[ 
https://issues.apache.org/jira/browse/ARROW-81?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Wes McKinney updated ARROW-81:
------------------------------
    Description: 
A Category (or "factor") is a dictionary-encoded array whose dictionary has 
semantic meaning. The data consists of

- An array of integer "codes"
- A child array of some other type, known as the "categories" or "levels" of 
the array. Typically there is an "ordered" boolean flag indicating whether the 
order of the categories is meaningful.

Category/factor types are used in a number of common statistical analyses. See, 
for example, 
http://www.voteview.com/R_Ordered_Logistic_or_Probit_Regression.htm. It is a 
basic requirement for Python and R, at least, as Arrow C++ consumers, to have 
this type. Separately, we should consider what is necessary to be able to 
transmit category data in IPCs -- possible an expansion of the Arrow format. 

  was:
A Category (or "factor") is a dictionary-encoded array whose dictionary has 
semantic meaning. The data consists of

- An array of integer "codes"
- A child array of some other type, known as the "categories" or "levels" of 
the array

It is a basic requirement for Python and R, at least, as Arrow C++ consumers, 
to have this type. Separately, we should consider what is necessary to be able 
to transmit category data in IPCs -- possible an expansion of the format. 


> C++: Add a Category nested type
> -------------------------------
>
>                 Key: ARROW-81
>                 URL: https://issues.apache.org/jira/browse/ARROW-81
>             Project: Apache Arrow
>          Issue Type: New Feature
>          Components: C++
>            Reporter: Wes McKinney
>            Assignee: Wes McKinney
>
> A Category (or "factor") is a dictionary-encoded array whose dictionary has 
> semantic meaning. The data consists of
> - An array of integer "codes"
> - A child array of some other type, known as the "categories" or "levels" of 
> the array. Typically there is an "ordered" boolean flag indicating whether 
> the order of the categories is meaningful.
> Category/factor types are used in a number of common statistical analyses. 
> See, for example, 
> http://www.voteview.com/R_Ordered_Logistic_or_Probit_Regression.htm. It is a 
> basic requirement for Python and R, at least, as Arrow C++ consumers, to have 
> this type. Separately, we should consider what is necessary to be able to 
> transmit category data in IPCs -- possible an expansion of the Arrow format. 



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Reply via email to