Fix 'GslibAngles' implementation (#193)

src/rotations.jl

@@ -84,9 +84,13 @@ end
 """
     GslibAngles(θ₁, θ₂, θ₃)
 
-GSLIB ZXY rotation convention following the left-hand rule.
-All angles are in degrees and the signal convention is CW, CCW, CCW
-positive. Y is the principal axis.
+GSLIB YXZ rotation convention following the left-hand rule.
+All angles are in degrees and the sign convention is CW, CCW, CW positive.
+Y is the principal axis.
+
+The first rotation `θ₁` is a rotation around the Z-axis, this is also called the azimuth. 
+The second rotation `θ₂` is a rotation around the X-axis, this is also called the dip. 
+The third rotation `θ₃` is a rotation around the Y-axis, this is also called the tilt. 
 
 ## References
 
@@ -103,26 +107,28 @@ end
 GslibAngles(θ₁::T, θ₂::T, θ₃::T) where {T} = GslibAngles{T}(θ₁, θ₂, θ₃)
 GslibAngles(θ₁, θ₂, θ₃) = GslibAngles(promote(θ₁, θ₂, θ₃)...)
 
-function Base.convert(::Type{R}, rot::RotZYX) where {R<:GslibAngles}
+rottype(::Type{<:GslibAngles}) = RotYXZ
+
+function Base.convert(::Type{R}, rot::RotYXZ) where {R<:GslibAngles}
   θ₁, θ₂, θ₃ = Rotations.params(rot)
-  R(rad2deg(θ₃) + 90, rad2deg(θ₂), -rad2deg(θ₁))
+  R(-rad2deg(θ₃), rad2deg(θ₂), -rad2deg(θ₁))
 end
 
-function Base.convert(::Type{R}, rot::GslibAngles) where {R<:RotZYX}
+function Base.convert(::Type{R}, rot::GslibAngles) where {R<:RotYXZ}
   (; θ₁, θ₂, θ₃) = rot
-  R(-deg2rad(θ₃), deg2rad(θ₂), deg2rad(θ₁ - 90))
+  R(-deg2rad(θ₃), deg2rad(θ₂), -deg2rad(θ₁))
 end
 
 """
     MinesightAngles(θ₁, θ₂, θ₃)
 
-MineSight YZX rotation convention following the right-hand rule.
+MineSight YXZ rotation convention following the right-hand rule.
 All angles are in degrees and the sign convention is CW, CCW, CW positive.
 
-The first rotation is a horizontal rotation around the Z-axis, with positive being clockwise.
-The second rotation is a rotation around the new X-axis, which moves the Y-axis into the
+The first rotation `θ₁` is a horizontal rotation around the Z-axis, with positive being clockwise.
+The second rotation `θ₂` is a rotation around the new X-axis, which moves the Y-axis into the
 desired position, with positive direction of rotation is up.
-The third rotation is a rotation around the new Y-axis, which moves the X-axis into the 
+The third rotation `θ₃` is a rotation around the new Y-axis, which moves the X-axis into the 
 desired position, with positive direction of rotation is up.
 
 ## References

test/rotations.jl

@@ -8,32 +8,31 @@
   @test datamine * v₁ ≈ [3.0810411262386967, 1.2425629737653001, 1.7214014158973259]
   @test datamine * v₂ ≈ [0.7601180732526871, 0.5597366702348654, 0.09442126195411826]
 
-  # GSLIB convention
-  gslib = GslibAngles(70, -30, 20)
-
-  @test gslib * v₁ ≈ [3.0810411262386967, 1.2425629737653001, 1.7214014158973259]
-  @test gslib * v₂ ≈ [0.7601180732526871, 0.5597366702348654, 0.09442126195411826]
-
   # Vulcan convention
   vulcan = VulcanAngles(70, -30, -20)
 
   @test vulcan * v₁ ≈ [3.0810411262386967, 1.2425629737653001, 1.7214014158973259]
   @test vulcan * v₂ ≈ [0.7601180732526871, 0.5597366702348654, 0.09442126195411826]
 
+  # GSLIB convention
+  gslib = GslibAngles(30, 15, -15)
+
+  @test gslib * v₁ ≈ [3.7410191941252595, -0.034675177060507156, 0.059774754555877996]
+  @test gslib * v₂ ≈ [0.8592918193713616, 0.4018496819077273, -0.011593201115905286]
+
   # MineSight convention
-  minisight = MinesightAngles(30, 15, -15)
+  minesight = MinesightAngles(30, 15, -15)
 
-  @test minisight * v₁ ≈ [3.7410191941252595, -0.034675177060507156, 0.059774754555877996]
-  @test minisight * v₂ ≈ [0.8592918193713616, 0.4018496819077273, -0.011593201115905286]
+  @test minesight * v₁ ≈ [3.7410191941252595, -0.034675177060507156, 0.059774754555877996]
+  @test minesight * v₂ ≈ [0.8592918193713616, 0.4018496819077273, -0.011593201115905286]
 
   # comparing conventions
-  @test datamine ≈ gslib
   @test datamine ≈ vulcan
-  @test gslib ≈ vulcan
+  @test gslib ≈ minesight
 
   # rotation conversion
   rot = RotZXY(0.1, 0.2, 0.3)
-  @test DatamineAngles(rot) ≈ GslibAngles(rot) ≈ VulcanAngles(rot) ≈ rot
+  @test DatamineAngles(rot) ≈ VulcanAngles(rot) ≈ rot
 
   θ₁, θ₂, θ₃ = -15, 45, 30
   rot = RotZYX(deg2rad(θ₃), -deg2rad(θ₂), deg2rad(θ₁ - 90))
@@ -44,13 +43,11 @@
   vulcan = VulcanAngles(rot)
   @test Rotations.params(vulcan) ≈ [θ₁, θ₂, θ₃]
 
-  rot = RotZYX(-deg2rad(θ₃), deg2rad(θ₂), deg2rad(θ₁ - 90))
-  gslib = GslibAngles(rot)
-  @test Rotations.params(gslib) ≈ [θ₁, θ₂, θ₃]
-
   θ₁, θ₂, θ₃ = 30, 15, -15
   rot = RotYXZ(-deg2rad(θ₃), deg2rad(θ₂), -deg2rad(θ₁))
-  minisight = MinesightAngles(rot)
-  @test minisight ≈ rot
-  @test Rotations.params(minisight) ≈ [θ₁, θ₂, θ₃]
+  gslib = GslibAngles(rot)
+  minesight = MinesightAngles(rot)
+  @test gslib ≈ minesight ≈ rot
+  @test Rotations.params(gslib) ≈ [θ₁, θ₂, θ₃]
+  @test Rotations.params(minesight) ≈ [θ₁, θ₂, θ₃]
 end