Calculate the Mean mean of two numbers
$begingroup$
disclaimer: the Mean mean is made up by me
Define the arithmetic mean of $n$ numbers as
$$M_1(x_1,...,x_n)=frac{x_1+x_2+...+x_n}{n}$$
Define the geometric mean of $n$ numbers as
$$M_0(x_1,...,x_n)=root{n}of{x_1x_2...x_n}$$
Define the harmonic mean of $n$ numbers as
$$M_{-1}(x_1,...,x_n)=frac{n}{frac{1}{x_2} + frac{1}{x_2} + ... + frac{1}{x_n}}$$
Define the quadratic mean of $n$ numbers as
$$M_2(x_1,...,x_n)=rootof{frac{x_1^2+x_2^2+...+x_n^2}{n}}$$
The Mean mean ($M_M$) is defined as follows:
Define four sequences ($a_k, b_k, c_k, d_k$) as $$a_0=M_1(x_1,...,x_n),\b_0=M_0(x_1,...,x_n),\c_0=M_{-1}(x_1,...,x_n),\d_0=M_2(x_1,...,x_n),\
a_{k+1}=M_1(a_k,b_k,c_k,d_k),\b_{k+1}=M_0(a_k,b_k,c_k,d_k),\c_{k+1}=M_{-1}(a_k,b_k,c_k,d_k),\d_{k+1}=M_2(a_k,b_k,c_k,d_k)$$
All four sequences converge to the same number, $M_M(x_1,x_2,...,x_n)$.
Example
The Mean mean of 1 and 2 is calculated as follows: start with $$a_0 = (1+2)/2 = 1.5, b_0 = rootof{1 * 2} = rootof2 approx 1.4142,\ c_0 = frac2{frac1{1}+frac1{2}} = frac4{3} approx 1.3333, d_0 = rootof{frac{1^2+2^2}2} = rootof{frac5{2}} approx 1.5811.$$
Then
$$a_1 = frac{1.5+1.4142+1.3333+1.5811}4 approx 1.4571,\ b_1 = root^4of{1.5*1.4142*1.3333*1.5811} approx 1.4542,\ c_1 = frac4{frac1{1.5}+frac1{1.4142}+frac1{1.3333}+frac1{1.5811}} approx 1.4512,\ d_1 = rootof{frac{1.5^2+1.4142^2+1.3333^2+1.5811^2}4} approx 1.4601.$$
The further calculation of the sequences should be clear. It can be seen that they converge to the same number, approximately $1.45568889$.
Challenge
Given two positive real numbers, $a$ and $b$, calculate their Mean mean $M_M(a,b)$.
Test cases
1 1 => 1
1 2 => 1.45568889
100 200 => 145.568889
2.71 3.14 => 2.92103713
0.57 1.78 => 1.0848205
1.61 2.41 => 1.98965438
0.01 100 => 6.7483058
This is code-golf, so the shortest code wins!
code-golf math
$endgroup$
add a comment |
$begingroup$
disclaimer: the Mean mean is made up by me
Define the arithmetic mean of $n$ numbers as
$$M_1(x_1,...,x_n)=frac{x_1+x_2+...+x_n}{n}$$
Define the geometric mean of $n$ numbers as
$$M_0(x_1,...,x_n)=root{n}of{x_1x_2...x_n}$$
Define the harmonic mean of $n$ numbers as
$$M_{-1}(x_1,...,x_n)=frac{n}{frac{1}{x_2} + frac{1}{x_2} + ... + frac{1}{x_n}}$$
Define the quadratic mean of $n$ numbers as
$$M_2(x_1,...,x_n)=rootof{frac{x_1^2+x_2^2+...+x_n^2}{n}}$$
The Mean mean ($M_M$) is defined as follows:
Define four sequences ($a_k, b_k, c_k, d_k$) as $$a_0=M_1(x_1,...,x_n),\b_0=M_0(x_1,...,x_n),\c_0=M_{-1}(x_1,...,x_n),\d_0=M_2(x_1,...,x_n),\
a_{k+1}=M_1(a_k,b_k,c_k,d_k),\b_{k+1}=M_0(a_k,b_k,c_k,d_k),\c_{k+1}=M_{-1}(a_k,b_k,c_k,d_k),\d_{k+1}=M_2(a_k,b_k,c_k,d_k)$$
All four sequences converge to the same number, $M_M(x_1,x_2,...,x_n)$.
