Re: Rotation matrix definition

[Farzad Torabi]

I checked and if I am correct , the movements in global CS as

x= -5.1 , y=-6.7 , z = -9.9 , Rx=-0.9, Ry= -1.6 , Rz= -0.4

should give translations of 

x= -2.5712,  y= -12.702, z= 0.98144

I can't verify the rotations, but just want to see if these are correct

the new cs X vector is , as mentioned in the previous email : 

 [-115.830   -16.850   113.400]   

On Thu, Nov 21, 2019 at 2:55 PM Farzad Torabi <address@hidden> wrote:

loading the nurbs package , it seemed to be working. 

ok, let's make the example, the vector X of the new CS is :  [-115.830   -16.850   113.400] in the global CS

I myself used the 

anglex = atan2(norm(cross(a,b)), dot(a,b))

to check the angle between Xglobal and Xnew and it should be 44.7° ( also checked with CAD)

so my next steps could have been finding the angles with all other axes and then form the transformation matrix and multiply it in the old Vecotr

but

instead,  using the proposed formula :

T = vecrot(pi, (vecXnew + [1; 0; 0])/2)

I get 

T =

  -0.66887   0.33401   0.33401   0.00000
   0.33401  -0.66308   0.33692   0.00000
   0.33401   0.33692  -0.66308   0.00000
   0.00000   0.00000   0.00000   1.00000

is it the same result ? meaning : the total transformation matrix ?

On Thu, Nov 21, 2019 at 2:45 PM Nicholas Jankowski <address@hidden> wrote:

I just have one problem : despite having installed the geometry package,  I get the error :  " vecrot is not defined"

Did you load the package before trying to use it? 

>> pkg load geometry

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SeyedFarzad Torabi

Master of Mech. Eng.

Politecnico Di Milano

LinkedIn

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SeyedFarzad Torabi

Master of Mech. Eng.

Politecnico Di Milano

LinkedIn