Min and Max of a list of Associations
up vote
10
down vote
favorite
I am trying to find the minimum values for all elements in a list of associations, below is an example
x = {<|"a"-> 4, "b"->9, "c"->15|>, <|"a"->21, "b"->11, "c"->1|>, <|"a"->12, "b"->3, "c"->21|>}
Required output for Min
{<|"a"-> 2, "b"->3, "c"->1|>}
Required output for Max
{<|"a"-> 21, "b"->11, "c"->15|>}
My attempt
for Max: MaximalBy[Values]@x
Result: {<|"a" -> 21, "b" -> 11, "c" -> 1|>}
for Min: MinimalBy[Values]@x
Result: {<|"a" -> 4, "b" -> 9, "c" -> 15|>}
Is there an elegant way to achieve this result?
list-manipulation associations
edited Dec 7 at 6:22
C. E.
49.3k395199
asked Dec 7 at 5:39
Professor Williams
533
add a comment |
up vote
10
down vote
favorite
I am trying to find the minimum values for all elements in a list of associations, below is an example
x = {<|"a"-> 4, "b"->9, "c"->15|>, <|"a"->21, "b"->11, "c"->1|>, <|"a"->12, "b"->3, "c"->21|>}
Required output for Min
{<|"a"-> 2, "b"->3, "c"->1|>}
Required output for Max
{<|"a"-> 21, "b"->11, "c"->15|>}
My attempt
for Max: MaximalBy[Values]@x
Result: {<|"a" -> 21, "b" -> 11, "c" -> 1|>}
for Min: MinimalBy[Values]@x
Result: {<|"a" -> 4, "b" -> 9, "c" -> 15|>}
Is there an elegant way to achieve this result?
list-manipulation associations
edited Dec 7 at 6:22
C. E.
49.3k395199
asked Dec 7 at 5:39
Professor Williams
533
1
I don't get it. How is the keyagetting the value2? That value does not appear forain any of the associations. Similarly, why is the value ofcnot equal to21in the maximal result?
– Shredderroy
Dec 7 at 6:30
add a comment |
up vote
10
down vote
favorite
up vote
10
down vote
favorite
I am trying to find the minimum values for all elements in a list of associations, below is an example
x = {<|"a"-> 4, "b"->9, "c"->15|>, <|"a"->21, "b"->11, "c"->1|>, <|"a"->12, "b"->3, "c"->21|>}
Required output for Min
{<|"a"-> 2, "b"->3, "c"->1|>}
Required output for Max
{<|"a"-> 21, "b"->11, "c"->15|>}
My attempt
for Max: MaximalBy[Values]@x
Result: {<|"a" -> 21, "b" -> 11, "c" -> 1|>}
for Min: MinimalBy[Values]@x
Result: {<|"a" -> 4, "b" -> 9, "c" -> 15|>}
Is there an elegant way to achieve this result?
list-manipulation associations
edited Dec 7 at 6:22
C. E.
49.3k395199
asked Dec 7 at 5:39
Professor Williams
533
I am trying to find the minimum values for all elements in a list of associations, below is an example
x = {<|"a"-> 4, "b"->9, "c"->15|>, <|"a"->21, "b"->11, "c"->1|>, <|"a"->12, "b"->3, "c"->21|>}
Required output for Min
{<|"a"-> 2, "b"->3, "c"->1|>}
Required output for Max
{<|"a"-> 21, "b"->11, "c"->15|>}
My attempt
for Max: MaximalBy[Values]@x
Result: {<|"a" -> 21, "b" -> 11, "c" -> 1|>}
for Min: MinimalBy[Values]@x
Result: {<|"a" -> 4, "b" -> 9, "c" -> 15|>}
Is there an elegant way to achieve this result?
list-manipulation associations
list-manipulation associations
edited Dec 7 at 6:22
C. E.
49.3k395199
asked Dec 7 at 5:39
Professor Williams
533
edited Dec 7 at 6:22
C. E.
49.3k395199
asked Dec 7 at 5:39
Professor Williams
533
edited Dec 7 at 6:22
C. E.
49.3k395199
edited Dec 7 at 6:22
C. E.
49.3k395199
edited Dec 7 at 6:22
C. E.
49.3k395199
49.3k395199
asked Dec 7 at 5:39
Professor Williams
533
asked Dec 7 at 5:39
Professor Williams
533
asked Dec 7 at 5:39
Professor Williams
533
533
1
I don't get it. How is the keyagetting the value2? That value does not appear forain any of the associations. Similarly, why is the value ofcnot equal to21in the maximal result?
