Wikipedia:Reference desk/Archives/Computing/2016 November 26

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November 26

Grouping Points of A Partial Grid Into Squares

For a problem I am working on I need to the following: given an m by n array of 1's and 0's, partition the 1's into squares. In other words, I need to group the entries that are 1 into squares. My current method is to start at the upper left corner, find the first 1, then find the biggest square containing it, then find the next 1 not in it, do the same - moving across to the right, then down. This works fairly well for my purposes, but on certain arrays I'm getting a large number of squares that are 1x1, I would prefer a method that can find a more optimal partition (my arrays are not very "jagged", the boundaries between 1's and 0's are almost always vertical or horizontal segments, so I feel that a better solution should be possible). Thank you for any help.24.3.9.16 (talk) 07:01, 26 November 2016 (UTC)

Changes due to Crystal Oscillator

Is it possible to change a simple D.C. circuit (say 12 volts), to an A.C. circuit (frequency whatever) using this thing shown in the picture along ?

210.56.127.82 (talk) 18:03, 26 November 2016 (UTC)

No. If you have a DC circuit that you want to run off an AC supply, you'll need a rectifier - a single diode might be enough, or more sophisticated designs are available. If you want to generate AC from a DC supply, you'll need to build an oscillator - the crystal can be part of this, but it'll need several more components, including an amplifier of some sort. Tevildo (talk) 19:08, 26 November 2016 (UTC)

Yes, it's possible to derive an AC signal from a DC supply using the crystal device shown. Such devices may produce AC waveforms in the spectrum from 32.768 KHz (used in clocks and watches) or even lower, to hundreds of Megahertz. You haven't stated what frequency you want to obtain, so I'm loosely using AC to refer to any repetitive signal in that range. By dividing or multiplying the resultant signal, you can obtain the frequency you want. For example, you could divide a 3.93216 MHz crystal controlled device by 65,536 (2¹⁶) in digital circuitry to obtain 60Hz, the US mains frequency. This is a trivial task for digital division chips and is frequently employed in consumer electronic devices and industrial systems. Akld guy (talk) 00:00, 27 November 2016 (UTC)

Just to clarify, I interpreted "along" in the OP's question as a typo for "alone", so they'll need some additional components, not just the crystal, to make an oscillator. Applying DC to the crystal will not produce a waveform. Tevildo (talk) 10:36, 27 November 2016 (UTC)

Windows Equivalent of Android's Flud

Flud, available as an app for Android systems, is today most fast, easy to use and reliable Torrent agent. Is there any such application in Windows (using 7) that is worthy of such commendation ? 210.56.127.82 (talk) 18:30, 26 November 2016 (UTC)

https://alternativeto.net/software/flud/

I would skip the first one listed (µTorrent). It used to be good but became evil. qBittorrent is excellent.--Guy Macon (talk) 19:27, 26 November 2016 (UTC)

We have Comparison of BitTorrent clients. --47.138.163.230 (talk) 02:19, 27 November 2016 (UTC)