Example
The Mean mean of 1 and 2 is calculated as follows: start with $$a_0 = (1+2)/2 = 1.5, b_0 = rootof{1 * 2} = rootof2 approx 1.4142,\ c_0 = frac2{frac1{1}+frac1{2}} = frac4{3} approx 1.3333, d_0 = rootof{frac{1^2+2^2}2} = rootof{frac5{2}} approx 1.5811.$$
Then
$$a_1 = frac{1.5+1.4142+1.3333+1.5811}4 approx 1.4571,\ b_1 = root^4of{1.5*1.4142*1.3333*1.5811} approx 1.4542,\ c_1 = frac4{frac1{1.5}+frac1{1.4142}+frac1{1.3333}+frac1{1.5811}} approx 1.4512,\ d_1 = rootof{frac{1.5^2+1.4142^2+1.3333^2+1.5811^2}4} approx 1.4601.$$
The further calculation of the sequences should be clear. It can be seen that they converge to the same number, approximately $1.45568889$.
Challenge
Given two positive real numbers, $a$ and $b$, calculate their Mean mean $M_M(a,b)$.
Test cases
1 1 => 1
1 2 => 1.45568889
100 200 => 145.568889
2.71 3.14 => 2.92103713
0.57 1.78 => 1.0848205
1.61 2.41 => 1.98965438
0.01 100 => 6.7483058
This is code-golf, so the shortest code wins!
code-golf math
$endgroup$
$begingroup$
Sandbox link
$endgroup$
– someone
8 hours ago
$begingroup$
Somewhat related: Calculate the Arithmetic–Geometric Mean
$endgroup$
– user202729
2 hours ago
add a comment |
$begingroup$
disclaimer: the Mean mean is made up by me
Define the arithmetic mean of $n$ numbers as
$$M_1(x_1,...,x_n)=frac{x_1+x_2+...+x_n}{n}$$
Define the geometric mean of $n$ numbers as
$$M_0(x_1,...,x_n)=root{n}of{x_1x_2...x_n}$$
Define the harmonic mean of $n$ numbers as
$$M_{-1}(x_1,...,x_n)=frac{n}{frac{1}{x_2} + frac{1}{x_2} + ... + frac{1}{x_n}}$$
Define the quadratic mean of $n$ numbers as
$$M_2(x_1,...,x_n)=rootof{frac{x_1^2+x_2^2+...+x_n^2}{n}}$$
The Mean mean ($M_M$) is defined as follows:
Define four sequences ($a_k, b_k, c_k, d_k$) as $$a_0=M_1(x_1,...,x_n),\b_0=M_0(x_1,...,x_n),\c_0=M_{-1}(x_1,...,x_n),\d_0=M_2(x_1,...,x_n),\
a_{k+1}=M_1(a_k,b_k,c_k,d_k),\b_{k+1}=M_0(a_k,b_k,c_k,d_k),\c_{k+1}=M_{-1}(a_k,b_k,c_k,d_k),\d_{k+1}=M_2(a_k,b_k,c_k,d_k)$$
All four sequences converge to the same number, $M_M(x_1,x_2,...,x_n)$.
