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I think that perhaps the most interesting part of this article is that it comes from a blog called 'accidentallyquadratic' with more than one entry.

by ouid 10y ago

thunderbong 10y ago
Yes! And posts dealing with quadratic behavior in languages!
jameshart 10y ago
I remember coming across it before when the left-pad incident happened, and marvelling at the fact there were already many entries there then. The problem is now, whenever a new entry on this blog gets linked, I find myself compelled to go back and read all the entries in it again. I can't help thinking that over time, that process is going to become prohibitively slow.
- ouid 10y ago
  It's probable that, as time goes on, the interestingness threshold for linking to a post on the blog will get higher, perhaps even exponentially.
- rikkus 10y ago
  This should be the highest voted comment on hackernews, or we're doing something wrong.
  - ouid 10y ago
    it's pretty elegant.
emfree 10y ago
One of the older posts eloquently discusses why "accidentally quadratic" behavior is both so recurring and so insidious: http://accidentallyquadratic.tumblr.com/post/113840433022/why-accidentally-quadratic http://accidentallyquadratic.tumblr.com/post/113840433022/wh...
- vanderZwan 10y ago
  Raise your hand if you have not only written accidentally quadratic code, but managed to compose said code in such a way that you ended up with something even worse! raises hand Imagine you have a React SPA where users can select a number of items for which they want more information (I can't give more details at this moment). Said information has to be fetched from the server upon selection. I recently discovered that the website would fetch all selected items whenever a new item was selected, including previously selected items, regardless of whether it had already been fetched. So if I start with one selection and build up to n, that is 1 + 2 + .. + n-1 + n = (n²+n)/2[0]. Whoops. To make it worse, I had also somehow had managed to set up my components in such a way that for each fetch being received, React would remount (that's right, re-mount) all of the selected items. Don't ask me how. I'll just say have only been doing web stuff since last year and leave it at that. If we assume a user clicks fast enough to select every item before the fetches are received, that would be the previous equation multiplied by n selections, so.. (n³+n²)/2. Yikes! So yeah... that was stupidly slow. Here's what I did to fix it; obvious but worth spelling out: - only fetch what hasn't been/isn't being fetched - only re-render the component that was updated - don't immediately do the above when the user selects an item; let them make a selection first, then click a "show information" button, then fetch all the needed information in a *single* fetch and render it in a *single* update to the components. [0] https://www.wolframalpha.com/input/?i=sum+one+to+n https://www.wolframalpha.com/input/?i=sum+one+to+n
inopinatus 10y ago
Looking forward to sister blog "Inadvertently Exponential" and the satirical "Maliciously Factorial".
- greenyoda 10y ago
  Many years ago, I got a bug report about a feature in an ex-coworker's code. The complaint was that the program would hang when you added the tenth item in a GUI. It turned out that it didn't really hang, but took a half hour to execute because the algorithm was inadvertently exponential. Further examination of the code revealed that the result of the exponential calculation wasn't even being used. So I didn't have to figure out how to make the algorithm linear - I just removed the useless code.

I think that perhaps the most interesting part of this article is that it comes from a blog called 'accidentallyquadratic' with more than one entry.

by ouid 10y ago

I think that perhaps the most interesting part of this article is that it comes from a blog called 'accidentallyquadratic' with more than one entry.

thunderbong 10y ago

Yes! And posts dealing with quadratic behavior in languages!

jameshart 10y ago

I remember coming across it before when the left-pad incident happened, and marvelling at the fact there were already many entries there then. The problem is now, whenever a new entry on this blog gets linked, I find myself compelled to go back and read all the entries in it again. I can't help thinking that over time, that process is going to become prohibitively slow.

ouid 10y ago
It's probable that, as time goes on, the interestingness threshold for linking to a post on the blog will get higher, perhaps even exponentially.
rikkus 10y ago
This should be the highest voted comment on hackernews, or we're doing something wrong.
- ouid 10y ago
  it's pretty elegant.

emfree 10y ago

One of the older posts eloquently discusses why "accidentally quadratic" behavior is both so recurring and so insidious: http://accidentallyquadratic.tumblr.com/post/113840433022/why-accidentally-quadratic http://accidentallyquadratic.tumblr.com/post/113840433022/wh...

vanderZwan 10y ago
Raise your hand if you have not only written accidentally quadratic code, but managed to compose said code in such a way that you ended up with something even worse! raises hand Imagine you have a React SPA where users can select a number of items for which they want more information (I can't give more details at this moment). Said information has to be fetched from the server upon selection. I recently discovered that the website would fetch all selected items whenever a new item was selected, including previously selected items, regardless of whether it had already been fetched. So if I start with one selection and build up to n, that is 1 + 2 + .. + n-1 + n = (n²+n)/2[0]. Whoops. To make it worse, I had also somehow had managed to set up my components in such a way that for each fetch being received, React would remount (that's right, re-mount) all of the selected items. Don't ask me how. I'll just say have only been doing web stuff since last year and leave it at that. If we assume a user clicks fast enough to select every item before the fetches are received, that would be the previous equation multiplied by n selections, so.. (n³+n²)/2. Yikes! So yeah... that was stupidly slow. Here's what I did to fix it; obvious but worth spelling out: - only fetch what hasn't been/isn't being fetched - only re-render the component that was updated - don't immediately do the above when the user selects an item; let them make a selection first, then click a "show information" button, then fetch all the needed information in a *single* fetch and render it in a *single* update to the components. [0] https://www.wolframalpha.com/input/?i=sum+one+to+n https://www.wolframalpha.com/input/?i=sum+one+to+n

inopinatus 10y ago

Looking forward to sister blog "Inadvertently Exponential" and the satirical "Maliciously Factorial".

greenyoda 10y ago
Many years ago, I got a bug report about a feature in an ex-coworker's code. The complaint was that the program would hang when you added the tenth item in a GUI. It turned out that it didn't really hang, but took a half hour to execute because the algorithm was inadvertently exponential. Further examination of the code revealed that the result of the exponential calculation wasn't even being used. So I didn't have to figure out how to make the algorithm linear - I just removed the useless code.