Cody

John D'Errico

289
Rank
5
Badges
1370
Score
E-mail
Company/University Retired
Personal Profile

Mainly retired from Eastman Kodak. (Of course, Kodak itself is now semi-retired. I don't think I had any influence in that.) I still write MATLAB code as I find something interesting, and I do attempt to write new tools to put on the File Exchange when I think I can make a contribution.

However, I DON'T answer direct e-mail questions, and I do NOT do homework. In general, your homework is YOUR problem, not mine. Please do NOT e-mail me with your homework problems or student projects. If I was willing to answer your questions, I would very rapidly become overwhelmed, because one question is never just one simple question.

When I'm not doing something with MATLAB, you might find me playing bridge, either in the club or online on BBO.

Professional Interests: MATLAB, numerical analysis, mathematical modeling

Avocational interests: Bridge, woodworking, woodturning

Professional Interests

Bridge, MATLAB, numerical analysis, mathematical modeling

Activities

1 – 50 of 212

John D'Errico submitted Solution 970546 to Problem 164. Right and wrong

on 15 Sep 2016 at 14:51

John D'Errico submitted Solution 970545 to Problem 164. Right and wrong

on 15 Sep 2016 at 14:50

John D'Errico submitted a Comment to Problem 42935. Sums of cubes and squares of sums

I did not originally look to see exactly how far one could go. It looks like, IF one is careful in the important expression, you should be able to get to 3329020. I'd expect that the code I'd write that would solve this to go as far as 3329020 would employ an initial test to know if n is even or odd, changing the expression I'd write depending on the parity of n. Of course that branch would also increase the complexity, so raising the Cody score.

on 29 Aug 2016

John D'Errico received Speed Demon badge for Solution 944700

on 28 Aug 2016

John D'Errico submitted a Comment to Problem 240. Project Euler: Problem 6, Natural numbers, squares and sums.

A problem where one must be at least a little careful about floating point arithmetic. It might have been interesting if one of the test cases were x=1e5 or larger. Even more interesting if the execution time were a factor in the "score". These factors might impact how the problem would be best solved.

on 28 Aug 2016

John D'Errico submitted a Comment to Problem 625. Determine Whether an array is empty

Terrible test set.

on 28 Aug 2016

John D'Errico submitted Solution 940778 to Problem 76. De-dupe

on 23 Aug 2016

John D'Errico submitted a Comment to Problem 174. Roll the Dice!

The first test case for this problem is flat out statistically terrible! In fact, it is quite easy for that assertion to fail on a well defined set of uniform dice! So if you submitted a "valid" solution to this trivial problem, and it failed, then re-submit it. It may well succeed the second time you try, with no change to your function at all.

on 23 Aug 2016

1 – 50 of 212