Example
The Mean mean of 1 and 2 is calculated as follows: start with $$a_0 = (1+2)/2 = 1.5, b_0 = rootof{1 * 2} = rootof2 approx 1.4142,\ c_0 = frac2{frac1{1}+frac1{2}} = frac4{3} approx 1.3333, d_0 = rootof{frac{1^2+2^2}2} = rootof{frac5{2}} approx 1.5811.$$
Then
$$a_1 = frac{1.5+1.4142+1.3333+1.5811}4 approx 1.4571,\ b_1 = root^4of{1.5*1.4142*1.3333*1.5811} approx 1.4542,\ c_1 = frac4{frac1{1.5}+frac1{1.4142}+frac1{1.3333}+frac1{1.5811}} approx 1.4512,\ d_1 = rootof{frac{1.5^2+1.4142^2+1.3333^2+1.5811^2}4} approx 1.4601.$$
The further calculation of the sequences should be clear. It can be seen that they converge to the same number, approximately $1.45568889$.
Challenge
Given two positive real numbers, $a$ and $b$, calculate their Mean mean $M_M(a,b)$.
Test cases
1 1 => 1
1 2 => 1.45568889
100 200 => 145.568889
2.71 3.14 => 2.92103713
0.57 1.78 => 1.0848205
1.61 2.41 => 1.98965438
0.01 100 => 6.7483058
This is code-golf, so the shortest code wins!
code-golf math
$endgroup$
disclaimer: the Mean mean is made up by me
Define the arithmetic mean of $n$ numbers as
$$M_1(x_1,...,x_n)=frac{x_1+x_2+...+x_n}{n}$$
Define the geometric mean of $n$ numbers as
$$M_0(x_1,...,x_n)=root{n}of{x_1x_2...x_n}$$
Define the harmonic mean of $n$ numbers as
$$M_{-1}(x_1,...,x_n)=frac{n}{frac{1}{x_2} + frac{1}{x_2} + ... + frac{1}{x_n}}$$
Define the quadratic mean of $n$ numbers as
$$M_2(x_1,...,x_n)=rootof{frac{x_1^2+x_2^2+...+x_n^2}{n}}$$
The Mean mean ($M_M$) is defined as follows:
Define four sequences ($a_k, b_k, c_k, d_k$) as $$a_0=M_1(x_1,...,x_n),\b_0=M_0(x_1,...,x_n),\c_0=M_{-1}(x_1,...,x_n),\d_0=M_2(x_1,...,x_n),\
a_{k+1}=M_1(a_k,b_k,c_k,d_k),\b_{k+1}=M_0(a_k,b_k,c_k,d_k),\c_{k+1}=M_{-1}(a_k,b_k,c_k,d_k),\d_{k+1}=M_2(a_k,b_k,c_k,d_k)$$
All four sequences converge to the same number, $M_M(x_1,x_2,...,x_n)$.
Example
The Mean mean of 1 and 2 is calculated as follows: start with $$a_0 = (1+2)/2 = 1.5, b_0 = rootof{1 * 2} = rootof2 approx 1.4142,\ c_0 = frac2{frac1{1}+frac1{2}} = frac4{3} approx 1.3333, d_0 = rootof{frac{1^2+2^2}2} = rootof{frac5{2}} approx 1.5811.$$
Then
$$a_1 = frac{1.5+1.4142+1.3333+1.5811}4 approx 1.4571,\ b_1 = root^4of{1.5*1.4142*1.3333*1.5811} approx 1.4542,\ c_1 = frac4{frac1{1.5}+frac1{1.4142}+frac1{1.3333}+frac1{1.5811}} approx 1.4512,\ d_1 = rootof{frac{1.5^2+1.4142^2+1.3333^2+1.5811^2}4} approx 1.4601.$$
The further calculation of the sequences should be clear. It can be seen that they converge to the same number, approximately $1.45568889$.
Challenge
Given two positive real numbers, $a$ and $b$, calculate their Mean mean $M_M(a,b)$.
