Home Numerical Excel Tutorial Microscopic Pedestrian Simulation Kardi Teknomo's Tutorial Micro-PedSim Free Download Personal Development Handbook

 Research Publications Tutorials Resume Resources Contact

## Tutorial Feedback

We have 10 comments on this tutorial

> (date: )
By
rate up: 2 rate down: 4 last rated date: 2014-04-22

Answer > comment on cross-product page (date: 2011-01-27)
By Kardi
Thanks Mark for the report. The vector n is the cross product result explained in the figure right below the properties. To make it clearer, I fixed the equations that you have pointed out. Thanks also for the tips on Sphinx.
rate up: 221 rate down: 205 last rated date: 2014-04-24

Error Report > one other remark (date: 2011-01-27)
By Mark Edgington
Page: http://people.revoledu.com/kardi/tutorial/LinearAlgebra/VectorTripleCrossProduct.html Properties: \"Similarly, ...\" (and the preceding property) -- use either (a^T c) or (a . c), but not (a^T . c). Also, have you considered converting this website to use Sphinx? It makes fantastic websites, and allows you to write your math inline in the rst source files as LaTeX formulas. -- http://sphinx.pocoo.org/
rate up: 234 rate down: 178 last rated date: 2014-04-20

Error Report > comment on cross-product page (date: 2011-01-27)
By Mark Edgington
On http://people.revoledu.com/kardi/tutorial/LinearAlgebra/VectorCrossProduct.html, the equation in the property starting \"The magnitude of vector cross...\" is missing norm-bars. In other words, a x b => ||a x b||. There is also a mysterious \'m\' or \'n\' in the RHS of the equation.
rate up: 232 rate down: 188 last rated date: 2014-04-24

Answer > Moore Penrose inverse (date: 2011-04-16)
By Mimeides
I use the SVD decomposition in order to inverse my matrix but it dont work. If i put my matrix in your web site ... it works ... How do you do to inverse a matyrix with the svd decomposition... Thanks a Lot... Your site is a beatiful land !!!
rate up: 244 rate down: 210 last rated date: 2014-04-20

Question > SQUARE ROOT OF SYMMETRIC MATRICES (date: 2012-04-09)
By DONALD GILES
I AM DOING SOME RESEARCH IN COMBINATORICS. IF I HAVE A 7BY7 MATRIX WITH 3 DOWN THE MAIN DIAGONAL AND 1 EVERYWHERE ELSE. THE SQUARE ROOT WILL BE A 7BY7 SYMMETRIC MATRIX WITH THREE 1'S IN EACH ROW AND COLUMN.ALSO THE DIRECT PRODUCT OF EACH PAIR OF ROWS AND EACH PAIROF COLUMNS WILL EQUAL 1.IF I CAN SEE HOW TO DO THIS SIMPLEST OF ALL EXAMPLES THEN I SHOULD BE ABLE TO WORK ON AN 81 BY 81 MATRIX WITH 16 DOWN THE MAIN DIAGONAL AND 3 EVERWHERE ELSE.I WOULD BE LOOKING FOR THE SQUARE ROOT OF THIS MATRIX WHICH WOULD HAVE SIXTEEN 1'S IN EACH ROW AND COLUMN. ALSO THE DIRECT PRODUCT OF EACH PAIR OF ROWS AND COLUMNS WOULD BE THREE.THIS MATRIX WOULD ALSO HAVE TO SYMMETRIC. NOTE;WE NEED A=ATRANSPOSE TO MAKE THIS WORK.
rate up: 142 rate down: 130 last rated date: 2014-04-23

Thank you > Vector Algebral (date: 2012-06-28)
By Yusuf Faidat
I'm really happy and greatful because this site has help improve my maths
rate up: 149 rate down: 138 last rated date: 2014-04-24

Error Report > RREF Matrix (date: 2012-08-30)
By Abdul Hakim
I tried this matrix: 2,1,4,1,0,0; 3,5,1,0,1,0; 2,0,6,0,0,1; 0,0,0,0,0,0; 0,0,0,0,0,0; 0,0,0,0,0,0; mistake happens at the end: Add: R(2) = R(2) + 1_3/7 * R(3) : 1,0,0,7_1/2,-1_1/2,-4_3/4; 0,1,0,-3,1,2_1/2; --> mistake at (-3) supposed to be (-4) 0,0,1,-2_1/2,1/2,1_3/4; 0,0,0,0,0,0; 0,0,0,0,0,0; 0,0,0,0,0,0;
rate up: 143 rate down: 139 last rated date: 2014-04-20

Thank you > SVD (date: 2013-05-25)
By Michael Stanko
Very excellent way to explain SVD. Short, precise, enlightening. Within a couple of minutes I recalculated all the steps in R. Now I undertand the relation between SVD and Eigen. Kind regards, Michael PS: I am a novice to applied maths and statistics / autodidact
rate up: 57 rate down: 62 last rated date: 2014-04-21

Thank you > THIS IS GR8 (date: 2014-02-26)
By economia
THIS IS GR8
rate up: 18 rate down: 12 last rated date: 2014-04-22