Start trying to handle also egde and big error cases in error handling.

1 files changed, 9 insertions, 8 deletions

diff --git a/double-error.c b/double-error.c
index 4cd1406..a918cff 100644
--- a/double-error.c
+++ b/double-error.c
@@ -17,14 +17,14 @@ double_error convert_int(int i){
 double_error to_exptype(double d){
 	double_error de;
 	de.d = d;
-	de.e = EPS*fabs(d);
+	de.e = max(EPS*fabs(d),DBL_MIN);
 	return de;
 }
 
 double_error sum(double_error de1, double_error de2){
 	double_error de;
 	de.d = de1.d + de2.d;
-	de.e = de1.e + de2.e + ( fabs(de1.d) + fabs(de2.d) + de1.e + de2.e )*EPS;
+	de.e = de1.e + de2.e + ( fabs(de1.d) + fabs(de2.d) + de1.e + de2.e )*EPS + DBL_MIN;
 	return de;
 }
 
@@ -43,10 +43,10 @@ double_error maximum(double_error de1, double_error de2){
 	double max2 = de2.d+de2.e;
 	if( max1 >= max2 ){
 		de.d = de1.d;
-		de.e = de1.e + max1*EPS;
+		de.e = de1.e + max1*EPS + DBL_MIN;
 	} else {
-	de.d = de2.d;
-	de.e = de2.e + max2*EPS;
+		de.d = de2.d;
+		de.e = de2.e + max2*EPS + DBL_MIN;
 	}
 
 	return de;
@@ -59,14 +59,15 @@ double_error product(double_error de1, double_error de2){
 	double p21 = fabs(de2.d)*de1.e;
 	double p22 = de1.e+de2.e;
 	double s = p12 + p21 + p22; 
-	de.e = s + ( fabs(de.d) + s )*EPS;
+	de.e = s + ( fabs(de.d) + s )*EPS + DBL_MIN;
 	return de;
 }
 
 double_error ratio(double_error de1, double_error de2){
 	double_error de2i;
 	de2i.d = 1/de2.d;
-	de2i.e = 2*de2.e/(de2.d*de2.d) + fabs(de2i.d)*EPS; //2* is random extra margin in case error is large
+	if(de2.e > de2.d/2) de2i.e = INFINITY;
+	else de2i.e = 2*de2.e/(de2.d*de2.d) + fabs(de2i.d)*EPS + DBL_MIN; //2* is extra margin in case de2.e is near de2.d/2
 	return product(de1,de2i);
 
 }
@@ -85,7 +86,7 @@ double_error power(double_error de, double_error p) {
 		dep.e = 2*fabs(dep.d)*( de.e/fabs(de.d) + p.e/fabs(p.d) + EPS ); //again random 2*
 	}
 	else {
-		dep.e = de.e + EPS;
+		dep.e = de.e;
 	}
 	return dep;
 }