X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=ginac%2Finifcns_trans.cpp;h=c8a0a8214ca7f276da625096c36899cdd1be9d78;hp=3f161d218c068e2a4d016fce5d5cfcb2d32f789e;hb=704fe31c78553ffe2058c72bc4d17e6a1ae31350;hpb=7b3b8236e72d939ee9a9c0e83ca3bcf66eec1ce2

diff --git a/ginac/inifcns_trans.cpp b/ginac/inifcns_trans.cpp
index 3f161d21..c8a0a821 100644
--- a/ginac/inifcns_trans.cpp
+++ b/ginac/inifcns_trans.cpp
@@ -822,65 +822,68 @@ static ex atan2_eval(const ex & y, const ex & x)
 {
 	if (y.is_zero()) {
 
-		// atan(0, 0) -> 0
+		// atan2(0, 0) -> 0
 		if (x.is_zero())
 			return _ex0;
 
-		// atan(0, x), x real and positive -> 0
+		// atan2(0, x), x real and positive -> 0
 		if (x.info(info_flags::positive))
 			return _ex0;
 
-		// atan(0, x), x real and negative -> Pi
+		// atan2(0, x), x real and negative -> Pi
 		if (x.info(info_flags::negative))
 			return Pi;
 	}
 
 	if (x.is_zero()) {
 
-		// atan(y, 0), y real and positive -> Pi/2
+		// atan2(y, 0), y real and positive -> Pi/2
 		if (y.info(info_flags::positive))
 			return _ex1_2*Pi;
 
-		// atan(y, 0), y real and negative -> -Pi/2
-		if (y.info(info_flags::real) && !y.is_zero())
+		// atan2(y, 0), y real and negative -> -Pi/2
+		if (y.info(info_flags::negative))
 			return _ex_1_2*Pi;
 	}
 
 	if (y.is_equal(x)) {
 
-		// atan(y, y), y real and positive -> Pi/4
+		// atan2(y, y), y real and positive -> Pi/4
 		if (y.info(info_flags::positive))
 			return _ex1_4*Pi;
 
-		// atan(y, y), y real and negative -> -3/4*Pi
+		// atan2(y, y), y real and negative -> -3/4*Pi
 		if (y.info(info_flags::negative))
 			return numeric(-3, 4)*Pi;
 	}
 
 	if (y.is_equal(-x)) {
 
-		// atan(y, -y), y real and positive -> 3*Pi/4
+		// atan2(y, -y), y real and positive -> 3*Pi/4
 		if (y.info(info_flags::positive))
 			return numeric(3, 4)*Pi;
 
-		// atan(y, -y), y real and negative -> -Pi/4
+		// atan2(y, -y), y real and negative -> -Pi/4
 		if (y.info(info_flags::negative))
 			return _ex_1_4*Pi;
 	}
 
-	// atan(float, float) -> float
+	// atan2(float, float) -> float
 	if (is_a<numeric>(y) && !y.info(info_flags::crational) &&
 	    is_a<numeric>(x) && !x.info(info_flags::crational))
 		return atan(ex_to<numeric>(y), ex_to<numeric>(x));
 
-	// atan(real, real) -> atan(y/x) +/- Pi
+	// atan2(real, real) -> atan(y/x) +/- Pi
 	if (y.info(info_flags::real) && x.info(info_flags::real)) {
 		if (x.info(info_flags::positive))
 			return atan(y/x);
-		else if (y.info(info_flags::positive))
-			return atan(y/x)+Pi;
-		else
-			return atan(y/x)-Pi;
+
+		if (x.info(info_flags::negative)) {
+			if (y.info(info_flags::positive))
+				return atan(y/x)+Pi;
+			if (y.info(info_flags::negative))
+				return atan(y/x)-Pi;
+		}
 	}
 
 	return atan2(y, x).hold();
@@ -891,10 +894,10 @@ static ex atan2_deriv(const ex & y, const ex & x, unsigned deriv_param)
 	GINAC_ASSERT(deriv_param<2);
 	
 	if (deriv_param==0) {
-		// d/dy atan(y,x)
+		// d/dy atan2(y,x)
 		return x*power(power(x,_ex2)+power(y,_ex2),_ex_1);
 	}
-	// d/dx atan(y,x)
+	// d/dx atan2(y,x)
 	return -y*power(power(x,_ex2)+power(y,_ex2),_ex_1);
 }