Martin Maechler
2019-Oct-18 12:51 UTC
[R] "chi-square" | "chi-squared" | "chi squared" | "chi square" ?
As it's Friday ..
and I also really want to clean up help files and similar R documents,
both in R's own sources and in my new 'DPQ' CRAN package :
As a trained mathematician, I'm uneasy if a thing has
several easily confusable names, .. but as somewhat
humanistically educated person, I know that natural languages,
English in this case, are much more flexible than computer
languages or math...
Anyway, back to the question(s) .. which I had asked myself a
couple of months ago, and already remained slightly undecided:
The 0-th (meta-)question of course is
0. Is it worth using only one written form for the
?? - distribution, e.g. "everywhere" in R?
The answer is not obvious, as already the first few words of the
(English) Wikipedia clearly convey:
The URL is https://en.wikipedia.org/wiki/Chi-squared_distribution
and the main title therefore also
"Chi-squared distribution"
Then it reads
> This article is about the mathematics of the chi-squared
> distribution. For its uses in statistics, see chi-squared
> test. For the music [...]
> In probability theory and statistics, the chi-square
> distribution (also chi-squared or ?2-distribution) with k
> degrees of freedom is the distribution of a sum of the squares
> of k independent standard normal random variables.
> The chi-square distribution is a special case of the gamma
> distribution and is one of the most widely used probability
> distributions in inferential statistics, notably in hypothesis
> testing [........]
> [........]
So, in title and 1st paragraph its "chi-squared", but then
everywhere(?) the text used "chi-square".
Undoubtedly, Wilson & Hilferty (1931) has been an important
paper and they use "Chi-square" in the title;
also Johnson, Kotz & Balakrishnan (1995)
see R's help page ?pchisq use "Chi-square" in the title of
chapter 18 and then, diplomatically for chapter 29,
"Noncentral ??-Distributions" as title.
So it seems, that historically and using prestigious sources,
"chi-square" to dominate (notably if we do not count "??" as
an
alternative).
Things look a bit different when I study R's sources; on one
hand, I find all 4 forms (s.Subject); then in the "R source
history", I see
$ svn log -c11342
------------------------------------------------------------------------
r11342 | <....> | 2000-11-14 ...
Use `chi-squared'.
------------------------------------------------------------------------
which changed 16 (if I counted correctly) cases of 'chi-square' to
'chi-squared'.
I have not found any R-core internal (or public) reasoning about
that change, but had kept it in mind and often worked along that
"goal".
As a consequence, "statistically" speaking, much of R's own use
has been
standardized to use "chi-squared"; but as I mentioned, I still
find all 4 variants even in "R base" package help files
(which of course I now could quite quickly change (using Emacs M-x grep, plus a
script);
but
... "as it is Friday" ... I'm interested to hear what others
think, notably if you are native English (or "American" ;-)
speaking and/or have some extra good knowledge on such
matters...
Martin Maechler
ETH Zurich
Dénes Tóth
2019-Oct-18 13:19 UTC
[R] "chi-square" | "chi-squared" | "chi squared" | "chi square" ?
