Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Mathematical Jargon Failures

blog.plover.com

Post reply on HN
Print view View original

61–70 of 77 posts

Re: Mathematical Jargon Failures

#61

Post by UnFleshedOne »

whooshee wrote: post #7
pfortuny wrote: post #4

The Type I and Type II errors is especially hurtful to me: I am totally unable to remember which is which and each time I read an article containing them I think: well, I am probably going to get it wrong again but I cannot bother to check the definition one more time... who cares?

Same here, and some definitions named by people's names. I totally understand the need to attribute and respect people's work, but a more descriptive name is almost always easier to remember and talk about.

Descriptive names, even when possible, translate very poorly to other languages.

Re: Mathematical Jargon Failures

#62

Post by yummypaint »

rbonvall wrote: post #45

One I hate is sin^{2}(x) meaning "sine squared" and sin^{-1}(x) meaning "the inverse of the sine function".

Idk why people dont just keep the exponents after the function as is already the general convention. Sin^{-1}(x)^2 Sin(x)^2 This one annoys me because it's so preventable.

Re: Mathematical Jargon Failures

#63

Post by twic »

roelschroeven wrote: post #15
majewsky wrote: post #8

Earlier quoted context omitted.

IT is full of jargon as well. Where else would it make sense to cherry-pick commits into a branch and then ask others to pull that branch into their repository? :) My German team has a running gag where, when a sentence turns out especially jargon-riddled, we translate all the jargon words into German, as literally as possible. The result is always hilarious.

Sometimes IT and biology share some jargon, or at least they share the words but not exactly the meaning. Both in IT and biology a collection of trees is called a forest. In IT, if you take a tree and remove the root, the result is a forest. Biologists don't agree.

> In IT, if you take a tree and remove the root, the result is a forest. Biologists don't agree.

Unless it's Pando:

https://en.wikipedia.org/wiki/Pando_(tree)

Re: Mathematical Jargon Failures

#64

Post by twic »

airstrike wrote: post #20
man-and-laptop wrote: post #19

The function f(x)=1/x is continuous, but its graph is not connected. It's an interesting one to explain to people.

Few things bother me more in life than the prevalence of Pi over Tau

I wonder, could a font have a ligature for the sequence "2π" that rendered it as τ?

Re: Mathematical Jargon Failures

#65

Post by abecedarius »

Kalium wrote: post #60
abecedarius wrote: post #52

Earlier quoted context omitted.

I'm not sure I get what distinction you're making. Are you saying that the standard terms don't commit to what we mean by a test's positive/negative, and this generality is more valuable than concreteness? It would be bad to imply too generally that we're talking about a test that says yes or no, a thing is present or absent?

I'm saying that in my opinion, the standard terms are pretty clear and yes or no create exactly the kind of confusion you're hoping to avoid.

Huh. Positive and negative are sort of notorious in medical tests for creating a confusion: positive is often bad!

There are actually three dichotomies here: was the test mistaken, what was its boolean value, and which boolean value means which thing in the world. Saying yes/no still requires a decision about the latter; though it seems clearer to me about this (both the need for interpretation and on suggesting a default), but it is subjective. And of course, any of these are better than Type I/II.

I do kind of insist that right/wrong or correct/mistaken clearly means the first question, where true/false is more ambiguous. To really resolve things maybe a better idea is like wrong/present and right/absent.

Re: Mathematical Jargon Failures

#66

Post by weinzierl »

tempguy9999 wrote: post #28
tempodox wrote: post #22

I'm glad to see I'm not alone in my desperation over the fact that names in math don't always mean what they seem to mean. Intelligent programmers have noted more than once that naming things is one of the greatest challenges. In hindsight, it shouldn't be too surprising that math suffers from the same difficulty.

Oh yes. I've a book on dynamic programming (Applied Dynamic Programming, Bellman + Dreyfus, seriously over my head unfortunately) which uses missionaries, cannibals and a boat to cross a river (page 97). The authors talk about M cannibals and N missionaries. Note again: he used the letter M for cannibals, not the missionaries, which I note start with that letter. And he could have called the cannibals C but, no. I li…

i, j, k, l, m ,n suggest that this problem is concerned with an integral number of cannibals and missionaries. Usually these letters are assigned in the order of occurrence. If cannibals were introduced first and missionaries second it would be unnatural to assign missionaries an m. Further a c for cannibals would be counter-intuitive because c is often used for constants.

> Mathematicians really do make things hard sometimes.

Hard for non-mathematicians for sure, hard for themselves often enough too; but not this time.

Re: Mathematical Jargon Failures

#67

Post by Balgair »

joker3 wrote: post #57
pfortuny wrote: post #4

The Type I and Type II errors is especially hurtful to me: I am totally unable to remember which is which and each time I read an article containing them I think: well, I am probably going to get it wrong again but I cannot bother to check the definition one more time... who cares?

You know the story of the boy who cried wolf? The villagers committed several type I errors first, and then a type II error second. (Yes, the terminology is stupid and should be changed. But as long as we're stuck with it, this helps.)

Wonderful mnemonic, thank you!

Re: Mathematical Jargon Failures

#68

Post by Balgair »

In spherical coordinates, the Physicists use Phi for the azimuthal angle, and Theta for the equatorial angle. While the mathematicians use the opposite. That was always fun trying to switch between for the various classes.

Additionally, the physicists use 'i' for electrical current, while the electrical engineers use 'j'. Again, very fun trying to remember what is what during finals week.

Re: Mathematical Jargon Failures

#69

Post by aesthesia »

Even and odd functions don't form a partition of the space of all functions, but they do span it as a vector space. What's more, the vector space of functions is the direct sum of the even and odd functions: every function has a unique decomposition as a sum of an even and an odd function. So the problem there is that vector spaces don't behave the same way as sets.

Re: Mathematical Jargon Failures

#70

Post by no_identd »

Balgair wrote: post #68

In spherical coordinates, the Physicists use Phi for the azimuthal angle, and Theta for the equatorial angle. While the mathematicians use the opposite. That was always fun trying to switch between for the various classes. Additionally, the physicists use 'i' for electrical current, while the electrical engineers use 'j'. Again, very fun trying to remember what is what during finals week.

>Additionally, the physicists use 'i' for electrical current, while the electrical engineers use 'j'.

Sir William Rowan Hamilton would like to have a word with you. I think he mumbled something about some bridge or something?

Post reply on HN