Test cases
1 1 => 1
1 2 => 1.45568889
100 200 => 145.568889
2.71 3.14 => 2.92103713
0.57 1.78 => 1.0848205
1.61 2.41 => 1.98965438
0.01 100 => 6.7483058
This is code-golf, so the shortest code wins!
code-golf math
code-golf math
edited 40 mins ago
Jonathan Allan
53.5k535172
53.5k535172
asked 8 hours ago
someonesomeone
557418
557418
$begingroup$
Sandbox link
$endgroup$
– someone
8 hours ago
$begingroup$
Somewhat related: Calculate the Arithmetic–Geometric Mean
$endgroup$
– user202729
2 hours ago
add a comment |
$begingroup$
Sandbox link
$endgroup$
– someone
8 hours ago
$begingroup$
Somewhat related: Calculate the Arithmetic–Geometric Mean
$endgroup$
– user202729
2 hours ago
$begingroup$
Sandbox link
$endgroup$
– someone
8 hours ago
$begingroup$
Sandbox link
$endgroup$
– someone
8 hours ago
$begingroup$
Somewhat related: Calculate the Arithmetic–Geometric Mean
$endgroup$
– user202729
2 hours ago
$begingroup$
Somewhat related: Calculate the Arithmetic–Geometric Mean
$endgroup$
– user202729
2 hours ago
add a comment |
5 Answers
5
active
oldest
votes
$begingroup$
Wolfram Language (Mathematica), 77 bytes
#&@@N@Nest[{Mean@#,GeometricMean@#,HarmonicMean@#,RootMeanSquare@#}&,{##},9]&
Try it online!
$endgroup$
add a comment |
$begingroup$
Charcoal, 40 bytes
W‹⌊θ⌈θ≔⟦∕ΣθLθXΠθ∕¹Lθ∕LθΣ∕¹θ₂∕ΣXθ²Lθ⟧θI⊟θ
Try it online! Link is to verbose version of code. Takes input as an array of numbers. Explanation:
W‹⌊θ⌈θ
Repeat while the array contains different values...
≔⟦....⟧θ
... replace the array with a list of values:
∕ΣθLθ
... the mean...
XΠθ∕¹Lθ
... the geometric mean...
∕LθΣ∕¹θ
... the harmonic mean...
₂∕ΣXθ²Lθ
... and the root mean square.
I⊟θ
Cast an element of the array to string and implicitly print it.
$endgroup$
add a comment |
$begingroup$
Jelly, 25 bytes
Æm
Ç;ÆlÇÆeƊ;²Ç½Ɗ;İÇİƊµÐLḢ
Try it online!
$endgroup$
$begingroup$
I am fairly bad at Jelly, but could something similar toP*İL
work for the geometric mean?
$endgroup$
– someone
1 hour ago
$begingroup$
@someone it would need to beP*Lİ$
so wouldn’t save bytes. It would mean I could bringÆm
back down a line without costing bytes, but I quite like the fact each one currently has an arithmetic mean at its core.
$endgroup$
– Nick Kennedy
1 hour ago
add a comment |
$begingroup$
J, 34 bytes
(31 as an expression without the assignment to variable f
)
f=:1{(^.z,%z,*:z,[z=:(+/%#)&.:)^:_
Try it online!
For functions a
and b
, a &.: b
("a under b" (related challenge)) is equivalent to (b inv) a b
-- apply b, then a, then inverse of b. In this case, geometric/harmonic/quadratic mean is the arithmetic mean "under" logarithm, inversion, and square respectively.
$endgroup$
add a comment |
$begingroup$
Jelly, 24 bytes
;µ*Ɱ-;ؽ¤©Æm*İɼ;P½½ƊµÐLḢ
Try it online!
$endgroup$
add a comment |
StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["\$", "\$"]]);
});
});
}, "mathjax-editing");
StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "200"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fcodegolf.stackexchange.com%2fquestions%2f182460%2fcalculate-the-mean-mean-of-two-numbers%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
5 Answers
5
active
oldest
votes
5 Answers
5
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
Wolfram Language (Mathematica), 77 bytes
#&@@N@Nest[{Mean@#,GeometricMean@#,HarmonicMean@#,RootMeanSquare@#}&,{##},9]&
Try it online!
