Jump to content

Wide and narrow data

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by Zycosi (talk | contribs) at 17:35, 21 September 2020 (Implementations: the appropriate pandas method is "pivot" not "pivot_table", while pivot_table does provide a wide format output it is for data summarization and does not preserve all of the original data). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Wide and narrow (sometimes un-stacked and stacked, or wide and tall) are terms used to describe two different presentations for tabular data.[1][2]

Wide

Wide, or unstacked data is presented with each different data variable in a separate column.

Person Age Weight Height
Bob 32 168 180
Alice 24 150 175
Steve 64 144 165

Narrow

Narrow, stacked, or long data is presented with one column containing all the values and another column listing the context of the value

Person Variable Value
Bob Age 32
Bob Weight 168
Bob Height 180
Alice Age 24
Alice Weight 150
Alice Height 175
Steve Age 64
Steve Weight 144
Steve Height 165

This is often easier to implement; addition of a new field does not require any changes to the structure of the table, however it can be harder for people to understand.

Implementations

Many statistical and data processing systems have functions to convert between these two presentations, for instance the R programming language has several packages such as the tidyr package. The pandas package in Python implements this operation as "melt" function which converts a wide table to a narrow one. The process of converting a narrow table to wide table is generally referred to as "pivoting" in the context of data transformations. The "pandas" python package provides a "pivot" method which provides for a narrow to wide transformation.

See also

References

  1. ^ Thompson, M. E. (1997), Theory of sample surveys, Chapman & Hall, London. ISBN 0-412-31780-X
  2. ^ Chantala, K. (2006) "Using STATA to Analyze data from a Sample Survey". 1-10-2001. UNC Chapel Hill, Carolina Population Center. 10-1-2006.