Talk:2585: Rounding

Explain xkcd: It's 'cause you're dumb.
Revision as of 18:06, 24 February 2022 by 172.70.131.122 (talk) (observation on rounding conventions)
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Wot no furlongs per fortnight? 172.70.91.126 23:14, 23 February 2022 (UTC)

I, too, was initially surprised that Randall hadn't used the standard joke measure. But, then I realized that F/F is so outrageously large that rounding wouldn't offer much advantage. MAP (talk) 05:10, 24 February 2022 (UTC)

If we're using the table, can I suggest it be fully filled in, but mark "original (rounded)" value cells one key colour and the chosen conversion in another, so that scanning along (not necessarily adjacent/rightwards) then down (always next row) then along... you see the 'bounce around'. And we also get to appreciate what other fractional values could have been chosen, prior to rounding... Alternately, some flow-charty layout (perhaps contained within a nominally borderless version of the table?) with arrows leading across the width and filling in-between each down-step. Ideas only. I have others, but those seem the best bet to consider. 172.70.85.113 01:32, 24 February 2022 (UTC)

Disagree with the current (as of 23:27 US Eastern, 23 February) explanation. According to this site (https://ilovebicycling.com/average-bike-speed/), average downhill bike speed is over 45 mph. Since Cueball doesn't specify "on flat terrain", he should have no problem going 45 without exploiting imprecise conversions. Nitpicking (talk) 04:30, 24 February 2022 (UTC)

Huh? This does not say average downhill speed is > 45, it says "fastest". Also why would Cueball need to do this bizarre rounding if he can actually go 45mph? This is an exaggeration because he can only go a typical speed of 17mph.172.69.33.145 04:52, 24 February 2022 (UTC)
Fastest for average cyclist. -- Hkmaly (talk) 05:05, 24 February 2022 (UTC)
As a cyclist of several decades experience, who has indeed attained such speeds on rare (reckless) occasions, I think that "fastest downhill speed for an average rider" is overstated. Maybe it is what average people are capable of on a well-surfaced, steep, straight, non-undulating road with sufficient vision (forward and of anything potentially moving into the road from the side) or at least confidence that you're not dealing with traffic/pedestrians/other unaware cyclists. Oh, and sufficient stopping distance for whatever brakes you have.
Maybe everybody can do it once, but a good bike-ride should be one you can walk away from at the end.
(Also, that cycling-centric site might have a different idea of 'average' cyclist. The average person on a bike here can't even put their feet on the pedals correctly. If we're talking club-/competitive-cyclists (but still sub-pro) then I'd much more readily agree, but there are far more people these days who can't even ride on the roadway, it seems.)
That bike, as drawn, looks like it'll be Okish (if kept well maintained) but not exactly set up as functional downhill racer, nor probably is the rider. I really think the machine probably could be ridden at 20+mph on the flat for as long as the rider can stand to, but the characterisation makes me not confident they're able to maintain that kind of average speed for a long ride, and I think they'd overbake a downhill speed-run too, or (sensibly) be more cautious. 172.70.85.143 05:14, 24 February 2022 (UTC)
Yep - the speeds on that site are for road bikes. Cueball looks to be riding a hybrid (flat bars), which would tend to put him in a more upright position, creating a higher frontal area and air resistance, and so slowing his progress. That would have even more of an effect at higher speeds. 162.158.159.43 11:14, 24 February 2022 (UTC)

Arguably, once you're up to numbers around 45, you're as likely, if not more so, to be rounding to the nearest 5 than the nearest unit (depending on context). So Cueball's initial statement could be taken as suggesting that he can ride at around 42.5 - 47.5mph (rather than 44.5 - 45.5mph). And if he could actually ride at over 45mph then he presumably wouldn't need to add the 'if you round' qualifier, so it could further be taken as just suggesting that he can exceed 42.5mph. 162.158.159.43 11:22, 24 February 2022 (UTC)

Note I find it kind of disappointing that the insane "KPH" unit is used in the comic. Nobody uses that in places where speed is actually measured in km/h.

Ironically, by the same standards it only takes one conversion to say that he can't move at all on a bike. he goes 0 parsecs, lightyears or AU (for example) per year, decade or century (for example).


Can we remove the rounding errors in the "exact" values in the tables? For instance, the final value should be "45.0000" not "45.0001". In fact, all three values ending with 0001 are rounding errors. (These were probably a result of converting to metric and back, using low precision conversion factors.) Divad27182 (talk) 15:49, 24 February 2022 (UTC)

Whoever decided to display that information in that table deserves an award. Gg. 172.70.126.65 16:38, 24 February 2022 (UTC)

It's nice how the rounding of exact half-integers only ever has to deal with odd-numbers-and-a-half, so Cueball can't be charged with violating the "round to even" rule, nor with violating the "round away from zero" rule. 172.70.131.122 18:06, 24 February 2022 (UTC)