Re: Rotate a 3D vector

Back to the trenches with me. I'm starting with a 2d space till i can wrap my head around it. The code and examples i am finding are not matching up in 3d space. Here's my closest attempt which still is wrong. Can anyone help?

# 2 points on a plane
my $x = 2;
my $y = 1;
#yang is the y-angle 0-360 i want to rotate by
my $yang = 45;
#convert yang to radians
$yang = 3.14159265358979*$yang/180;
#rad is the radius of my sphere
my $rad = sqrt($x**2 + $y**2);
my $x = cos($yang)*$rad;
my $y = sin($yang)*$rad;
print "x=$x\ny=$y\n";
[download]

Advice appreciated.

jtrue

Comment on Re: Rotate a 3D vector Download Code

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Re^2: Rotate a 3D vector by johnnywang (Priest) on Oct 18, 2004 at 03:57 UTC
Just a little change, the formula was not correct (as I pointed out in my previous post in this thread) `# 2 points on a plane my $x = 2; my $y = 1; #yang is the y-angle 0-360 i want to rotate by my $yang = 45; #convert yang to radians $yang = 3.14159265358979$yang/180; my $xnew = cos($yang)$x - sin($yang)y; my $ynew = sin($yang)$x + cos($yang)*y; print "x=$xnew, y=$ynew\n";` [download]	[reply] [d/l]

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Re^2: Rotate a 3D vector
by johnnywang (Priest) on Oct 18, 2004 at 03:57 UTC

# 2 points on a plane
my $x = 2;
my $y = 1;
#yang is the y-angle 0-360 i want to rotate by
my $yang = 45;
#convert yang to radians
$yang = 3.14159265358979*$yang/180;
my $xnew = cos($yang)*$x - sin($yang)*y;
my $ynew = sin($yang)*$x + cos($yang)*y;
print "x=$xnew, y=$ynew\n";
[download]

[reply]
[d/l]