PositionSmallest

✖
`PositionSmallest`

✖

PositionSmallest[list]

gives the positions of the numerically smallest value in list.

✖

PositionSmallest[list,n]

gives the positions of the first n smallest values.

✖

PositionSmallest[list,n,orderfun]

gives the positions of the n smallest values in list as determined by orderfun.

Details

PositionSmallest by default compares values by numerical magnitude, returning the list of positions of the smallest value or n smallest values.
PositionSmallest[list] gives a single list for the smallest value.
PositionSmallest[list,n] gives a list of n sublists for the n smallest values, or as many as are available if fewer than n.
PositionSmallest expects all objects to be comparable with one another, based on the ordering function.

Examples

open allclose all

Basic Examples (2)Summary of the most common use cases

Find positions of the smallest value in a list:

In[1]:=1

✖

https://wolfram.com/xid/0bnh6n42e6y4m-fye26i

Out[1]=1

Get lists of positions for the three smallest values:

In[1]:=1

✖

https://wolfram.com/xid/0bnh6n42e6y4m-i3l6hj

Out[1]=1

Scope (6)Survey of the scope of standard use cases

Find positions of the two smallest values in an association:

In[1]:=1

✖

https://wolfram.com/xid/0bnh6n42e6y4m-diccrh

Out[1]=1

PositionSmallest works with arbitrary numeric values:

In[1]:=1

✖

https://wolfram.com/xid/0bnh6n42e6y4m-3dwb7v

Out[1]=1

PositionSmallest can work with orderings of non-numeric data:

In[1]:=1

✖

https://wolfram.com/xid/0bnh6n42e6y4m-j9ubu2

Out[1]=1

PositionSmallest uses numeric ordering by default:

In[1]:=1

✖

https://wolfram.com/xid/0bnh6n42e6y4m-ixmoen

Out[1]=1

Instead use canonical ordering:

In[2]:=2

✖

https://wolfram.com/xid/0bnh6n42e6y4m-5skp60

Out[2]=2

PositionSmallest works on lists of Quantity expressions:

In[1]:=1

✖

https://wolfram.com/xid/0bnh6n42e6y4m-uidkau

Out[1]=1

In[2]:=2

✖

https://wolfram.com/xid/0bnh6n42e6y4m-6zv4dw

Out[2]=2

PositionSmallest works on lists of DateObject expressions:

In[1]:=1

✖

https://wolfram.com/xid/0bnh6n42e6y4m-fdqisq

Out[1]=1

In[2]:=2

✖

https://wolfram.com/xid/0bnh6n42e6y4m-ff2ija

Out[2]=2

Properties & Relations (4)Properties of the function, and connections to other functions

Find positions of the smallest elements in a random list:

In[31]:=31

✖

https://wolfram.com/xid/0bnh6n42e6y4m-r2351n

Out[33]=33

Compare to results using Position and Min:

In[3]:=3

✖

https://wolfram.com/xid/0bnh6n42e6y4m-x9scg3

Out[3]=3

PositionSmallest gives positions of all the smallest elements:

In[1]:=1

✖

https://wolfram.com/xid/0bnh6n42e6y4m-9m9r0q

Out[1]=1

TakeSmallest will only give as many element positions as are requested:

In[2]:=2

✖

https://wolfram.com/xid/0bnh6n42e6y4m-edayxf

Out[2]=2

One must specify the count of minimal elements to get all positions corresponding to the smallest element using TakeSmallest:

In[3]:=3

✖

https://wolfram.com/xid/0bnh6n42e6y4m-y3ptag

Out[3]=3

Find positions of the smallest elements in a random list:

In[1]:=1

✖

https://wolfram.com/xid/0bnh6n42e6y4m-9cdsjz

Out[1]=1

One can use Ordering once the number of smallest elements is known:

In[2]:=2

✖

https://wolfram.com/xid/0bnh6n42e6y4m-osokih

Out[2]=2

Find positions of the smallest elements in a random list:

In[1]:=1

✖

https://wolfram.com/xid/0bnh6n42e6y4m-v7uwai

Out[1]=1

FindPeaks locates positions of all local minimal values:

In[2]:=2

✖

https://wolfram.com/xid/0bnh6n42e6y4m-sfupkf

Out[2]=2

Remove all peak positions that do not correspond to the global minimum value:

In[3]:=3

✖

https://wolfram.com/xid/0bnh6n42e6y4m-ra7zn7

Out[3]=3

Possible Issues (2)Common pitfalls and unexpected behavior

If fewer than the requested count of smallest values are present, PositionSmallest will give as many as are present:

In[1]:=1

✖

https://wolfram.com/xid/0bnh6n42e6y4m-4cvnvp

Out[1]=1

If the elements are not comparable, PositionSmallest will not evaluate:

In[1]:=1

✖

https://wolfram.com/xid/0bnh6n42e6y4m-kng5d2

Out[1]=1

Top