Hacker News: sika_grr

New comment by sika_grr in "Fast Inverse Square Root"

sika_grr — Tue, 03 Nov 2020 07:11:51 +0000

You mention the wiki page is badly written, and I have the same feeling whenever I read about anything mathematics related on it. But... it's written by volunteers, so I'll take what I can get. Since you obviously have the talent for explaining things, do you think the wiki page could be edited and improved for clarity?

New comment by sika_grr in "Show HN: This Word Does Not Exist"

sika_grr — Thu, 14 May 2020 08:34:45 +0000

wow, just wow

unsubscriber: a system of telephone bills and their fees which can be charged only to subscribers "every item is charged with the unsubscriber"

New comment by sika_grr in "Investigating the Performance Overhead of C++ Exceptions"

sika_grr — Wed, 12 Feb 2020 12:49:58 +0000

There is a difference between preventing a program crash and handling errors. Please don't use catch-all-exceptions clause for either, especially not in hospital machines.

The difference between writing if (status != SUCCESS) and catch (Exception) is that the former will allow the program to actually crash when it should (see panic in Rust). You should not be able to recover from OutOfMemory or GammaRayFlippedABit errors (use ECC memory to prevent that). You should restart the process (or the entire machine) because you can't hope the developer was wise enough to destroy and recreate appropriate amount of state.

The additional problem with exceptions in Java and C# is that many times you don't care about failure of some operations, but the language practically forces you to write catch-all statement to prevent a program crash, so you end up accidentally catching unrecoverable errors.

New comment by sika_grr in "Investigating the Performance Overhead of C++ Exceptions"

sika_grr — Wed, 12 Feb 2020 09:46:40 +0000

I disagree with both points, in fact with every statement you made. Correctness can be achieved without use of exceptions (whether this is easier or harder to do is up for debate). Next, in some cases correctness may be sacrificed for performance reasons (e.g. solving a traveling salesman problem). I find it easier to properly handle unexpected error codes than unexpected exceptions. C++ has other strong sides beside performance. Java/C# often throw exceptions in very non-exceptional cases (e.g. .Net's File.Delete method).

New comment by sika_grr in "“Username or password is incorrect” is bullshit"

sika_grr — Fri, 22 Dec 2017 10:56:34 +0000

> Even if reCAPTCHA was perfect, a hacker could manually validate their usernames of interest by trying to sign up, then automate an attack on the sign in page.

Why is imperfect reCAPTCHA worthless? Do sign up pages even allow brute forcing of usernames (once validated)?

Is he suggesting to fix sign up pages, or to allow brute forcing usernames on login?

His writing style is dramatic, but the arguments are very weak.

New comment by sika_grr in "Inadequacy and Modesty"

sika_grr — Mon, 30 Oct 2017 08:50:56 +0000

If this is one of his worst, I must read the rest. You are unsatisfied with an essay that is merely of correct reasoning, can you recommend some even better reading material than this?

New comment by sika_grr in "The rise of super-voting shares has given founders the ultimate job security"

sika_grr — Fri, 07 Apr 2017 07:03:01 +0000

Does nobody on Hacker News watch Silicon Valley? Or are references in comments frowned upon?

New comment by sika_grr in "Vitter's reservoir sampling algorithm D: randomly selecting unique items"

sika_grr — Mon, 04 Apr 2016 10:03:32 +0000

I only see an O(n) algorithm there, there is no O(k). Am I missing something?

New comment by sika_grr in "Why Yahoo Couldn’t Adapt to the Smartphone Era"

sika_grr — Wed, 10 Feb 2016 14:43:37 +0000

http://www.toothycat.net/~hologram/Turing/HowItWorks.html

New comment by sika_grr in "The SRGB Learning Curve"

sika_grr — Thu, 03 Dec 2015 08:23:28 +0000

Yea, I guess that also explains why gradients don't look that smooth.

New comment by sika_grr in "The SRGB Learning Curve"

sika_grr — Wed, 02 Dec 2015 15:33:37 +0000

Can anyone explain the gradient merging example? If we sum an image in which luminosity is linearly rising from left to right with the image in which the luminosity is linearly rising from top to bottom, then the result should have constant luminosity across bottom left - top right diagonal. So we shouldn't see a circle effect in the top left corner, but rather a rotation of first gradient by +45 degrees. Or are the gradients not linear in luminosity? Or are you guys not seeing the circle effect? It does looks quite different on my other monitor, but I can still clearly see a circle instead of topleft-bottomright linear drop in luminosity on the left example.

New comment by sika_grr in "Grepping logs is still terrible"

sika_grr — Thu, 07 May 2015 12:01:53 +0000

Of course you need to log some data in textual format for emergencies, but if you had a tool that indexes events on timestamps, servers, monitorees, severity and event type, while severely reducing the storage required, you would be able to log much more data, and find problems faster. Arguing binary vs text logs is like arguing serial port vs USB on some industrial systems.

New comment by sika_grr in "Show HN: MagicEye.js – Generate Magic Eye in Your Browser"

sika_grr — Mon, 01 Dec 2014 09:45:22 +0000

Nevermind, I managed to squint enough to get the letters to combine into a perfect image. It should not be possible to get more than 1 correct 3D image, the period of the background should be increased.

New comment by sika_grr in "Show HN: MagicEye.js – Generate Magic Eye in Your Browser"

sika_grr — Mon, 01 Dec 2014 09:40:07 +0000

Wait, did it get your name right? It's kinda buggy for me, it draws every letter twice for me (twice in 3D, of course it has to draw it twice in 2D).

New comment by sika_grr in "The Unreasonable Effectiveness of C (2013)"

sika_grr — Thu, 27 Nov 2014 22:03:33 +0000

Yea, change a certain .h file and you can go get a cup of coffee while waiting for the build to end. This can't ever happen with Java/C#.

New comment by sika_grr in "Slightly Skeptical View on Sorting Algorithms"

sika_grr — Tue, 14 Oct 2014 14:38:43 +0000

No. For radix sort this constant factor is quite low, so it outperforms std::sort in most cases.

Try sorting a million integers, my results are: std::sort: 60 ms; radix-sort (LSB, hand coded, less than 20 lines): 11 ms. It gets even better when you mix MSB with LSB for better locality.

No, there are no problems with doubles or negative integers. For sizeof(key_value)<=16 B (8 for key, 8 for pointer), radix is the best sort on desktop computers.

New comment by sika_grr in "Slightly Skeptical View on Sorting Algorithms"

sika_grr — Tue, 14 Oct 2014 10:44:14 +0000

Please note that radix sort is easy to implement to work correctly with doubles, Table 1 is misleading.