Merge pull request #20878 from tiehuis/std-math-complex-fixes

std.math.complex fixes

Author: andrewrk

lib/std/math/complex/abs.zig

@@ -9,10 +9,9 @@ pub fn abs(z: anytype) @TypeOf(z.re, z.im) {
     return math.hypot(z.re, z.im);
 }
 
-const epsilon = 0.0001;
-
 test abs {
+    const epsilon = math.floatEps(f32);
     const a = Complex(f32).init(5, 3);
     const c = abs(a);
-    try testing.expect(math.approxEqAbs(f32, c, 5.83095, epsilon));
+    try testing.expectApproxEqAbs(5.8309517, c, epsilon);
 }

lib/std/math/complex/acos.zig

@@ -11,12 +11,11 @@ pub fn acos(z: anytype) Complex(@TypeOf(z.re, z.im)) {
     return Complex(T).init(@as(T, math.pi) / 2 - q.re, -q.im);
 }
 
-const epsilon = 0.0001;
-
 test acos {
+    const epsilon = math.floatEps(f32);
     const a = Complex(f32).init(5, 3);
     const c = acos(a);
 
-    try testing.expect(math.approxEqAbs(f32, c.re, 0.546975, epsilon));
-    try testing.expect(math.approxEqAbs(f32, c.im, -2.452914, epsilon));
+    try testing.expectApproxEqAbs(0.5469737, c.re, epsilon);
+    try testing.expectApproxEqAbs(-2.4529128, c.im, epsilon);
 }

lib/std/math/complex/acosh.zig

@@ -8,15 +8,18 @@ const Complex = cmath.Complex;
 pub fn acosh(z: anytype) Complex(@TypeOf(z.re, z.im)) {
     const T = @TypeOf(z.re, z.im);
     const q = cmath.acos(z);
-    return Complex(T).init(-q.im, q.re);
-}
 
-const epsilon = 0.0001;
+    return if (math.signbit(z.im))
+        Complex(T).init(q.im, -q.re)
+    else
+        Complex(T).init(-q.im, q.re);
+}
 
 test acosh {
+    const epsilon = math.floatEps(f32);
     const a = Complex(f32).init(5, 3);
     const c = acosh(a);
 
-    try testing.expect(math.approxEqAbs(f32, c.re, 2.452914, epsilon));
-    try testing.expect(math.approxEqAbs(f32, c.im, 0.546975, epsilon));
+    try testing.expectApproxEqAbs(2.4529128, c.re, epsilon);
+    try testing.expectApproxEqAbs(0.5469737, c.im, epsilon);
 }

lib/std/math/complex/arg.zig

@@ -9,10 +9,9 @@ pub fn arg(z: anytype) @TypeOf(z.re, z.im) {
     return math.atan2(z.im, z.re);
 }
 
-const epsilon = 0.0001;
-
 test arg {
+    const epsilon = math.floatEps(f32);
     const a = Complex(f32).init(5, 3);
     const c = arg(a);
-    try testing.expect(math.approxEqAbs(f32, c, 0.540420, epsilon));
+    try testing.expectApproxEqAbs(0.5404195, c, epsilon);
 }

lib/std/math/complex/asin.zig

@@ -17,12 +17,11 @@ pub fn asin(z: anytype) Complex(@TypeOf(z.re, z.im)) {
     return Complex(T).init(r.im, -r.re);
 }
 
-const epsilon = 0.0001;
-
 test asin {
+    const epsilon = math.floatEps(f32);
     const a = Complex(f32).init(5, 3);
     const c = asin(a);
 
-    try testing.expect(math.approxEqAbs(f32, c.re, 1.023822, epsilon));
-    try testing.expect(math.approxEqAbs(f32, c.im, 2.452914, epsilon));
+    try testing.expectApproxEqAbs(1.0238227, c.re, epsilon);
+    try testing.expectApproxEqAbs(2.4529128, c.im, epsilon);
 }

lib/std/math/complex/asinh.zig

@@ -12,12 +12,11 @@ pub fn asinh(z: anytype) Complex(@TypeOf(z.re, z.im)) {
     return Complex(T).init(r.im, -r.re);
 }
 
-const epsilon = 0.0001;
-
 test asinh {
+    const epsilon = math.floatEps(f32);
     const a = Complex(f32).init(5, 3);
     const c = asinh(a);
 
-    try testing.expect(math.approxEqAbs(f32, c.re, 2.459831, epsilon));
-    try testing.expect(math.approxEqAbs(f32, c.im, 0.533999, epsilon));
+    try testing.expectApproxEqAbs(2.4598298, c.re, epsilon);
+    try testing.expectApproxEqAbs(0.5339993, c.im, epsilon);
 }

lib/std/math/complex/atan.zig

@@ -32,37 +32,22 @@ fn redupif32(x: f32) f32 {
         t -= 0.5;
     }
 
-    const u = @as(f32, @floatFromInt(@as(i32, @intFromFloat(t))));
-    return ((x - u * DP1) - u * DP2) - t * DP3;
+    const u: f32 = @trunc(t);
+    return ((x - u * DP1) - u * DP2) - u * DP3;
 }
 
 fn atan32(z: Complex(f32)) Complex(f32) {
-    const maxnum = 1.0e38;
-
     const x = z.re;
     const y = z.im;
 
