computation of matrix Q

[huiwenzhang]

Hi, According to the formula given in the blog, the code below https://github.com/zm0612/Minimum-Snap/blob/0a31cc9c723e4fc8af81835277a1cbc342160788/src/waypoint_trajectory_generator/src/trajectory_generator.cpp#L129-L132 should be

 sub_Q(i, l) = (Factorial(p_order - i) / Factorial(p_order - order - i)) *
                              (Factorial(p_order - l) / Factorial(p_order - order - l)) /
                              (p_order - i + p_order - l - 2 * order + 1) *
                              pow(Time(k), p_order - i + p_order - l - 2 * order + 1);

The integral of term $t^{(p{order} - i - order + p{order} - l -order)}$ gives p_order - i + p_order - l - 2 * order + 1. I modified the code to my version, however it fails to give a solution, I guess somewhere else wrong with this modification. Please have a look.

[zm0612]

Hi, thank you very much for your suggestion. But when I compare the code you gave, it looks like you just removed the parentheses, but in fact their operations are still the same.

[huiwenzhang]

Hi, thank you very much for your suggestion. But when I compare the code you gave, it looks like you just removed the parentheses, but in fact their operations are still the same.

different, the symbol '1' and 'l' are very confusion, here 'l' stands for column index. my answer is $p{order} - i + p{order} - l - 2order + 1$, you code is $p{order} - i + p{order} - l - 2order + 2$

[zm0612]

I found the difference, I'll take the time to test it, thank you very much.

[HongweiSunny]

so this question has been fixed?