$endgroup$
add a comment |
$begingroup$
Wolfram Language (Mathematica), 77 bytes
#&@@N@Nest[{Mean@#,GeometricMean@#,HarmonicMean@#,RootMeanSquare@#}&,{##},9]&
Try it online!
$endgroup$
add a comment |
$begingroup$
Wolfram Language (Mathematica), 77 bytes
#&@@N@Nest[{Mean@#,GeometricMean@#,HarmonicMean@#,RootMeanSquare@#}&,{##},9]&
Try it online!
$endgroup$
Wolfram Language (Mathematica), 77 bytes
#&@@N@Nest[{Mean@#,GeometricMean@#,HarmonicMean@#,RootMeanSquare@#}&,{##},9]&
Try it online!
answered 7 hours ago
J42161217J42161217
13.6k21252
13.6k21252
add a comment |
add a comment |
$begingroup$
Charcoal, 40 bytes
W‹⌊θ⌈θ≔⟦∕ΣθLθXΠθ∕¹Lθ∕LθΣ∕¹θ₂∕ΣXθ²Lθ⟧θI⊟θ
Try it online! Link is to verbose version of code. Takes input as an array of numbers. Explanation:
W‹⌊θ⌈θ
Repeat while the array contains different values...
≔⟦....⟧θ
... replace the array with a list of values:
∕ΣθLθ
... the mean...
XΠθ∕¹Lθ
... the geometric mean...
∕LθΣ∕¹θ
... the harmonic mean...
₂∕ΣXθ²Lθ
... and the root mean square.
I⊟θ
Cast an element of the array to string and implicitly print it.
$endgroup$
add a comment |
$begingroup$
Charcoal, 40 bytes
W‹⌊θ⌈θ≔⟦∕ΣθLθXΠθ∕¹Lθ∕LθΣ∕¹θ₂∕ΣXθ²Lθ⟧θI⊟θ
Try it online! Link is to verbose version of code. Takes input as an array of numbers. Explanation:
W‹⌊θ⌈θ
Repeat while the array contains different values...
≔⟦....⟧θ
... replace the array with a list of values:
∕ΣθLθ
... the mean...
XΠθ∕¹Lθ
... the geometric mean...
∕LθΣ∕¹θ
... the harmonic mean...
₂∕ΣXθ²Lθ
... and the root mean square.
I⊟θ
Cast an element of the array to string and implicitly print it.
$endgroup$
add a comment |
$begingroup$
Charcoal, 40 bytes
W‹⌊θ⌈θ≔⟦∕ΣθLθXΠθ∕¹Lθ∕LθΣ∕¹θ₂∕ΣXθ²Lθ⟧θI⊟θ
Try it online! Link is to verbose version of code. Takes input as an array of numbers. Explanation:
W‹⌊θ⌈θ
Repeat while the array contains different values...
≔⟦....⟧θ
... replace the array with a list of values:
∕ΣθLθ
... the mean...
XΠθ∕¹Lθ
... the geometric mean...
∕LθΣ∕¹θ
... the harmonic mean...
₂∕ΣXθ²Lθ
... and the root mean square.
I⊟θ
Cast an element of the array to string and implicitly print it.
$endgroup$
Charcoal, 40 bytes
W‹⌊θ⌈θ≔⟦∕ΣθLθXΠθ∕¹Lθ∕LθΣ∕¹θ₂∕ΣXθ²Lθ⟧θI⊟θ
Try it online! Link is to verbose version of code. Takes input as an array of numbers. Explanation:
W‹⌊θ⌈θ
Repeat while the array contains different values...
