Show HN: Similar Phone Finder • Hacker News Board

Re: Show HN: Similar Phone Finder

#21

Post by gambiting » Wed, May 06, 2015, 3:26 PM UTC

The name recognition could work better. For "HTC M8" it said it had no results. For "M8" it asked me "which M8?", but had only one option. Also - really? The alternative to HTC M9 is....M8? It's like saying that the alternative to Galaxy S6 is S5, and to S5 is S4. Not very helpful.

Re: Show HN: Similar Phone Finder

#22

Post by [deleted] » Wed, May 06, 2015, 3:26 PM UTC

[deleted]

Re: Show HN: Similar Phone Finder

#23

Post by NDizzle » Wed, May 06, 2015, 3:50 PM UTC

What about the physical dimensions of the devices?

Re: Show HN: Similar Phone Finder

#24

Post by leni536 » Wed, May 06, 2015, 3:56 PM UTC

no_gravity wrote: post #20

leni536 wrote: post #19

Your euclidean distance formula is kind of wrong (at least on the site). The units of each term are incompatible so cannot be added together directly, they all should be normalized with a weight factor. A sensible weight factor would be the inverse of the standard deviation of the specific term. Alternatively you could use the inverse of the covariance matrix as the metric tensor of the properties since there could b…

The values that go into the formula are normalized, but not weighted. So a similar screen size is "worth" as much as a similar weight. If you find examples, where weighted results would perform better, let me know. You can compare the given phone to other phones by clicking them in the list on the right.

Normalized to what? For me normalization or weighting is equivalent. Putting it this way there could be different normalization factors. Examples:

   1. Average value over all phones
   2. Standard deviation of the value over all phones
   3. Minimal noticeable difference in the given property (it's quite vague though, it's basically custom weighting factors)

I don't think that there is an obvious best, but I don't think it's needed and all gives sensible results.

A more sophisticated distance wouldn't be Euclidean. If you look at x-resolutions and y-resolutions independently you won't catch exotic aspect ratios which should be weighted more compared to a standard aspect ratio phone.

Re: Show HN: Similar Phone Finder

#25

Post by karmakaze » Wed, May 06, 2015, 4:01 PM UTC

leni536 wrote: post #19

Your euclidean distance formula is kind of wrong (at least on the site). The units of each term are incompatible so cannot be added together directly, they all should be normalized with a weight factor. A sensible weight factor would be the inverse of the standard deviation of the specific term. Alternatively you could use the inverse of the covariance matrix as the metric tensor of the properties since there could b…