From d54fe7c1f704a63824c5bfa0ece65245572e9b27 Mon Sep 17 00:00:00 2001 From: Joseph Hunkeler Date: Wed, 4 Mar 2015 21:21:30 -0500 Subject: Initial commit --- src/slalib/sun67.htx/node101.html | 132 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 132 insertions(+) create mode 100644 src/slalib/sun67.htx/node101.html (limited to 'src/slalib/sun67.htx/node101.html') diff --git a/src/slalib/sun67.htx/node101.html b/src/slalib/sun67.htx/node101.html new file mode 100644 index 0000000..e5bdda2 --- /dev/null +++ b/src/slalib/sun67.htx/node101.html @@ -0,0 +1,132 @@ + + + + +SLA_EULER - Rotation Matrix from Euler Angles + + + + + + + + + + + + +
+ +next + +up + +previous +
+ Next: SLA_EVP - Earth Position & Velocity +
+Up: SUBPROGRAM SPECIFICATIONS +
+ Previous: SLA_ETRMS - E-terms of Aberration +

+

+

SLA_EULER - Rotation Matrix from Euler Angles +   +

+
+
ACTION: +
Form a rotation matrix from the Euler angles - three +successive rotations about specified Cartesian axes + (single precision). +

CALL: +
CALL sla_EULER (ORDER, PHI, THETA, PSI, RMAT) +

+

+
GIVEN: +
+
+ + + + + + + + + + + + + + + + + +
ORDERC*(*)specifies about which axes the rotations occur
PHIR1st rotation (radians)
THETAR2nd rotation (radians)
PSIR3rd rotation (radians)
+

+
RETURNED: +
+
+ + + + + +
RMATR(3,3)rotation matrix
+

+
NOTES: +
+
1. +
A rotation is positive when the reference frame rotates +anticlockwise as seen looking towards the origin from the +positive region of the specified axis. +
2. +
The characters of ORDER define which axes the three successive + rotations are about. A typical value is `ZXZ', indicating that + RMAT is to become the direction cosine matrix corresponding to + rotations of the reference frame through PHI radians about the + old z-axis, followed by THETA radians about the resulting + x-axis, + then PSI radians about the resulting z-axis. In detail: +
    +
  • The axis names can be any of the following, in any order or + combination: X, Y, Z, uppercase or lowercase, 1, 2, 3. Normal + axis labelling/numbering conventions apply; + the xyz ($\equiv123$) triad is right-handed. Thus, the `ZXZ' example given above + could be written `zxz' or `313' (or even `ZxZ' or `3xZ'). +
  • ORDER is terminated by length or by the first unrecognized + character. +
  • Fewer than three rotations are acceptable, in which case + the later angle arguments are ignored. +
+
3. +
Zero rotations produces a unit RMAT. +
+
+ +next + +up + +previous +
+ Next: SLA_EVP - Earth Position & Velocity +
+Up: SUBPROGRAM SPECIFICATIONS +
+ Previous: SLA_ETRMS - E-terms of Aberration +

+

+

+SLALIB --- Positional Astronomy Library
Starlink User Note 67
P. T. Wallace
12 October 1999
E-mail:ptw@star.rl.ac.uk +
+ + -- cgit