– Shredderroy
Dec 7 at 6:30
add a comment |
1
I don't get it. How is the keyagetting the value2? That value does not appear forain any of the associations. Similarly, why is the value ofcnot equal to21in the maximal result?
– Shredderroy
Dec 7 at 6:30
1
1
I don't get it. How is the key
a getting the value 2? That value does not appear for a in any of the associations. Similarly, why is the value of c not equal to 21 in the maximal result?– Shredderroy
Dec 7 at 6:30
I don't get it. How is the key
a getting the value 2? That value does not appear for a in any of the associations. Similarly, why is the value of c not equal to 21 in the maximal result?– Shredderroy
Dec 7 at 6:30
add a comment |
3 Answers
3
active
oldest
votes
up vote
13
down vote
accepted
How about
a = {
<|"a" -> 4, "b" -> 9, "c" -> 15|>,
<|"a" -> 21, "b" -> 11, "c" -> 1|>,
<|"a" -> 12, "b" -> 3, "c" -> 21|>
};
Merge[a, Min]
(*<|"a" -> 4, "b" -> 3, "c" -> 1|>*)
Merge[a, Max]
(*<|"a" -> 21, "b" -> 11, "c" -> 21|>*)
EDIT
Improved, as per Kuba's suggestion.
answered Dec 7 at 6:22
Shredderroy
1,4931115
add a comment |
up vote
6
down vote
Random`Private`MapThreadMin[x]
Random`Private`MapThreadMax[x]
<|"a" -> 4, "b" -> 3, "c" -> 1|>
<|"a" -> 21, "b" -> 11, "c" -> 21|>
answered Dec 7 at 6:34
Henrik Schumacher
47.4k466134
1
is there any list out there for these "hidden" commands? Or do you happen to have a favourite list that you can share with us?
– Soner
Dec 7 at 12:33
1
A good try is always?**` ;) Honestly, I learned this trick very recently from Carl Woll. Some other good place to look for such things is What are some useful undocumented Mathematica functions?
– Henrik Schumacher
Dec 7 at 13:45
Thanks, I am checking the link right now :)
– Soner
Dec 7 at 21:35
add a comment |
up vote
1
down vote
You may use Query and MinMax.
With x as in OP.
Query[Transpose /* Map[MinMax]]@x
<|"a" -> {4, 21}, "b" -> {3, 11}, "c" -> {1, 21}|>
You can produce a more descriptive result with AssociationThread.
res = Query[Transpose /* Map[AssociationThread[{"Min", "Max"}, MinMax@#] &]]@x
<|"a" -> <|"Min" -> 4, "Max" -> 21|>,
"b" -> <|"Min" -> 3, "Max" -> 11|>,
"c" -> <|"Min" -> 1, "Max" -> 21|>|>
Which you can then access by Key with Association's syntax sugar.
res["a", "Max"]
21
Hope this helps.
answered Dec 7 at 10:30
Edmund
25.5k330100
add a comment |
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3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
13
down vote
accepted
How about
a = {
<|"a" -> 4, "b" -> 9, "c" -> 15|>,
<|"a" -> 21, "b" -> 11, "c" -> 1|>,
<|"a" -> 12, "b" -> 3, "c" -> 21|>
};
Merge[a, Min]
(*<|"a" -> 4, "b" -> 3, "c" -> 1|>*)
Merge[a, Max]
(*<|"a" -> 21, "b" -> 11, "c" -> 21|>*)
EDIT
Improved, as per Kuba's suggestion.
answered Dec 7 at 6:22
Shredderroy
1,4931115
add a comment |
up vote
13
down vote
accepted
How about
a = {
<|"a" -> 4, "b" -> 9, "c" -> 15|>,
<|"a" -> 21, "b" -> 11, "c" -> 1|>,
<|"a" -> 12, "b" -> 3, "c" -> 21|>
};
Merge[a, Min]
(*<|"a" -> 4, "b" -> 3, "c" -> 1|>*)
Merge[a, Max]
(*<|"a" -> 21, "b" -> 11, "c" -> 21|>*)
EDIT
Improved, as per Kuba's suggestion.
answered Dec 7 at 6:22
Shredderroy
1,4931115
add a comment |
up vote
13
down vote
accepted
up vote
13
down vote
accepted
How about
a = {
<|"a" -> 4, "b" -> 9, "c" -> 15|>,
<|"a" -> 21, "b" -> 11, "c" -> 1|>,
<|"a" -> 12, "b" -> 3, "c" -> 21|>
};
Merge[a, Min]
(*<|"a" -> 4, "b" -> 3, "c" -> 1|>*)
Merge[a, Max]
(*<|"a" -> 21, "b" -> 11, "c" -> 21|>*)
EDIT
Improved, as per Kuba's suggestion.
