this post was submitted on 16 Jul 2023
37 points (63.5% liked)

Showerthoughts

29795 readers
605 users here now

A "Showerthought" is a simple term used to describe the thoughts that pop into your head while you're doing everyday things like taking a shower, driving, or just daydreaming. A showerthought should offer a unique perspective on an ordinary part of life.

Rules

  1. All posts must be showerthoughts
  2. The entire showerthought must be in the title
  3. Avoid politics
    • 3.1) NEW RULE as of 5 Nov 2024, trying it out
    • 3.2) Political posts often end up being circle jerks (not offering unique perspective) or enflaming (too much work for mods).
    • 3.3) Try c/politicaldiscussion, volunteer as a mod here, or start your own community.
  4. Posts must be original/unique
  5. Adhere to Lemmy's Code of Conduct

founded 1 year ago
MODERATORS
quinten
vatlark
forkball
Thekingoflorda
37
Why the fuck do cars still have analog speedometers? Surely digital ones would be more accurate and much easier to read without looking away from the road for too long. (self.showerthoughts)
submitted 1 year ago* (last edited 8 months ago) by JusticeForPorygon to c/showerthoughts
78 comments fedilink hide all child comments
 

Guys it's been 8 months. It was a bad take.

you are viewing a single comment's thread
view the rest of the comments
[–] [email protected] 1 points 1 year ago

I should have been more clear: The negative effects of quantisation. Obviously sampling into discrete values is shown but not the negative consequences that can have.
A DAC interpreting the blue trace will output something extremely close to the red one. There might be a slight bit of error in it due to the quantisation before but the graph does not show that and it probably couldn't since it'd be so tiny. A good way to show quantisation noise would be a histogram with a signal in the middle and some quantisation noise around it.

The DAC would not output the jaggy line. It couldn't, that's not a valid analog signal. Painting the steps between the points can be done if your audience knows what that means but can be extremely misleading if it doesn't. Those lines between the points with 90 degree angles don't exist in the real world, they're just interpolated between the points in the visualisation.
A much better way to represent digital samples in such a chart is the way it's done in the wikipedia article on the topic: https://en.wikipedia.org/wiki/Sampling_(signal_processing). They're just discrete points. If you did the same interpolation between the points as a DAC would do (which is not nearest-neighbour interpolation), you'd get the analog trace shown.