≔⟦....⟧θ
... replace the array with a list of values:
∕ΣθLθ
... the mean...
XΠθ∕¹Lθ
... the geometric mean...
∕LθΣ∕¹θ
... the harmonic mean...
₂∕ΣXθ²Lθ
... and the root mean square.
I⊟θ
Cast an element of the array to string and implicitly print it.
answered 7 hours ago
NeilNeil
82.2k745178
82.2k745178
add a comment |
add a comment |
$begingroup$
Jelly, 25 bytes
Æm
Ç;ÆlÇÆeƊ;²Ç½Ɗ;İÇİƊµÐLḢ
Try it online!
$endgroup$
$begingroup$
I am fairly bad at Jelly, but could something similar toP*İL
work for the geometric mean?
$endgroup$
– someone
1 hour ago
$begingroup$
@someone it would need to beP*Lİ$
so wouldn’t save bytes. It would mean I could bringÆm
back down a line without costing bytes, but I quite like the fact each one currently has an arithmetic mean at its core.
$endgroup$
– Nick Kennedy
1 hour ago
add a comment |
$begingroup$
Jelly, 25 bytes
Æm
Ç;ÆlÇÆeƊ;²Ç½Ɗ;İÇİƊµÐLḢ
Try it online!
$endgroup$
$begingroup$
I am fairly bad at Jelly, but could something similar toP*İL
work for the geometric mean?
$endgroup$
– someone
1 hour ago
$begingroup$
@someone it would need to beP*Lİ$
so wouldn’t save bytes. It would mean I could bringÆm
back down a line without costing bytes, but I quite like the fact each one currently has an arithmetic mean at its core.
$endgroup$
– Nick Kennedy
1 hour ago
add a comment |
$begingroup$
Jelly, 25 bytes
Æm
Ç;ÆlÇÆeƊ;²Ç½Ɗ;İÇİƊµÐLḢ
Try it online!
$endgroup$
Jelly, 25 bytes
Æm
Ç;ÆlÇÆeƊ;²Ç½Ɗ;İÇİƊµÐLḢ
Try it online!
edited 1 hour ago
answered 2 hours ago
Nick KennedyNick Kennedy
1,16649
1,16649
$begingroup$
I am fairly bad at Jelly, but could something similar toP*İL
work for the geometric mean?
$endgroup$
– someone
1 hour ago
$begingroup$
@someone it would need to beP*Lİ$
so wouldn’t save bytes. It would mean I could bringÆm
back down a line without costing bytes, but I quite like the fact each one currently has an arithmetic mean at its core.
$endgroup$
– Nick Kennedy
1 hour ago
add a comment |
$begingroup$
I am fairly bad at Jelly, but could something similar toP*İL
work for the geometric mean?
$endgroup$
– someone
1 hour ago
$begingroup$
@someone it would need to beP*Lİ$
so wouldn’t save bytes. It would mean I could bringÆm
back down a line without costing bytes, but I quite like the fact each one currently has an arithmetic mean at its core.
$endgroup$
– Nick Kennedy
1 hour ago
$begingroup$
I am fairly bad at Jelly, but could something similar to
P*İL
work for the geometric mean?$endgroup$
– someone
1 hour ago
$begingroup$
I am fairly bad at Jelly, but could something similar to
P*İL
work for the geometric mean?$endgroup$
– someone
1 hour ago
$begingroup$
@someone it would need to be
P*Lİ$
so wouldn’t save bytes. It would mean I could bring Æm
back down a line without costing bytes, but I quite like the fact each one currently has an arithmetic mean at its core.$endgroup$
– Nick Kennedy
1 hour ago
$begingroup$
@someone it would need to be
P*Lİ$
so wouldn’t save bytes. It would mean I could bring Æm
back down a line without costing bytes, but I quite like the fact each one currently has an arithmetic mean at its core.$endgroup$
– Nick Kennedy
1 hour ago
add a comment |
$begingroup$
J, 34 bytes
(31 as an expression without the assignment to variable f
)
f=:1{(^.z,%z,*:z,[z=:(+/%#)&.:)^:_
Try it online!
