findgroups
Find groups and return group numbers
Syntax
Description
returns G
= findgroups(A
)G
,
a vector of group numbers created from the grouping variable A
.
The output argument G
contains integer values from
1 to N
, indicating N
distinct
groups for the N
unique values in A
.
For example, if A
is {'b','a','a','b'}
,
then findgroups
returns G
as [2
1 1 2]
. You can use G
to split groups
of data out of other variables. Use G
as an input
argument to splitapply
in the Split-Apply-Combine Workflow.
findgroups
treats empty character vectors
and NaN
, NaT
, and undefined
categorical values in A
as missing values and returns NaN
as
the corresponding elements of G
.
creates
group numbers from G
= findgroups(A1,...,AN)A1,...,AN
. The findgroups
function
defines groups as the unique combinations of values across A1,...,AN
.
For example, if A1
is {'a','a','b','b'}
and A2
is [0
1 0 0]
, then findgroups(A1,A2)
returns G
as [1
2 3 3]
, because the combination 'b' 0
occurs
twice.
[
also
returns the unique values for each group across G
,ID1,...,IDN] = findgroups(A1,...,AN)ID1,...,IDN
.
The values across ID1,...,IDN
define the groups.
For example, if A1
is {'a','a','b','b'}
and A2
is [0
1 0 0]
, then findgroups(A1,A2)
returns G
as [1
2 3 3]
, and ID1
and ID2
as {'a','a','b'}
and [0
1 0]
.
Examples
Input Arguments
Output Arguments
More About
Extended Capabilities
Version History
Introduced in R2015b
See Also
splitapply
| pivot
| unique
| ismember
| rowfun
| varfun
| arrayfun
| groupsummary
| discretize
| histcounts
| accumarray
| convertvars
| vartype