5 ms·

Huh? n-squared is an exponent

by tomc1985 6y ago

connor4312 6y ago
Exponential refers to c^N. N^c is quadratic. Small visualization: https://www.onlinemathlearning.com/image-files/exponential-quadratic-linear.png https://www.onlinemathlearning.com/image-files/exponential-q...
- mrits 6y ago
  It doesn't help that most people in journalism use the phrase exponential growth to describe quadratic growth.
- Akangka 6y ago
  We call that polynomial, not quadratic.
  - TomMarius 6y ago
    Both is right, quadratic being subset of polynomial.
brokensegue 6y ago
we call that "quadratic". exponential is when the exponent is variable. (unless I'm being whooshed)
- mabbo 6y ago
  No, you're 100% correct. O(n^[number]) = polynomial, with O(n^2) being quadratic. O([a number]^n) = exponential. I guess the authors aren't big on CS fundamentals?
- tomc1985 6y ago
  Indeed. It's been a while since I've had to so much as think about big O notation and I forgot that quirk. To most folks "exponential" means n^2 or greater
  - derefr 6y ago
    “Superlinear” is the word you’re looking for.
    - Monory 6y ago
      Superlinear can mean O(n log n) or anything like that, which is smaller than O(n^2).
  - recursive 6y ago
    Most folks are using the word wrong then.
whycombagator 6y ago
Sure, but for something to be considered exponential running time it must be <some-constant>^n. So 2^n would be exponential. However, n^2 is instead quadratic. Quadratic time complexity is better than exponential. Here is a useful comparison of the rate of growth for various time complexities[0] [0] https://stackoverflow.com/a/34517541/3574076 https://stackoverflow.com/a/34517541/3574076
- dgb23 6y ago
  Quadratic in this specific case, or more generally: polynomial.
toby 6y ago
n^0 is also an exponent. Do you consider constant time to be exponential growth?
- tomc1985 6y ago
  When family talks to me about covid spreading exponentially I am pretty sure they mean n times n, or n^2 Yes we all know the technical definitions with respect to software and algorithmic complexity. But the lack of sympathy/empathy on display with how a common definition of a word can be misconstrued by someone without an academic background in tech is kind of surprising (ok well maybe not so surprising but c'mon folks, we are all human)
  - brokensegue 6y ago
    disease spread when modeled is actually exponential. https://en.wikipedia.org/wiki/Basic_reproduction_number#Estimation_methods https://en.wikipedia.org/wiki/Basic_reproduction_number#Esti...

Huh? n-squared is an exponent

Exponential refers to c^N. N^c is quadratic. Small visualization: https://www.onlinemathlearning.com/image-files/exponential-quadratic-linear.png https://www.onlinemathlearning.com/image-files/exponential-q...

mrits 6y ago
It doesn't help that most people in journalism use the phrase exponential growth to describe quadratic growth.
Akangka 6y ago
We call that polynomial, not quadratic.
- TomMarius 6y ago
  Both is right, quadratic being subset of polynomial.

brokensegue 6y ago

we call that "quadratic". exponential is when the exponent is variable. (unless I'm being whooshed)

mabbo 6y ago
No, you're 100% correct. O(n^[number]) = polynomial, with O(n^2) being quadratic. O([a number]^n) = exponential. I guess the authors aren't big on CS fundamentals?
tomc1985 6y ago
Indeed. It's been a while since I've had to so much as think about big O notation and I forgot that quirk. To most folks "exponential" means n^2 or greater
- derefr 6y ago
  “Superlinear” is the word you’re looking for.
  - Monory 6y ago
    Superlinear can mean O(n log n) or anything like that, which is smaller than O(n^2).
- recursive 6y ago
  Most folks are using the word wrong then.

whycombagator 6y ago

Sure, but for something to be considered exponential running time it must be <some-constant>^n. So 2^n would be exponential. However, n^2 is instead quadratic. Quadratic time complexity is better than exponential. Here is a useful comparison of the rate of growth for various time complexities[0] [0] https://stackoverflow.com/a/34517541/3574076 https://stackoverflow.com/a/34517541/3574076

dgb23 6y ago
Quadratic in this specific case, or more generally: polynomial.

toby 6y ago

n^0 is also an exponent. Do you consider constant time to be exponential growth?

tomc1985 6y ago
When family talks to me about covid spreading exponentially I am pretty sure they mean n times n, or n^2 Yes we all know the technical definitions with respect to software and algorithmic complexity. But the lack of sympathy/empathy on display with how a common definition of a word can be misconstrued by someone without an academic background in tech is kind of surprising (ok well maybe not so surprising but c'mon folks, we are all human)
- brokensegue 6y ago
  disease spread when modeled is actually exponential. https://en.wikipedia.org/wiki/Basic_reproduction_number#Estimation_methods https://en.wikipedia.org/wiki/Basic_reproduction_number#Esti...