diff --git a/nalgebra-glm/src/constructors.rs b/nalgebra-glm/src/constructors.rs
index 6d0463ce..25a3432f 100644
--- a/nalgebra-glm/src/constructors.rs
+++ b/nalgebra-glm/src/constructors.rs
@@ -134,5 +134,5 @@ pub fn mat4<N: Scalar>(m11: N, m12: N, m13: N, m14: N, m21: N, m22: N, m23: N, m
 
 /// Creates a new quaternion.
 pub fn quat<N: Real>(x: N, y: N, z: N, w: N) -> Qua<N> {
-    Qua::new(x, y, z, w)
+    Qua::new(w, x, y, z)
 }
diff --git a/nalgebra-glm/src/ext/scalar_common.rs b/nalgebra-glm/src/ext/scalar_common.rs
index 6829326d..a94bc294 100644
--- a/nalgebra-glm/src/ext/scalar_common.rs
+++ b/nalgebra-glm/src/ext/scalar_common.rs
@@ -12,12 +12,12 @@ pub fn max4_scalar<N: Number>(a: N, b: N, c: N, d: N) -> N {
     na::sup(&na::sup(&a, &b), &na::sup(&c, &d))
 }
 
-/// Returns the maximum among three values.
+/// Returns the minimum among three values.
 pub fn min3_scalar<N: Number>(a: N, b: N, c: N) -> N {
     na::inf(&na::inf(&a, &b), &c)
 }
 
-/// Returns the maximum among four values.
+/// Returns the minimum among four values.
 pub fn min4_scalar<N: Number>(a: N, b: N, c: N, d: N) -> N {
     na::inf(&na::inf(&a, &b), &na::inf(&c, &d))
 }
\ No newline at end of file
diff --git a/nalgebra-glm/src/ext/scalar_constants.rs b/nalgebra-glm/src/ext/scalar_constants.rs
index 89e3746c..f4a25718 100644
--- a/nalgebra-glm/src/ext/scalar_constants.rs
+++ b/nalgebra-glm/src/ext/scalar_constants.rs
@@ -1,7 +1,7 @@
 use approx::AbsDiffEq;
 use na::Real;
 
-/// Default epsilon value used for apporximate comparison.
+/// Default epsilon value used for approximate comparison.
 pub fn epsilon<N: AbsDiffEq<Epsilon = N>>() -> N {
     N::default_epsilon()
 }
diff --git a/nalgebra-glm/src/gtc/constants.rs b/nalgebra-glm/src/gtc/constants.rs
index 39255ecd..92495a4a 100644
--- a/nalgebra-glm/src/gtc/constants.rs
+++ b/nalgebra-glm/src/gtc/constants.rs
@@ -78,7 +78,7 @@ pub fn root_half_pi<N: Real>() -> N {
 
 /// Returns `sqrt(ln(4))`.
 pub fn root_ln_four<N: Real>() -> N {
-    na::convert::<_, N>(4.0).sqrt()
+    na::convert::<_, N>(4.0).ln().sqrt()
 }
 
 /// Returns the square root of pi.
@@ -104,7 +104,7 @@ pub fn root_two_pi<N: Real>() -> N {
 
 /// Returns `1 / 3`.
 pub fn third<N: Real>() -> N {
-    na::convert(1.0 / 2.0)
+    na::convert(1.0 / 3.0)
 }
 
 /// Returns `3 / (2pi)`.
@@ -119,7 +119,7 @@ pub fn two_over_pi<N: Real>() -> N {
 
 /// Returns `2 / sqrt(pi)`.
 pub fn two_over_root_pi<N: Real>() -> N {
-    N::frac_2_pi()
+    N::frac_2_sqrt_pi()
 }
 
 /// Returns `2pi`.
diff --git a/nalgebra-glm/src/gtc/quaternion.rs b/nalgebra-glm/src/gtc/quaternion.rs
index 51bbd968..4487dbc0 100644
--- a/nalgebra-glm/src/gtc/quaternion.rs
+++ b/nalgebra-glm/src/gtc/quaternion.rs
@@ -34,6 +34,7 @@ pub fn quat_less_than_equal<N: Real>(x: &Qua<N>, y: &Qua<N>) -> TVec<bool, U4> {
 pub fn quat_cast<N: Real>(x: &Qua<N>) -> TMat4<N> {
     ::quat_to_mat4(x)
 }
+
 /// Computes a right-handed look-at quaternion (equivalent to a right-handed look-at matrix).
 pub fn quat_look_at<N: Real>(direction: &TVec3<N>, up: &TVec3<N>) -> Qua<N> {
     quat_look_at_rh(direction, up)
diff --git a/nalgebra-glm/src/gtx/matrix_cross_product.rs b/nalgebra-glm/src/gtx/matrix_cross_product.rs
index de01bcc9..482127dd 100644
--- a/nalgebra-glm/src/gtx/matrix_cross_product.rs
+++ b/nalgebra-glm/src/gtx/matrix_cross_product.rs
@@ -9,13 +9,5 @@ pub fn matrix_cross3<N: Real>(x: &TVec3<N>) -> TMat3<N> {
 
