Quaternion to Euler conversion

[Ralph-UP]

Hello,

I have a question related to the quaternion to Euler angle conversion. When I compare the code from

PlotJuggler/plotjuggler_plugins/ToolboxQuaternion/quaternion_to_rpy.cpp

Line 73 in 47a61d7

void QuaternionToRollPitchYaw::calculateNextPoint(size_t index,

to
Roll:

PlotJuggler/plotjuggler_app/resources/default.snippets.xml

Line 94 in 47a61d7

<snippet name="quat_to_roll">

Pitch:

PlotJuggler/plotjuggler_app/resources/default.snippets.xml

Line 110 in 47a61d7

<snippet name="quat_to_pitch">

Yaw:

PlotJuggler/plotjuggler_app/resources/default.snippets.xml

Line 125 in 47a61d7

<snippet name="quat_to_yaw">

I see that the order of the elements is different:

quaternion_to_rpy.cpp
  double q_x = quat[0];
  double q_y = quat[1];
  double q_z = quat[2];
  double q_w = quat[3];

vs.

default.snippets.xml
w = value
x = v1
y = v2
z = v3

Is this intentional ?
Note: My impression is that if you "mismap" the quaternions:
w =q[0]; x = q[1]; y = q[2]; z = q[3];
then the code seems to do the right calculation when compared to
Quaternion to DCM: https://github.com/PX4/PX4-Autopilot/blob/1dacb4cdef2d7145754fc788fa8dc482eed74b40/src/lib/matrix/matrix/Dcm.hpp#L86
DCM to Euler: https://github.com/PX4/PX4-Autopilot/blob/1dacb4cdef2d7145754fc788fa8dc482eed74b40/src/lib/matrix/matrix/Euler.hpp#L92

I understand that this a very specific issue, please take with a grain of salt -- I don't want to raise this as an issue.

BR

Ralph Paul