answered Dec 7 at 6:22
Shredderroy
1,4931115
How about
a = {
<|"a" -> 4, "b" -> 9, "c" -> 15|>,
<|"a" -> 21, "b" -> 11, "c" -> 1|>,
<|"a" -> 12, "b" -> 3, "c" -> 21|>
};
Merge[a, Min]
(*<|"a" -> 4, "b" -> 3, "c" -> 1|>*)
Merge[a, Max]
(*<|"a" -> 21, "b" -> 11, "c" -> 21|>*)
EDIT
Improved, as per Kuba's suggestion.
answered Dec 7 at 6:22
Shredderroy
1,4931115
edited Dec 7 at 8:30
answered Dec 7 at 6:22
Shredderroy
1,4931115
answered Dec 7 at 6:22
Shredderroy
1,4931115
answered Dec 7 at 6:22
Shredderroy
1,4931115
1,4931115
add a comment |
add a comment |
up vote
6
down vote
Random`Private`MapThreadMin[x]
Random`Private`MapThreadMax[x]
<|"a" -> 4, "b" -> 3, "c" -> 1|>
<|"a" -> 21, "b" -> 11, "c" -> 21|>
answered Dec 7 at 6:34
Henrik Schumacher
47.4k466134
1
is there any list out there for these "hidden" commands? Or do you happen to have a favourite list that you can share with us?
– Soner
Dec 7 at 12:33
1
A good try is always?**` ;) Honestly, I learned this trick very recently from Carl Woll. Some other good place to look for such things is What are some useful undocumented Mathematica functions?
– Henrik Schumacher
Dec 7 at 13:45
Thanks, I am checking the link right now :)
– Soner
Dec 7 at 21:35
add a comment |
up vote
6
down vote
Random`Private`MapThreadMin[x]
Random`Private`MapThreadMax[x]
<|"a" -> 4, "b" -> 3, "c" -> 1|>
<|"a" -> 21, "b" -> 11, "c" -> 21|>
answered Dec 7 at 6:34
Henrik Schumacher
47.4k466134
1
is there any list out there for these "hidden" commands? Or do you happen to have a favourite list that you can share with us?
– Soner
Dec 7 at 12:33
1
A good try is always?**` ;) Honestly, I learned this trick very recently from Carl Woll. Some other good place to look for such things is What are some useful undocumented Mathematica functions?
– Henrik Schumacher
Dec 7 at 13:45
Thanks, I am checking the link right now :)
– Soner
Dec 7 at 21:35
add a comment |
up vote
6
down vote
up vote
6
down vote
Random`Private`MapThreadMin[x]
Random`Private`MapThreadMax[x]
<|"a" -> 4, "b" -> 3, "c" -> 1|>
<|"a" -> 21, "b" -> 11, "c" -> 21|>
answered Dec 7 at 6:34
Henrik Schumacher
47.4k466134
Random`Private`MapThreadMin[x]
Random`Private`MapThreadMax[x]
<|"a" -> 4, "b" -> 3, "c" -> 1|>
<|"a" -> 21, "b" -> 11, "c" -> 21|>
answered Dec 7 at 6:34
Henrik Schumacher
47.4k466134
answered Dec 7 at 6:34
Henrik Schumacher
47.4k466134
answered Dec 7 at 6:34
Henrik Schumacher
47.4k466134
answered Dec 7 at 6:34
Henrik Schumacher
47.4k466134
47.4k466134
1
is there any list out there for these "hidden" commands? Or do you happen to have a favourite list that you can share with us?
– Soner
Dec 7 at 12:33
1
A good try is always?**` ;) Honestly, I learned this trick very recently from Carl Woll. Some other good place to look for such things is What are some useful undocumented Mathematica functions?
– Henrik Schumacher
Dec 7 at 13:45
Thanks, I am checking the link right now :)
– Soner
Dec 7 at 21:35
add a comment |
1
is there any list out there for these "hidden" commands? Or do you happen to have a favourite list that you can share with us?
– Soner
Dec 7 at 12:33
1
A good try is always?**` ;) Honestly, I learned this trick very recently from Carl Woll. Some other good place to look for such things is What are some useful undocumented Mathematica functions?