 /// Builds a 4x4 matrix `m` such that for any `v`: `m * v == cross(x, v)`.
 pub fn matrix_cross<N: Real>(x: &TVec3<N>) -> TMat4<N> {
-    let m = x.cross_matrix();
-
-    // FIXME: use a dedicated constructor from Matrix3 to Matrix4.
-    TMat4::new(
-        m.m11, m.m12, m.m13, N::zero(),
-        m.m21, m.m22, m.m23, N::zero(),
-        m.m31, m.m32, m.m33, N::zero(),
-        N::zero(), N::zero(), N::zero(), N::one(),
-    )
+    ::mat3_to_mat4(&x.cross_matrix())
 }
diff --git a/nalgebra-glm/src/gtx/matrix_operation.rs b/nalgebra-glm/src/gtx/matrix_operation.rs
index bf05cbb9..bba7bc88 100644
--- a/nalgebra-glm/src/gtx/matrix_operation.rs
+++ b/nalgebra-glm/src/gtx/matrix_operation.rs
@@ -17,7 +17,7 @@ pub fn diagonal2x4<N: Number>(v: &TVec2<N>) -> TMat2x4<N> {
 }
 
 /// Builds a 3x2 diagonal matrix.
-pub fn diagonal3x2<N: Number>(v: &TVec3<N>) -> TMat3x2<N> {
+pub fn diagonal3x2<N: Number>(v: &TVec2<N>) -> TMat3x2<N> {
     TMat3x2::from_partial_diagonal(v.as_slice())
 }
 
@@ -32,12 +32,12 @@ pub fn diagonal3x4<N: Number>(v: &TVec3<N>) -> TMat3x4<N> {
 }
 
 /// Builds a 4x2 diagonal matrix.
-pub fn diagonal4x2<N: Number>(v: &TVec4<N>) -> TMat4x2<N> {
+pub fn diagonal4x2<N: Number>(v: &TVec2<N>) -> TMat4x2<N> {
     TMat4x2::from_partial_diagonal(v.as_slice())
 }
 
 /// Builds a 4x3 diagonal matrix.
-pub fn diagonal4x3<N: Number>(v: &TVec4<N>) -> TMat4x3<N> {
+pub fn diagonal4x3<N: Number>(v: &TVec3<N>) -> TMat4x3<N> {
     TMat4x3::from_partial_diagonal(v.as_slice())
 }
 
diff --git a/nalgebra-glm/src/gtx/norm.rs b/nalgebra-glm/src/gtx/norm.rs
index a532fc3f..a59b50cf 100644
--- a/nalgebra-glm/src/gtx/norm.rs
+++ b/nalgebra-glm/src/gtx/norm.rs
@@ -12,7 +12,7 @@ pub fn distance2<N: Real, D: Dimension>(p0: &TVec<N, D>, p1: &TVec<N, D>) -> N
 /// The l1-norm of `x - y`.
 pub fn l1_distance<N: Real, D: Dimension>(x: &TVec<N, D>, y: &TVec<N, D>) -> N
     where DefaultAllocator: Alloc<N, D> {
-    l1_norm(&(x - y))
+    l1_norm(&(y - x))
 }
 
 /// The l1-norm of `v`.
diff --git a/nalgebra-glm/src/gtx/quaternion.rs b/nalgebra-glm/src/gtx/quaternion.rs
index 290c7150..1023aa76 100644
--- a/nalgebra-glm/src/gtx/quaternion.rs
+++ b/nalgebra-glm/src/gtx/quaternion.rs
@@ -48,7 +48,6 @@ pub fn quat_rotate_vec3<N: Real>(q: &Qua<N>, v: &TVec3<N>) -> TVec3<N> {
 
 /// Rotates a vector in homogeneous coordinates by a quaternion assumed to be normalized.
 pub fn quat_rotate_vec<N: Real>(q: &Qua<N>, v: &TVec4<N>) -> TVec4<N> {
-//    UnitQuaternion::new_unchecked(*q) * v
     let rotated = Unit::new_unchecked(*q) * v.fixed_rows::<U3>(0);
     TVec4::new(rotated.x, rotated.y, rotated.z, v.w)
 }