For functions a
and b
, a &.: b
("a under b" (related challenge)) is equivalent to (b inv) a b
-- apply b, then a, then inverse of b. In this case, geometric/harmonic/quadratic mean is the arithmetic mean "under" logarithm, inversion, and square respectively.
$endgroup$
add a comment |
$begingroup$
J, 34 bytes
(31 as an expression without the assignment to variable f
)
f=:1{(^.z,%z,*:z,[z=:(+/%#)&.:)^:_
Try it online!
For functions a
and b
, a &.: b
("a under b" (related challenge)) is equivalent to (b inv) a b
-- apply b, then a, then inverse of b. In this case, geometric/harmonic/quadratic mean is the arithmetic mean "under" logarithm, inversion, and square respectively.
$endgroup$
add a comment |
$begingroup$
J, 34 bytes
(31 as an expression without the assignment to variable f
)
f=:1{(^.z,%z,*:z,[z=:(+/%#)&.:)^:_
Try it online!
For functions a
and b
, a &.: b
("a under b" (related challenge)) is equivalent to (b inv) a b
-- apply b, then a, then inverse of b. In this case, geometric/harmonic/quadratic mean is the arithmetic mean "under" logarithm, inversion, and square respectively.
$endgroup$
J, 34 bytes
(31 as an expression without the assignment to variable f
)
f=:1{(^.z,%z,*:z,[z=:(+/%#)&.:)^:_
Try it online!
For functions a
and b
, a &.: b
("a under b" (related challenge)) is equivalent to (b inv) a b
-- apply b, then a, then inverse of b. In this case, geometric/harmonic/quadratic mean is the arithmetic mean "under" logarithm, inversion, and square respectively.
edited 1 hour ago
answered 2 hours ago
user202729user202729
14.1k12553
14.1k12553
add a comment |
add a comment |
$begingroup$
Jelly, 24 bytes
;µ*Ɱ-;ؽ¤©Æm*İɼ;P½½ƊµÐLḢ
Try it online!
$endgroup$
add a comment |
$begingroup$
Jelly, 24 bytes
;µ*Ɱ-;ؽ¤©Æm*İɼ;P½½ƊµÐLḢ
Try it online!
$endgroup$
add a comment |
$begingroup$
Jelly, 24 bytes
;µ*Ɱ-;ؽ¤©Æm*İɼ;P½½ƊµÐLḢ
Try it online!
$endgroup$
Jelly, 24 bytes
;µ*Ɱ-;ؽ¤©Æm*İɼ;P½½ƊµÐLḢ
Try it online!
answered 49 mins ago
Erik the OutgolferErik the Outgolfer
32.9k429106
32.9k429106
add a comment |
add a comment |
If this is an answer to a challenge…
…Be sure to follow the challenge specification. However, please refrain from exploiting obvious loopholes. Answers abusing any of the standard loopholes are considered invalid. If you think a specification is unclear or underspecified, comment on the question instead.
…Try to optimize your score. For instance, answers to code-golf challenges should attempt to be as short as possible. You can always include a readable version of the code in addition to the competitive one.
Explanations of your answer make it more interesting to read and are very much encouraged.…Include a short header which indicates the language(s) of your code and its score, as defined by the challenge.
More generally…
…Please make sure to answer the question and provide sufficient detail.
…Avoid asking for help, clarification or responding to other answers (use comments instead).
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fcodegolf.stackexchange.com%2fquestions%2f182460%2fcalculate-the-mean-mean-of-two-numbers%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
$begingroup$
Sandbox link
$endgroup$
– someone
8 hours ago
$begingroup$
Somewhat related: Calculate the Arithmetic–Geometric Mean
$endgroup$
– user202729
2 hours ago