Doing Symbolic Math with SymPy

Post by creata » Fri, Jan 08, 2021, 5:10 PM UTC

hakuseki wrote: post #39

leephillips wrote: post #29

Earlier quoted context omitted.

What strikes me as weird about this is that our intent is to do something to the array of strings, so we are looking for a function that takes this array and transforms it into something else. But we are obligated to invert our intuition here, and write this as if we are doing something to the punctuation that we want to insert between the array elements. It’s backwards, and causes us (me, anyway) to keep forgetting…

> It could even be written in a way where the order of arguments didn’t matter Well, 'hello'.join(', ') does not produce the same output as ', '.join('hello'), so the order of the arguments does matter.

Post by leephillips » Fri, Jan 08, 2021, 5:13 PM UTC

hakuseki wrote: post #39

leephillips wrote: post #29

Earlier quoted context omitted.

What strikes me as weird about this is that our intent is to do something to the array of strings, so we are looking for a function that takes this array and transforms it into something else. But we are obligated to invert our intuition here, and write this as if we are doing something to the punctuation that we want to insert between the array elements. It’s backwards, and causes us (me, anyway) to keep forgetting…

> It could even be written in a way where the order of arguments didn’t matter Well, 'hello'.join(', ') does not produce the same output as ', '.join('hello'), so the order of the arguments does matter.

Post by Koshkin » Fri, Jan 08, 2021, 5:38 PM UTC

creata wrote: post #31

snakeboy wrote: post #30

Earlier quoted context omitted.

Exactly, it has been refined over millennia.

Right, and it's important to remember that mathematics is sharply optimized for human understanding, whereas programming languages strike a careful compromise between human understanding and efficient execution by machines. I don't think anyone could seriously argue that programming languages are "more expressive" than mathematical notation, which has the powers of ambiguity and hand-drawn graphics.

Post by leephillips » Fri, Jan 08, 2021, 6:03 PM UTC

eli_gottlieb wrote: post #46

leephillips wrote: post #18

Earlier quoted context omitted.

This is problem I have with Python in general; that even if you prefer to use it in a functional style, most libraries are written by real Python programmers, and using them will force you to grapple with the object-oriented inversion of common sense ( https://lee-phillips.org/pythonhate/ ). My favorite example is: ','.join(['a', 'b'])

You tried Coconut? http://coconut-lang.org/

Post by mehrdadn » Fri, Jan 08, 2021, 7:07 PM UTC

BeetleB wrote: post #48

mehrdadn wrote: post #16

The trouble with SymPy is it's, well, buggy. I tried it a few years ago, and as soon as I got serious, I quite quickly ran into problems that I reported, some of which I now see they apparently still haven't gotten around to addressing. [1] [2] Symbolic math is hard ; they have my sympathies. I don't think I could do better. But as long as bugs like these exist, it's going to be hard to convince people to switch away…

Yikes those are bad. As a non-user interested in it, I must confess that seeing those issues (especially the 2nd one) makes me not want to use it! I do get that it is a hard problem, but I would then recommend they not have an option for "real" if they can't get it right. Users will expect it to work (unless the docs point out it is unreliable).