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Dot vs cross



I just write this thread because there still have questions about dot and cross products here, and I remeber that I wrote some other threads about them (links at the end).

Some reminders about differences between cross product and dot product.

The first one is important, the cross product creates a vector, the dot product creates a number !

Graphically, the dot can be represented like this :

The same way for the cross :


The problem about the cross product with PC-DMIS, is that the result is always a unit vector (the result is divided by its own length).
So you can't use it directly to calculate angles or distances.

A little more about it on those threads, old or not, giving explanations or examples...
https://www.pcdmisforum.com/forum/pc...xamples-of-use
https://www.pcdmisforum.com/forum/pc...sing-variables
https://www.pcdmisforum.com/forum/pc...of-dot-product
https://www.pcdmisforum.com/forum/pc...-about-vectors
https://www.pcdmisforum.com/forum/pc...on-from-points
https://www.pcdmisforum.com/forum/pc...point-to-plane
Parents
  • : I'm sorry, I'm not sure to understand the first question...Disappointed If you want an accurate result, you have to use the max decimal places.
    If you calculate a lonfg vector with only 3 decimal places, I'm not sure that the result is good (I will check it, asap Slight smile)
    For the second, I remember now, it has been "reported" long time before I registered on the forum. As usual, the answer was : " it works as it's concepted"...
Reply
  • : I'm sorry, I'm not sure to understand the first question...Disappointed If you want an accurate result, you have to use the max decimal places.
    If you calculate a lonfg vector with only 3 decimal places, I'm not sure that the result is good (I will check it, asap Slight smile)
    For the second, I remember now, it has been "reported" long time before I registered on the forum. As usual, the answer was : " it works as it's concepted"...
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