Min and Max of a list of Associations











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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







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  • 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
    1 hour ago















up vote
3
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







share|improve this question









New contributor




Professor Williams is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
















  • 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
    1 hour ago













up vote
3
down vote

favorite









up vote
3
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







share|improve this question









New contributor




Professor Williams is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











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






share|improve this question









New contributor




Professor Williams is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











share|improve this question









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edited 1 hour ago









C. E.

49.1k395197




49.1k395197






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asked 2 hours ago









Professor Williams

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Professor Williams is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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  • 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
    1 hour ago














  • 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
    1 hour ago








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
1 hour ago




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
1 hour ago










2 Answers
2






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up vote
4
down vote













How about



a = {

    <|"a" -> 4, "b" -> 9, "c" -> 15|>,

    <|"a" -> 21, "b" -> 11, "c" -> 1|>,

    <|"a" -> 12, "b" -> 3, "c" -> 21|>

};



Merge[a, Apply[Min]]



(*<|"a" -> 4, "b" -> 3, "c" -> 1|>*)



Merge[a, Apply[Max]]



(*<|"a" -> 21, "b" -> 11, "c" -> 21|>*)





share|improve this answer





















  • You don't need Apply.
    – Kuba♦
    47 mins ago


















up vote
2
down vote













Random`Private`MapThreadMin[x]

Random`Private`MapThreadMax[x]



<|"a" -> 4, "b" -> 3, "c" -> 1|>



<|"a" -> 21, "b" -> 11, "c" -> 21|>







share|improve this answer





















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    2 Answers
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    2 Answers
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    up vote
    4
    down vote













    How about



    a = {
    
    <|"a" -> 4, "b" -> 9, "c" -> 15|>,
    
    <|"a" -> 21, "b" -> 11, "c" -> 1|>,
    
    <|"a" -> 12, "b" -> 3, "c" -> 21|>
    
};
    

    
Merge[a, Apply[Min]]
    

    
(*<|"a" -> 4, "b" -> 3, "c" -> 1|>*)
    

    
Merge[a, Apply[Max]]
    

    
(*<|"a" -> 21, "b" -> 11, "c" -> 21|>*)





    share|improve this answer





















    • You don't need Apply.
      – Kuba♦
      47 mins ago















    up vote
    4
    down vote













    How about



    a = {
    
    <|"a" -> 4, "b" -> 9, "c" -> 15|>,
    
    <|"a" -> 21, "b" -> 11, "c" -> 1|>,
    
    <|"a" -> 12, "b" -> 3, "c" -> 21|>
    
};
    

    
Merge[a, Apply[Min]]
    

    
(*<|"a" -> 4, "b" -> 3, "c" -> 1|>*)
    

    
Merge[a, Apply[Max]]
    

    
(*<|"a" -> 21, "b" -> 11, "c" -> 21|>*)





    share|improve this answer





















    • You don't need Apply.
      – Kuba♦
      47 mins ago













    up vote
    4
    down vote










    up vote
    4
    down vote









    How about



    a = {
    
    <|"a" -> 4, "b" -> 9, "c" -> 15|>,
    
    <|"a" -> 21, "b" -> 11, "c" -> 1|>,
    
    <|"a" -> 12, "b" -> 3, "c" -> 21|>
    
};
    

    
Merge[a, Apply[Min]]
    

    
(*<|"a" -> 4, "b" -> 3, "c" -> 1|>*)
    

    
Merge[a, Apply[Max]]
    

    
(*<|"a" -> 21, "b" -> 11, "c" -> 21|>*)





    share|improve this answer












    How about



    a = {
    
    <|"a" -> 4, "b" -> 9, "c" -> 15|>,
    
    <|"a" -> 21, "b" -> 11, "c" -> 1|>,
    
    <|"a" -> 12, "b" -> 3, "c" -> 21|>
    
};
    

    
Merge[a, Apply[Min]]
    

    
(*<|"a" -> 4, "b" -> 3, "c" -> 1|>*)
    

    
Merge[a, Apply[Max]]
    

    
(*<|"a" -> 21, "b" -> 11, "c" -> 21|>*)






    share|improve this answer












    share|improve this answer



    share|improve this answer










    answered 1 hour ago









    Shredderroy

    1,3331014




    1,3331014












    • You don't need Apply.
      – Kuba♦
      47 mins ago


















    • You don't need Apply.
      – Kuba♦
      47 mins ago
















    You don't need Apply.
    – Kuba♦
    47 mins ago




    You don't need Apply.
    – Kuba♦
    47 mins ago










    up vote
    2
    down vote













    Random`Private`MapThreadMin[x]
    
Random`Private`MapThreadMax[x]



    <|"a" -> 4, "b" -> 3, "c" -> 1|>



    <|"a" -> 21, "b" -> 11, "c" -> 21|>







    share|improve this answer

























      up vote
      2
      down vote













      Random`Private`MapThreadMin[x]
      
Random`Private`MapThreadMax[x]



      <|"a" -> 4, "b" -> 3, "c" -> 1|>



      <|"a" -> 21, "b" -> 11, "c" -> 21|>







      share|improve this answer























        up vote
        2
        down vote










        up vote
        2
        down vote









        Random`Private`MapThreadMin[x]
        
Random`Private`MapThreadMax[x]



        <|"a" -> 4, "b" -> 3, "c" -> 1|>



        <|"a" -> 21, "b" -> 11, "c" -> 21|>







        share|improve this answer












        Random`Private`MapThreadMin[x]
        
Random`Private`MapThreadMax[x]



        <|"a" -> 4, "b" -> 3, "c" -> 1|>



        <|"a" -> 21, "b" -> 11, "c" -> 21|>








        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered 1 hour ago









        Henrik Schumacher

        46.5k466133




        46.5k466133






















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