I also added support for quaternions to Factor's math library. Quaternions are useful for certain geometrical calculations; a 3-dimensional rotation around an axis can be represented as multiplication by a quaternion.
Quaternions are represented as pairs of real numbers. Literal syntax is
Q{ a b c d }Q, where a, b, c and d are real numbers.Many quaternion operations can be done using Factor's existing vector algebra words; this follows from the mathematical fact that the quaternions are a 2-dimensional vector space over the complex numbers:
Addition:
v+Subtraction:
v-Negation:
vnegNorm:
normMultiplication by a complex number on the left:
n*vA few new words are also needed:
Convert complex number to quaternion:
c>nMultiply by a complex number on the right:
q*nQuaternion multiplication:
q*Quaternion division:
q/Quaternion conjugate:
qconjugate
1 comment:
Hi, this is off topic but your email address bounced so I found you here.
I was hoping to ask a quick question about your jEdit FTP plugin- namely in what format does the plugin expect the private key when connecting to an SFTP server?
I use a 1024-bit SSH-2 RSA key, as generated by puttygen as a .ppk file, and get the following error - Invalid Private Key File "The key format is not a supported format."
I’m running:
FTP plugin v0.7.3
jEdit v4.2
Java 2 v1.4.2_03
PuTTYgen 0.58
Windows XP Pro SP2
Any advice much appreciated. Many thanks for the plugin :)
cheers, Dave
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