Dear Martin, Others struggle with this inconsistency as well; I found this discussion useful: https://math.stackexchange.com/questions/1098138/chi-square-or-chi-squared Denes On 10/18/19 2:51 PM, Martin Maechler wrote:> As it's Friday .. > > and I also really want to clean up help files and similar R documents, > both in R's own sources and in my new 'DPQ' CRAN package : > > As a trained mathematician, I'm uneasy if a thing has > several easily confusable names, .. but as somewhat > humanistically educated person, I know that natural languages, > English in this case, are much more flexible than computer > languages or math... > > Anyway, back to the question(s) .. which I had asked myself a > couple of months ago, and already remained slightly undecided: > > The 0-th (meta-)question of course is > > 0. Is it worth using only one written form for the > ?? - distribution, e.g. "everywhere" in R? > > The answer is not obvious, as already the first few words of the > (English) Wikipedia clearly convey: > > The URL is https://en.wikipedia.org/wiki/Chi-squared_distribution > and the main title therefore also > "Chi-squared distribution" > > Then it reads > >> This article is about the mathematics of the chi-squared >> distribution. For its uses in statistics, see chi-squared >> test. For the music [...] > >> In probability theory and statistics, the chi-square >> distribution (also chi-squared or ?2-distribution) with k >> degrees of freedom is the distribution of a sum of the squares >> of k independent standard normal random variables. > >> The chi-square distribution is a special case of the gamma >> distribution and is one of the most widely used probability >> distributions in inferential statistics, notably in hypothesis >> testing [........] >> [........] > > So, in title and 1st paragraph its "chi-squared", but then > everywhere(?) the text used "chi-square". > > Undoubtedly, Wilson & Hilferty (1931) has been an important > paper and they use "Chi-square" in the title; > also Johnson, Kotz & Balakrishnan (1995) > see R's help page ?pchisq use "Chi-square" in the title of > chapter 18 and then, diplomatically for chapter 29, > "Noncentral ??-Distributions" as title. > > So it seems, that historically and using prestigious sources, > "chi-square" to dominate (notably if we do not count "??" as an > alternative). > > Things look a bit different when I study R's sources; on one > hand, I find all 4 forms (s.Subject); then in the "R source > history", I see > > $ svn log -c11342 > ------------------------------------------------------------------------ > r11342 | <....> | 2000-11-14 ... > > Use `chi-squared'. > ------------------------------------------------------------------------ > > which changed 16 (if I counted correctly) cases of 'chi-square' to 'chi-squared'. > > I have not found any R-core internal (or public) reasoning about > that change, but had kept it in mind and often worked along that "goal". > > As a consequence, "statistically" speaking, much of R's own use has been > standardized to use "chi-squared"; but as I mentioned, I still > find all 4 variants even in "R base" package help files > (which of course I now could quite quickly change (using Emacs M-x grep, plus a script); > but > > ... "as it is Friday" ... I'm interested to hear what others > think, notably if you are native English (or "American" ;-) > speaking and/or have some extra good knowledge on such > matters... > > Martin Maechler > ETH Zurich > > ______________________________________________ > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. >
Rolf Turner
2019-Oct-18 20:19 UTC
[R] "chi-square" | "chi-squared" | "chi squared" | "chi square" ?
I have the vague impression that "chi-squared" is more common in British usage and "chi-square" more common in American usage. I'm pretty sure that either is acceptable, although "chi-squared" sounds much better to my ear. Of course within a given document (or collection of related documents) consistency is mandatory. cheers, Rolf On 19/10/19 1:51 AM, Martin Maechler wrote:> As it's Friday .. > > and I also really want to clean up help files and similar R documents, > both in R's own sources and in my new 'DPQ' CRAN package : > > As a trained mathematician, I'm uneasy if a thing has > several easily confusable names, .. but as somewhat > humanistically educated person, I know that natural languages, > English in this case, are much more flexible than computer > languages or math... > > Anyway, back to the question(s) .. which I had asked myself a > couple of months ago, and already remained slightly undecided: > > The 0-th (meta-)question of course is > > 0. Is it worth using only one written form for the > ?? - distribution, e.g. "everywhere" in R? > > The answer is not obvious, as already the first few words of the > (English) Wikipedia clearly convey: > > The URL is https://en.wikipedia.org/wiki/Chi-squared_distribution > and the main title therefore also > "Chi-squared distribution" > > Then it reads > >> This article is about the mathematics of the chi-squared >> distribution. For its uses in statistics, see chi-squared >> test. For the music [...] > >> In probability theory and statistics, the chi-square >> distribution (also chi-squared or ?2-distribution) with k >> degrees of freedom is the distribution of a sum of the squares >> of k independent standard normal random variables. > >> The chi-square distribution is a special case of the gamma >> distribution and is one of the most widely used probability >> distributions in inferential statistics, notably in hypothesis >> testing [........] >> [........] > > So, in title and 1st paragraph its "chi-squared", but then > everywhere(?) the text used "chi-square". > > Undoubtedly, Wilson & Hilferty (1931) has been an important > paper and they use "Chi-square" in the title; > also Johnson, Kotz & Balakrishnan (1995) > see R's help page ?pchisq use "Chi-square" in the title of > chapter 18 and then, diplomatically for chapter 29, > "Noncentral ??-Distributions" as title. > > So it seems, that historically and using prestigious sources, > "chi-square" to dominate (notably if we do not count "??" as an > alternative). > > Things look a bit different when I study R's sources; on one > hand, I find all 4 forms (s.Subject); then in the "R source > history", I see > > $ svn log -c11342 > ------------------------------------------------------------------------ > r11342 | <....> | 2000-11-14 ... > > Use `chi-squared'. > ------------------------------------------------------------------------ > > which changed 16 (if I counted correctly) cases of 'chi-square' to 'chi-squared'. > > I have not found any R-core internal (or public) reasoning about > that change, but had kept it in mind and often worked along that "goal". > > As a consequence, "statistically" speaking, much of R's own use has been > standardized to use "chi-squared"; but as I mentioned, I still > find all 4 variants even in "R base" package help files > (which of course I now could quite quickly change (using Emacs M-x grep, plus a script); > but > > ... "as it is Friday" ... I'm interested to hear what others > think, notably if you are native English (or "American" ;-) > speaking and/or have some extra good knowledge on such > matters...
