots.h"
+#include <math.h>
+#include <stdio.h>
+
+char root_ok = 1;
+
+// функция для проверки того, успешно ли выполнилась последняя функция
+char is_root_ok(void) {
+	return root_ok;
+}
+
+// метод дихтомии
+double sol_binsr(f_t f, double a, double b, double ex, double ey) {
+	if (copysign(1.0, f(a)) == copysign(1.0, f(b))) {
+		root_ok = 0;
+		return NAN;
+	}
+	
+	double mid;
+	do {
+		mid = (a + b) / 2;
+		if (copysign(1.0, f(a)) != copysign(1.0, f(mid))) b = mid;
+		else a = mid;
+	} while (f(mid) > ey || (b-a) > ex);
+	root_ok = 1;
+	return mid;
+}
+
+// метод хорд
+double sol_chord(f_t f, double a, double b, double ex, double ey) {
+	if (copysign(1.0, f(a)) == copysign(1.0, f(b))) {
+		root_ok = 0;
+		return NAN;
+	}
+	double mid = a + fabs( f(a) / (f(b)-f(a)) ) * (b-a);
+	double diff = mid;
+	while (f(mid) > ey || fabs(diff - mid) > ex) {
+		diff = mid;
+		mid = a + fabs( f(a) / (f(b)-f(a)) ) * (b-a);
+		if (copysign(1.0, f(a)) != copysign(1.0, f(mid))) b = mid;
+		else a = mid;
+	}
+	root_ok = 1;
+	return mid;
+
+}
+
+// метод касательных (Ньютона)
+double sol_newtn(f_t f, double x0, double ex, double ey) {
+	const double dx = 1e-6;
+	double diff = x0+2*ex;
+
+	// check for divergence
+	double d2x0 = (f(x0 + 2*dx) - 2*f(x0 + dx) + f(x0))/(dx*dx);
+	if (copysign(1.0, d2x0) != copysign(1.0, f(x0))) {
+		root_ok = 0;
+		return NAN;
+	}
+	while ((fabs(diff - x0) > ex || f(x0) > ey)) {
+		double fx0 = f(x0);
+		double dx0 = (f(x0+dx) - fx0) / dx;
+		diff = x0;
+		x0 -= fx0/dx0;
+		if (isinf(x0) || isnan(x0)) {
+			root_ok = 0;
+			return NAN;
+		}
+	}
+	root_ok = 1;
+	return x0;
+}
+
+// метод итераций
+double sol_itern(f_t f, double x0, double ex, double ey) {
+	const double dx = 1e-6;
+	double diff = x0 + 2*ex;
+
+	do {
+		double dx0 = (f(x0+dx) - f(x0))/dx;
+		if (fabs(dx0) > 1.0) {
+			root_ok = 0;
+			return NAN;
+		}
+		diff = x0;
+		x0 = f(x0);
+		printf("x0=%lf, f(x0)=%lf\n", x0, f(x0));
+		getchar();
+	} while (fabs(diff - x0) > ex || fabs(f(x0) - x0) > ey);
+	root_ok = 1;
+	return x0;
+}
+
+
+