Rank: 398 based on 167 downloads (last 30 days) and 3 files submitted
Personal Profile:

I'm an aerospace systems engineer in the Washington, D.C. region. I have a B.S. and an M.S. in Aerospace Engineering from NCSU, and I've been using Matlab in both work and school since 2004. I'm almost considering using it to do my taxes.

Professional Interests:
Aerospace, GN&C, trajectory analysis, orbit dynamics

 

Watch this Author's files

 

Files Posted by John View all
  • 1 - 3 of
  • 3
Updated   File Tags Downloads
(last 30 days) 		Comments Rating
01 Dec 2011 Screenshot Newton-Raphson Iterative Solver for Systems of Equations An N-R iterative root-finder for systems of N equations and N unknowns. Author: John Fuller newton, raphson, iterative, solver, systems of equations, root 37 2
  • 2.0
2.0 | 1 rating
05 Jan 2011 Function to Convert between DCM, Euler angles, Quaternions, and Euler vectors Function to convert rotation data between 4 types: DCM, Euler Angles, Quaternions, and Euler Param. Author: John Fuller aerospace, 3d, euler angle, rotation, direction cosines, coordinate rotation 82 20
  • 4.44444
4.4 | 9 ratings
18 May 2010 Screenshot Euler angle, DCM, Quaternion, and Euler Vector Conversion/Teaching GUI A GUI that helps users learn how Euler angles and other rotational data relate to one another. Author: John Fuller quaternion, euler angles, dcm, aerospace, euler, gui 48 0
  • 4.0
4.0 | 1 rating
Comments and Ratings by John View all
  • 1 - 5 of
  • 9
Updated File Comments Rating
20 Oct 2011 Newton-Raphson Iterative Solver for Systems of Equations An N-R iterative root-finder for systems of N equations and N unknowns. Author: John Fuller

No humor with this one :)
18 Jul 2011 gmail a reasonably secure wrapper for sendmail that configures, and deletes, settings for gmail servers Author: Naor Movshovitz

Like other functions of similar purpose I've found, the following error message comes up:

Could not connect to SMTP host: smtp.gmail.com, port: 25;
Connection refused: connect

I found this by removing the clc from this function. I'm assuming Gmail has put in some changes that make these no longer functional.
05 Jan 2011 Function to Convert between DCM, Euler angles, Quaternions, and Euler vectors Function to convert rotation data between 4 types: DCM, Euler Angles, Quaternions, and Euler Param. Author: John Fuller

Alright, I don't really have the time to go over semantics in the help text of my code. I can agree that the following block

% DCM - 3x3xN multidimensional matrix which pre-multiplies a coordinate
% frame column vector to rotate it to the desired new frame.

might be better as

% DCM - 3x3xN multidimensional matrix which pre-multiplies a coordinate
% frame column vector to calculate its coordinates in the desired
% new frame.

But the fact still remains that the input DCM data remains the same. I wouldn't say it is highly misleading, but that it also can't be expected to teach every user the nuances of rotation linear algebra as you have illustrated.

The code uses input and output in an accepted convention that 'most' serious users in my industry follow and understand, and it stands simply as that. As with all Matlab FEX code it is very important that the user vets code cautiously before use and knows what goes in and out by external testing.

I will update the commenting above, but I'm not pursuing further modifications to SpinCalc because I believe it is well-accepted, heavily tested, and straightforward as it is. If you don't like that, rate it badly and don't use it.

Thanks,
John
02 Jan 2011 Function to Convert between DCM, Euler angles, Quaternions, and Euler vectors Function to convert rotation data between 4 types: DCM, Euler Angles, Quaternions, and Euler Param. Author: John Fuller

Another note, if you take a look at my other submission called SpinCalcVis it will give a good idea of how input/output is processed by SpinCalc as it is all based on the same parent code.

http://www.mathworks.com/matlabcentral/fileexchange/27653-euler-angle-dcm-quaternion-and-euler-vector-conversionteaching-gui

Thanks,
John
02 Jan 2011 Function to Convert between DCM, Euler angles, Quaternions, and Euler vectors Function to convert rotation data between 4 types: DCM, Euler Angles, Quaternions, and Euler Param. Author: John Fuller

Paolo,
The convention used by SpinCalc is the standard convention where matrix R pre-multiplies the column vector, or R*v. The "by" in the help section could be a bit ambiguous. I can change that when I have the master file back in front of me.

The reason for the inconsistency you are seeing deals with the fact that the R matrix format used in SpinCalc is for the DCM which rotates the coordinate frame about the vector, not the vector about the coordinate frame. Thus, the Euler vector solution corresponds to the vector about which to rotate the frame and by how much.

Your matrix to rotate [1;0;0] 90 degrees about Z is equivalent to rotating the frame -90 about Z, or +90 about -Z. All data input and output for SpinCalc corresponds to rotation of the frame.
Comments and Ratings on John's Files View all
  • 1 - 5 of
  • 27
Updated File Comment by Comments Rating
17 Nov 2011 Function to Convert between DCM, Euler angles, Quaternions, and Euler vectors Function to convert rotation data between 4 types: DCM, Euler Angles, Quaternions, and Euler Param. Author: John Fuller QIU, zhaopeng
20 Oct 2011 Newton-Raphson Iterative Solver for Systems of Equations An N-R iterative root-finder for systems of N equations and N unknowns. Author: John Fuller Fuller, John

No humor with this one :)
12 Oct 2011 Newton-Raphson Iterative Solver for Systems of Equations An N-R iterative root-finder for systems of N equations and N unknowns. Author: John Fuller Knyazev, Andrew

Incomplete description. The function is hard-coded for no more than 8 equations. Quoting the code: "Holy crap! More than 8 equations to solve??"
10 Oct 2011 Function to Convert between DCM, Euler angles, Quaternions, and Euler vectors Function to convert rotation data between 4 types: DCM, Euler Angles, Quaternions, and Euler Param. Author: John Fuller Koppen, Paul

Thanks for the code, it works great.

Funny fact: the rotation matrix returned by the procrustes function in the Statistics Toolbox is quite often not orthogonal to eps.
08 Sep 2011 Euler angle, DCM, Quaternion, and Euler Vector Conversion/Teaching GUI A GUI that helps users learn how Euler angles and other rotational data relate to one another. Author: John Fuller Völker, Michael
Top Tags Applied by John
  • 1 - 5 of
  • 21
aerospace, dcm, quaternion, rotation, 3d
Files Tagged by John View all
  • 1 - 3 of
  • 3
Updated   File Tags Downloads
(last 30 days) 		Comments Rating
01 Dec 2011 Screenshot Newton-Raphson Iterative Solver for Systems of Equations An N-R iterative root-finder for systems of N equations and N unknowns. Author: John Fuller newton, raphson, iterative, solver, systems of equations, root 37 2
  • 2.0
2.0 | 1 rating
05 Jan 2011 Function to Convert between DCM, Euler angles, Quaternions, and Euler vectors Function to convert rotation data between 4 types: DCM, Euler Angles, Quaternions, and Euler Param. Author: John Fuller aerospace, 3d, euler angle, rotation, direction cosines, coordinate rotation 82 20
  • 4.44444
4.4 | 9 ratings
18 May 2010 Screenshot Euler angle, DCM, Quaternion, and Euler Vector Conversion/Teaching GUI A GUI that helps users learn how Euler angles and other rotational data relate to one another. Author: John Fuller quaternion, euler angles, dcm, aerospace, euler, gui 48 0
  • 4.0
4.0 | 1 rating

Contact us at files@mathworks.com