Jim Lemon
2019-Oct-18 20:20 UTC
[R] "chi-square" | "chi-squared" | "chi squared" | "chi square" ?
I have thought about this one myself, and just reading the posts and links has afforded me a more informed viewpoint. My guess is that it boils down to a contest between mathematics and prosody. To speakers of English, "square" in the mathematical sense implies the active form such as "I square this number". When our focus is on the number itself, it is usually expressed as "This number has been squared". My suggestion is that while "chi-square" may be more correct in the derivation of the statistic, "chi-squared" is more consistent with colloquial usage in using the passive form. It may also avoid confusion with the use of "square" as a noun, in which the preceding word is often an adjective (e.g. "a red square"). Jim On Sat, Oct 19, 2019 at 12:19 AM D?nes T?th <toth.denes at kogentum.hu> wrote:> > Dear Martin, > > Others struggle with this inconsistency as well; I found this discussion > useful: > https://math.stackexchange.com/questions/1098138/chi-square-or-chi-squared > > Denes > > > On 10/18/19 2:51 PM, Martin Maechler wrote: > > As it's Friday .. > > > > and I also really want to clean up help files and similar R documents, > > both in R's own sources and in my new 'DPQ' CRAN package : > > > > As a trained mathematician, I'm uneasy if a thing has > > several easily confusable names, .. but as somewhat > > humanistically educated person, I know that natural languages, > > English in this case, are much more flexible than computer > > languages or math... > > > > Anyway, back to the question(s) .. which I had asked myself a > > couple of months ago, and already remained slightly undecided: > > > > The 0-th (meta-)question of course is > > > > 0. Is it worth using only one written form for the > > ?? - distribution, e.g. "everywhere" in R? > > > > The answer is not obvious, as already the first few words of the > > (English) Wikipedia clearly convey: > > > > The URL is https://en.wikipedia.org/wiki/Chi-squared_distribution > > and the main title therefore also > > "Chi-squared distribution" > > > > Then it reads > > > >> This article is about the mathematics of the chi-squared > >> distribution. For its uses in statistics, see chi-squared > >> test. For the music [...] > > > >> In probability theory and statistics, the chi-square > >> distribution (also chi-squared or ?2-distribution) with k > >> degrees of freedom is the distribution of a sum of the squares > >> of k independent standard normal random variables. > > > >> The chi-square distribution is a special case of the gamma > >> distribution and is one of the most widely used probability > >> distributions in inferential statistics, notably in hypothesis > >> testing [........] > >> [........] > > > > So, in title and 1st paragraph its "chi-squared", but then > > everywhere(?) the text used "chi-square". > > > > Undoubtedly, Wilson & Hilferty (1931) has been an important > > paper and they use "Chi-square" in the title; > > also Johnson, Kotz & Balakrishnan (1995) > > see R's help page ?pchisq use "Chi-square" in the title of > > chapter 18 and then, diplomatically for chapter 29, > > "Noncentral ??-Distributions" as title. > > > > So it seems, that historically and using prestigious sources, > > "chi-square" to dominate (notably if we do not count "??" as an > > alternative). > > > > Things look a bit different when I study R's sources; on one > > hand, I find all 4 forms (s.Subject); then in the "R source > > history", I see > > > > $ svn log -c11342 > > ------------------------------------------------------------------------ > > r11342 | <....> | 2000-11-14 ... > > > > Use `chi-squared'. > > ------------------------------------------------------------------------ > > > > which changed 16 (if I counted correctly) cases of 'chi-square' to 'chi-squared'. > > > > I have not found any R-core internal (or public) reasoning about > > that change, but had kept it in mind and often worked along that "goal". > > > > As a consequence, "statistically" speaking, much of R's own use has been > > standardized to use "chi-squared"; but as I mentioned, I still > > find all 4 variants even in "R base" package help files > > (which of course I now could quite quickly change (using Emacs M-x grep, plus a script); > > but > > > > ... "as it is Friday" ... I'm interested to hear what others > > think, notably if you are native English (or "American" ;-) > > speaking and/or have some extra good knowledge on such > > matters... > > > > Martin Maechler > > ETH Zurich > > > > ______________________________________________ > > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > > and provide commented, minimal, self-contained, reproducible code. > > > > ______________________________________________ > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.
