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DOCUMENTATION CENTER SEARCH
New to
Mathematica
?
Find your learning path
»
Mathematica
>
Core Language
>
List Manipulation
>
Elements of Lists
>
Select
>
Mathematica
>
Data Manipulation
>
Handling Arrays of Data
>
Elements of Lists
>
Select
>
Mathematica
>
Data Manipulation
>
Image Processing & Analysis
>
Basic Image Manipulation
>
Elements of Lists
>
Select
>
BUILT-IN MATHEMATICA SYMBOL
Selecting Parts of Expressions with Functions
Tutorials »
|
Cases
Take
Drop
Reap
Pick
MatchQ
StringMatchQ
See Also »
|
Conditionals
Elements of Lists
Functional Programming
Handling Arrays of Data
Language Overview
List Manipulation
Numerical Data
More About »
Select
Select
picks out all elements
of
list
for which
is
True
.
Select
picks out the first
n
elements for which
is
True
.
MORE INFORMATION
The object
list
can have any head, not necessarily
List
.
Select
can be used on
SparseArray
objects.
»
EXAMPLES
CLOSE ALL
Basic Examples
(3)
Select elements that are even:
Use a pure function to test each element:
Return only the first expression selected:
Select elements that are even:
In[1]:=
Out[1]=
Use a pure function to test each element:
In[1]:=
Out[1]=
Return only the first expression selected:
In[1]:=
Out[1]=
Scope
(1)
Select
picks out elements for which applying the criterion explicitly yields
True
:
Applying the criterion to the symbolic object
does not explicitly yield
True
:
Generalizations & Extensions
(2)
Select
works with any head, not just
List
:
Select
works with
SparseArray
objects:
The result may be a list if it is not sparse:
Applications
(7)
Select numbers up to 100 that equal 1 modulo both 3 and 5:
Select 4-tuples that read the same in reverse:
Find the first four 3×3 matrices of 0s and 1s that have determinant 1:
Select eigenvalues that lie within the unit circle:
Find built-in
Mathematica
objects whose names are less than 3 characters long:
Select numeric quantities from a product:
Find an approximation to
by finding the proportion of points that lie within a disk:
Properties & Relations
(1)
Select
is similar to
Cases
except that it uses a function instead of a pattern:
Select the lists that have sum of elements less than 10:
Use
Cases
to get the same result:
SEE ALSO
Cases
Take
Drop
Reap
Pick
MatchQ
StringMatchQ
TUTORIALS
Selecting Parts of Expressions with Functions
MORE ABOUT
Conditionals
Elements of Lists
Functional Programming
Handling Arrays of Data
Language Overview
List Manipulation
Numerical Data
RELATED LINKS
NKS|Online
(
A New Kind of Science
)
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