– Henrik Schumacher
Dec 7 at 13:45
Thanks, I am checking the link right now :)
– Soner
Dec 7 at 21:35
1
1
is there any list out there for these "hidden" commands? Or do you happen to have a favourite list that you can share with us?
– Soner
Dec 7 at 12:33
is there any list out there for these "hidden" commands? Or do you happen to have a favourite list that you can share with us?
– Soner
Dec 7 at 12:33
1
1
A good try is always
?**` ;) Honestly, I learned this trick very recently from Carl Woll. Some other good place to look for such things is What are some useful undocumented Mathematica functions?– Henrik Schumacher
Dec 7 at 13:45
A good try is always
?**` ;) Honestly, I learned this trick very recently from Carl Woll. Some other good place to look for such things is What are some useful undocumented Mathematica functions?– Henrik Schumacher
Dec 7 at 13:45
Thanks, I am checking the link right now :)
– Soner
Dec 7 at 21:35
Thanks, I am checking the link right now :)
– Soner
Dec 7 at 21:35
add a comment |
up vote
1
down vote
You may use Query and MinMax.
With x as in OP.
Query[Transpose /* Map[MinMax]]@x
<|"a" -> {4, 21}, "b" -> {3, 11}, "c" -> {1, 21}|>
You can produce a more descriptive result with AssociationThread.
res = Query[Transpose /* Map[AssociationThread[{"Min", "Max"}, MinMax@#] &]]@x
<|"a" -> <|"Min" -> 4, "Max" -> 21|>,
"b" -> <|"Min" -> 3, "Max" -> 11|>,
"c" -> <|"Min" -> 1, "Max" -> 21|>|>
Which you can then access by Key with Association's syntax sugar.
res["a", "Max"]
21
Hope this helps.
answered Dec 7 at 10:30
Edmund
25.5k330100
add a comment |
up vote
1
down vote
You may use Query and MinMax.
With x as in OP.
Query[Transpose /* Map[MinMax]]@x
<|"a" -> {4, 21}, "b" -> {3, 11}, "c" -> {1, 21}|>
You can produce a more descriptive result with AssociationThread.
res = Query[Transpose /* Map[AssociationThread[{"Min", "Max"}, MinMax@#] &]]@x
<|"a" -> <|"Min" -> 4, "Max" -> 21|>,
"b" -> <|"Min" -> 3, "Max" -> 11|>,
"c" -> <|"Min" -> 1, "Max" -> 21|>|>
Which you can then access by Key with Association's syntax sugar.
res["a", "Max"]
21
Hope this helps.
answered Dec 7 at 10:30
Edmund
25.5k330100
add a comment |
up vote
1
down vote
up vote
1
down vote
You may use Query and MinMax.
With x as in OP.
Query[Transpose /* Map[MinMax]]@x
<|"a" -> {4, 21}, "b" -> {3, 11}, "c" -> {1, 21}|>
You can produce a more descriptive result with AssociationThread.
res = Query[Transpose /* Map[AssociationThread[{"Min", "Max"}, MinMax@#] &]]@x
<|"a" -> <|"Min" -> 4, "Max" -> 21|>,
"b" -> <|"Min" -> 3, "Max" -> 11|>,
"c" -> <|"Min" -> 1, "Max" -> 21|>|>
Which you can then access by Key with Association's syntax sugar.
res["a", "Max"]
21
Hope this helps.
answered Dec 7 at 10:30
Edmund
25.5k330100
You may use Query and MinMax.
With x as in OP.
Query[Transpose /* Map[MinMax]]@x
<|"a" -> {4, 21}, "b" -> {3, 11}, "c" -> {1, 21}|>
You can produce a more descriptive result with AssociationThread.
res = Query[Transpose /* Map[AssociationThread[{"Min", "Max"}, MinMax@#] &]]@x
<|"a" -> <|"Min" -> 4, "Max" -> 21|>,
"b" -> <|"Min" -> 3, "Max" -> 11|>,
"c" -> <|"Min" -> 1, "Max" -> 21|>|>
Which you can then access by Key with Association's syntax sugar.
res["a", "Max"]
21
Hope this helps.
answered Dec 7 at 10:30
Edmund
25.5k330100
answered Dec 7 at 10:30
Edmund
25.5k330100
answered Dec 7 at 10:30
Edmund
25.5k330100
answered Dec 7 at 10:30
Edmund
25.5k330100
25.5k330100
add a comment |
add a comment |
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1
I don't get it. How is the key
agetting the value2? That value does not appear forain any of the associations. Similarly, why is the value ofcnot equal to21in the maximal result?– Shredderroy
Dec 7 at 6:30