Richard M. Heiberger
2019-Oct-18 21:26 UTC
[R] "chi-square" | "chi-squared" | "chi squared" | "chi square" ?
What a delightful question. Bill Cochran discussed this in class one day about 50 years ago. He said the British usage (which I think he said was chi-squared, as is consistent with the other memories in this thread) is what he learned and previously used. But he had been in the US for so long that he was now using the American preference (chi-square). Rich On Fri, Oct 18, 2019 at 8:51 AM Martin Maechler <maechler at stat.math.ethz.ch> wrote:> > As it's Friday .. > > and I also really want to clean up help files and similar R documents, > both in R's own sources and in my new 'DPQ' CRAN package : > > As a trained mathematician, I'm uneasy if a thing has > several easily confusable names, .. but as somewhat > humanistically educated person, I know that natural languages, > English in this case, are much more flexible than computer > languages or math... > > Anyway, back to the question(s) .. which I had asked myself a > couple of months ago, and already remained slightly undecided: > > The 0-th (meta-)question of course is > > 0. Is it worth using only one written form for the > ?? - distribution, e.g. "everywhere" in R? > > The answer is not obvious, as already the first few words of the > (English) Wikipedia clearly convey: > > The URL is https://en.wikipedia.org/wiki/Chi-squared_distribution > and the main title therefore also > "Chi-squared distribution" > > Then it reads > > > This article is about the mathematics of the chi-squared > > distribution. For its uses in statistics, see chi-squared > > test. For the music [...] > > > In probability theory and statistics, the chi-square > > distribution (also chi-squared or ?2-distribution) with k > > degrees of freedom is the distribution of a sum of the squares > > of k independent standard normal random variables. > > > The chi-square distribution is a special case of the gamma > > distribution and is one of the most widely used probability > > distributions in inferential statistics, notably in hypothesis > > testing [........] > > [........] > > So, in title and 1st paragraph its "chi-squared", but then > everywhere(?) the text used "chi-square". > > Undoubtedly, Wilson & Hilferty (1931) has been an important > paper and they use "Chi-square" in the title; > also Johnson, Kotz & Balakrishnan (1995) > see R's help page ?pchisq use "Chi-square" in the title of > chapter 18 and then, diplomatically for chapter 29, > "Noncentral ??-Distributions" as title. > > So it seems, that historically and using prestigious sources, > "chi-square" to dominate (notably if we do not count "??" as an > alternative). > > Things look a bit different when I study R's sources; on one > hand, I find all 4 forms (s.Subject); then in the "R source > history", I see > > $ svn log -c11342 > ------------------------------------------------------------------------ > r11342 | <....> | 2000-11-14 ... > > Use `chi-squared'. > ------------------------------------------------------------------------ > > which changed 16 (if I counted correctly) cases of 'chi-square' to 'chi-squared'. > > I have not found any R-core internal (or public) reasoning about > that change, but had kept it in mind and often worked along that "goal". > > As a consequence, "statistically" speaking, much of R's own use has been > standardized to use "chi-squared"; but as I mentioned, I still > find all 4 variants even in "R base" package help files > (which of course I now could quite quickly change (using Emacs M-x grep, plus a script); > but > > ... "as it is Friday" ... I'm interested to hear what others > think, notably if you are native English (or "American" ;-) > speaking and/or have some extra good knowledge on such > matters... > > Martin Maechler > ETH Zurich > > ______________________________________________ > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.
