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Numeric matrix manipulation: Cheat sheet (sebastianraschka.com)
53 points by jonbaer on July 19, 2014 | hide | past | favorite | 9 comments


You know what would be interesting? A cheat sheet that says "this matrix operation helps you solve this problem". Linear algebra (the immediately encompassing field here) is a goldmine of practical solutions to problems people actually pay others to solve, so a few pointers could be immensely useful.


You might be interested in this book:

http://codingthematrix.com/

Also, Strang's 16.02 lectures on Youtube were incredibly useful for me, far more so than any book.


I've been watching his lectures from 18.06 this weekend (from here: http://ocw.mit.edu/courses/mathematics/18-06-linear-algebra-...).

I just googled and didn't find any reference to 16.02

I started using Axler's Linear Algebra Done Right. I found it _great_ when I was in the flow and could do the simple proofs in the exercises or 'as you should verify', and frustrating when I was stuck on the same page for an hour and needed to ask a friend for help. The reason I'm watching Strang's lectures now is that I paused my study for a while, and want a refresher before I pick Axler where I left off. I can't bear the thought of re-starting Axler from the beginning, but I know I can't just pick up where I left off :(

I'll take a look at coding the matrix.


Axler's book is much more of a pure math book, in the spirit of an abstract algebra or analysis book. Strang's book is more applied, applications oriented, more mechanical in nature. Both approaches have their place, Strang is more suitable for engineers. I find Axler far more elegant, and his arguments generalize much more readily to infinite dimensions. I would recommend Axler for budding mathematicians and people wanting to study functional analysis and operator theory later on.


18.06! Not 16.02. Sorry!


Phew! I thought for a moment I'd spent my weekend watching his second-best lecture series!


Strang's book is superb. I'm switching back and forth between his videos and book. And I prefer the latter for content and using my hours efficiently. I prefer the videos for his laid-back style of delivering the lecture.


I don't really see how this is a cheat sheet.

What is a cheat is the benchmark graph the author has taken from the Julia site, which lists languages in decreasing order of benchmark performance - except Julia, which is listed before Fortran, despite being slower at everything except parsing integers.


Scroll down to the bottom of the article and you'll see the cheat sheet:

http://sebastianraschka.com/Articles/2014_matrix_cheatsheet....

(click on the image)

Also fyi, the author could have also included syntax for Mathematica and WolframAlpha. I think he was focusing on free software but WolframAlpha is free for modest usage as alternative to the monthly paid subscription plan.

http://www.wolframalpha.com/examples/Matrices.html

http://reference.wolfram.com/language/howto/CreateAMatrix.ht...




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