ggruschow's comments

ggruschow | 3 years ago | on: Extracting WhatsApp Messages from an iOS Backup

Not as of 2 months ago. It took days of crashing or hanging programs to get the photos off my wife's iPhone. I tried everything mentioned including Image Capture on a new MacBook, and the problems were at least as bad for me. I had to change the sleep settings on every device involved to multiple hours because a 30 minute hang was on the good side. In the end, what ended up working best was a full backup of the phone to a PC with iTunes, and extracting the photos out of the backup with iMazing.

For perspective.. I remember downloading and installing Linux off floppies. That sucked too, especially with bad disks or download errors, but it was less frustrating than this.

It seems like they don't improve it because iCloud seems like it works smoothly, and they get an on-going profit stream out of it. The process was so brutal I almost broke down and paid for a ton of iCloud storage.. but didn't because getting lots of photos out of iCloud is also painful.

ggruschow | 14 years ago | on: Nasdaq ITCH

Some things to think about:

  - 50mb is >> total cache on most systems you'll use.
  - This is far from the only function you need to optimize.
  --> The best performing algorithm in a micro-benchmark can be sub-optimal in real use.

  - You've got a fixed-for-the-day list of <10k <9 letter unique upper-case strings
  - The bulk of them you'll process are <= 4 letters (CMCSA/CMCSK be damned).
  - The median is 3 and the mean is <3.6.
  - The symbols aren't anywhere close to uniformly active
  --> Benchmark with a typical data stream, not a uniformly distributed one.

  - You're likely not even considering trading most of them.

  - How much better is your algorithm than the obvious binary-search?
  - Or worse -- plain'ol front-to-back linear search?
  - Are you sure you understand 100% of how the computer works?
    --> Yes? Mail a check to Goldman and find a better line of work.
    --> No? Test it with a quick benchmark.

  - Is binary search cache friendly?
  - Why not? Plot out the memory accesses if need be.

  - What's wrong with taking a linear-interpolated guess?
  - Is that cache friendly? .. or could it be?
  - When your guess misses, what's that cost?
  - Can you think of a cheap modification to lower that cost?
  - Is the distribution really linear?

  - What's wrong with a "perfect hash function"?
  - Does it need to be perfect?
Incidentally, hardware wins at this function. You can just generate logic to do all the if symbol == "XYZ": return 3's in parallel.

ggruschow | 14 years ago | on: Building a pure CSS 3D City

Panning would work fine since the objects in this projection don't change anything but position with panning. Spinning would only work in 90 degree increments, but that's fine for many, maybe most cases you'd be doing this. Most isometric-ish projection systems I recall seeing don't spin / change perspective. I'd imagine that's because it's disturbing to look at since things don't get smaller as they get farther away. For whatever reason the static version doesn't induce the same reaction.

ggruschow | 14 years ago | on: Building a pure CSS 3D City

You could skip all the CSS transformation stuff and just serve the browser the images in the orientation you want them. In this projection and buildings-of-cubes, there's only 2 perspectives for a wall and 1 for ground/roofs.

ggruschow | 15 years ago | on: IPhone 4 About to Be Flickr's Top Camera

Smartphones are replacing standalone cameras, but the analysis in the article is busted. Popular camera models are constantly being replaced with newer shinier models, so of course every model trends down a little while after release. It'd probably be a lot more enlightening to do the analysis grouping usage by family (e.g. Canon G11, G10, G9, etc) once and then doing an age analysis for each family.

ggruschow | 15 years ago | on: Algorithms take control of Wall Street

It's easy to be wrong when it's so hard to make out what's right. Algorithmic traders are unusually secretive about their modes of operation. The primary knowledge dissemination mechanism is via employees moving.

ggruschow | 15 years ago | on: Azul's Pauseless Garbage Collector

To be fair, if you've got a budget that supports a multi-developer team and you fundamentally need their solution, you can afford their prices. They're not insane, and if you just ask they're not opaque.

On the other hand, did you know you can turn off the garbage collector on CPython?

ggruschow | 15 years ago | on: Ask HN: Any high frequency trading hackers

HFT provides liquidity which reduces everyone else's cost and/or exposure to short term risk.

Low-latency trading though costs everyone. Nobody actually needs anything faster than a fill in a blink of an eye. The only people who think they do really need smarter match engines or to stop taking advantage of people

ggruschow | 15 years ago | on: Microsoft furious at $2,000 bounty for open source Kinect drivers

I didn't say it was just a webcam. I said it should cost in the ballpark of 2x of them. Adding a $1 LED with hundreds of little holes in front of it doesn't change that.

Note: I'm not making any statement about the possible awesomeness or lameness of the system. All I'm saying is the parts aren't expensive.

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