Dalthorp, Daniel
2019-Oct-18 22:25 UTC
[R] [EXTERNAL] Re: "chi-square" | "chi-squared" | "chi squared" | "chi square" ?
oh my... I'd like to see the statistics on it before jumping to a conclusion that the American preference is "chi-square" and the British preference is "chi-squared". I don't see that at all. ------ In keeping with the pronunciation of x^2 and 3^2, maybe "chi-squared" makes the most sense,. The "chi-square"? Because the iterated dentals in "chi-squared distribution" and "chi-squared test" are a little cumbersome to pronounce, an even slightly lazy pronunciation would sound like "chi-square distribution" and "chi-square test". There's no need to write it that way though. -Dan On Fri, Oct 18, 2019 at 2:28 PM Richard M. Heiberger <rmh at temple.edu> wrote:> What a delightful question. Bill Cochran discussed this in class > one day about 50 years ago. He said the British usage (which I think > he said was chi-squared, > as is consistent with the other memories in this thread) > is what he learned and previously used. But he had been in the US for > so long that he was now using > the American preference (chi-square). > > Rich > > On Fri, Oct 18, 2019 at 8:51 AM Martin Maechler > <maechler at stat.math.ethz.ch> wrote: > > > > As it's Friday .. > > > > and I also really want to clean up help files and similar R documents, > > both in R's own sources and in my new 'DPQ' CRAN package : > > > > As a trained mathematician, I'm uneasy if a thing has > > several easily confusable names, .. but as somewhat > > humanistically educated person, I know that natural languages, > > English in this case, are much more flexible than computer > > languages or math... > > > > Anyway, back to the question(s) .. which I had asked myself a > > couple of months ago, and already remained slightly undecided: > > > > The 0-th (meta-)question of course is > > > > 0. Is it worth using only one written form for the > > ?? - distribution, e.g. "everywhere" in R? > > > > The answer is not obvious, as already the first few words of the > > (English) Wikipedia clearly convey: > > > > The URL is https://en.wikipedia.org/wiki/Chi-squared_distribution > > and the main title therefore also > > "Chi-squared distribution" > > > > Then it reads > > > > > This article is about the mathematics of the chi-squared > > > distribution. For its uses in statistics, see chi-squared > > > test. For the music [...] > > > > > In probability theory and statistics, the chi-square > > > distribution (also chi-squared or ?2-distribution) with k > > > degrees of freedom is the distribution of a sum of the squares > > > of k independent standard normal random variables. > > > > > The chi-square distribution is a special case of the gamma > > > distribution and is one of the most widely used probability > > > distributions in inferential statistics, notably in hypothesis > > > testing [........] > > > [........] > > > > So, in title and 1st paragraph its "chi-squared", but then > > everywhere(?) the text used "chi-square". > > > > Undoubtedly, Wilson & Hilferty (1931) has been an important > > paper and they use "Chi-square" in the title; > > also Johnson, Kotz & Balakrishnan (1995) > > see R's help page ?pchisq use "Chi-square" in the title of > > chapter 18 and then, diplomatically for chapter 29, > > "Noncentral ??-Distributions" as title. > > > > So it seems, that historically and using prestigious sources, > > "chi-square" to dominate (notably if we do not count "??" as an > > alternative). > > > > Things look a bit different when I study R's sources; on one > > hand, I find all 4 forms (s.Subject); then in the "R source > > history", I see > > > > $ svn log -c11342 > > > ------------------------------------------------------------------------ > > r11342 | <....> | 2000-11-14 ... > > > > Use `chi-squared'. > > > ------------------------------------------------------------------------ > > > > which changed 16 (if I counted correctly) cases of 'chi-square' to > 'chi-squared'. > > > > I have not found any R-core internal (or public) reasoning about > > that change, but had kept it in mind and often worked along that "goal". > > > > As a consequence, "statistically" speaking, much of R's own use has been > > standardized to use "chi-squared"; but as I mentioned, I still > > find all 4 variants even in "R base" package help files > > (which of course I now could quite quickly change (using Emacs M-x > grep, plus a script); > > but > > > > ... "as it is Friday" ... I'm interested to hear what others > > think, notably if you are native English (or "American" ;-) > > speaking and/or have some extra good knowledge on such > > matters... > > > > Martin Maechler > > ETH Zurich > > > > ______________________________________________ > > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > > and provide commented, minimal, self-contained, reproducible code. > > ______________________________________________ > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. >-- Dan Dalthorp, PhD USGS Forest and Rangeland Ecosystem Science Center Forest Sciences Lab, Rm 311 3200 SW Jefferson Way Corvallis, OR 97331 ph: 541-750-0953 ddalthorp at usgs.gov [[alternative HTML version deleted]]