-    if ((x == 0.0) and (y > 1.0)) {
-        // overflow
-        return Complex(f32).init(maxnum, maxnum);
-    }
-
     const x2 = x * x;
     var a = 1.0 - x2 - (y * y);
-    if (a == 0.0) {
-        // overflow
-        return Complex(f32).init(maxnum, maxnum);
-    }
 
     var t = 0.5 * math.atan2(2.0 * x, a);
     const w = redupif32(t);
 
     t = y - 1.0;
     a = x2 + t * t;
-    if (a == 0.0) {
-        // overflow
-        return Complex(f32).init(maxnum, maxnum);
-    }
 
     t = y + 1.0;
     a = (x2 + (t * t)) / a;
@@ -81,57 +66,42 @@ fn redupif64(x: f64) f64 {
         t -= 0.5;
     }
 
-    const u = @as(f64, @floatFromInt(@as(i64, @intFromFloat(t))));
-    return ((x - u * DP1) - u * DP2) - t * DP3;
+    const u: f64 = @trunc(t);
+    return ((x - u * DP1) - u * DP2) - u * DP3;
 }
 
 fn atan64(z: Complex(f64)) Complex(f64) {
-    const maxnum = 1.0e308;
-
     const x = z.re;
     const y = z.im;
 
-    if ((x == 0.0) and (y > 1.0)) {
-        // overflow
-        return Complex(f64).init(maxnum, maxnum);
-    }
-
     const x2 = x * x;
     var a = 1.0 - x2 - (y * y);
-    if (a == 0.0) {
-        // overflow
-        return Complex(f64).init(maxnum, maxnum);
-    }
 
     var t = 0.5 * math.atan2(2.0 * x, a);
     const w = redupif64(t);
 
     t = y - 1.0;
     a = x2 + t * t;
-    if (a == 0.0) {
-        // overflow
-        return Complex(f64).init(maxnum, maxnum);
-    }
 
     t = y + 1.0;
     a = (x2 + (t * t)) / a;
     return Complex(f64).init(w, 0.25 * @log(a));
 }
 
-const epsilon = 0.0001;
-
 test atan32 {
+    const epsilon = math.floatEps(f32);
     const a = Complex(f32).init(5, 3);
     const c = atan(a);
 
-    try testing.expect(math.approxEqAbs(f32, c.re, 1.423679, epsilon));
-    try testing.expect(math.approxEqAbs(f32, c.im, 0.086569, epsilon));
+    try testing.expectApproxEqAbs(1.423679, c.re, epsilon);
+    try testing.expectApproxEqAbs(0.086569, c.im, epsilon);
 }
 
 test atan64 {
+    const epsilon = math.floatEps(f64);
     const a = Complex(f64).init(5, 3);
     const c = atan(a);
 
-    try testing.expect(math.approxEqAbs(f64, c.re, 1.423679, epsilon));
-    try testing.expect(math.approxEqAbs(f64, c.im, 0.086569, epsilon));
+    try testing.expectApproxEqAbs(1.4236790442393028, c.re, epsilon);
+    try testing.expectApproxEqAbs(0.08656905917945844, c.im, epsilon);
 }

lib/std/math/complex/atanh.zig

@@ -12,12 +12,11 @@ pub fn atanh(z: anytype) Complex(@TypeOf(z.re, z.im)) {
     return Complex(T).init(r.im, -r.re);
 }
 
-const epsilon = 0.0001;
-
 test atanh {
+    const epsilon = math.floatEps(f32);
     const a = Complex(f32).init(5, 3);
     const c = atanh(a);
 
-    try testing.expect(math.approxEqAbs(f32, c.re, 0.146947, epsilon));
-    try testing.expect(math.approxEqAbs(f32, c.im, 1.480870, epsilon));
+    try testing.expectApproxEqAbs(0.14694665, c.re, epsilon);
+    try testing.expectApproxEqAbs(1.4808695, c.im, epsilon);
 }

lib/std/math/complex/conj.zig

@@ -14,5 +14,6 @@ test conj {
     const a = Complex(f32).init(5, 3);
     const c = a.conjugate();
 
-    try testing.expect(c.re == 5 and c.im == -3);
+    try testing.expectEqual(5, c.re);
+    try testing.expectEqual(-3, c.im);
 }

lib/std/math/complex/cos.zig

@@ -11,12 +11,11 @@ pub fn cos(z: anytype) Complex(@TypeOf(z.re, z.im)) {
     return cmath.cosh(p);
 }
 
-const epsilon = 0.0001;
-
 test cos {
+    const epsilon = math.floatEps(f32);
     const a = Complex(f32).init(5, 3);
     const c = cos(a);
 
-    try testing.expect(math.approxEqAbs(f32, c.re, 2.855815, epsilon));
-    try testing.expect(math.approxEqAbs(f32, c.im, 9.606383, epsilon));
+    try testing.expectApproxEqAbs(2.8558152, c.re, epsilon);
+    try testing.expectApproxEqAbs(9.606383, c.im, epsilon);
 }