A sparkline is a very small line chart, typically drawn without axes or coordinates. It presents the general shape of a variation (typically over time) in some measurement, such as temperature or stock market price, in a simple and highly condensed way. Whereas a typical chart is designed to professionally show as much data as possible, and is set off from the flow of text, sparklines are intended to be succinct, memorable, and located where they are discussed. Sparklines are small enough to be embedded in text, or several sparklines may be grouped together as elements of a small multiple.
Illustration from the "Life and Opinions of Tristram Shandy, Gentleman"
The 1888 monograph describing the 1883 eruption of the Krakatoa shows barometric signatures of the event obtained at various stations around the world in the same fashion, but in separate plates (VII & VIII), not within the text.[2]
A 1999 screenshot of an implementation of sparklines developed around January 1998. The concept was developed by interaction designer Peter Zelchenko in conversation with programmer Michael Medved, while Medved was developing the QuoteTracker application. The product was later sold to Ameritrade.[3]
In 1983, Edward Tufte had formally documented a graphical style, then called "intense continuous time-series", encouraging extreme compaction of visual information.[4] In early 1998, interface designer Peter Zelchenko introduced a feature called "inline charts", designed for the PC trading platform Medved QuoteTracker. This is believed to be the earliest known implementation of sparklines.[5] In 2006, the term sparkline itself was introduced by Edward Tufte for "small, high resolution graphics embedded in a context of words, numbers, images".[6][7] Tufte described sparklines as "data-intense, design-simple, word-sized graphics".[8]
On May 7, 2008, Microsoft employees filed a patent application for the implementation of sparklines in Microsoft Excel 2010. The application was published on November 12, 2009,[9] prompting Tufte[10] to express concern at the broad claims and lack of novelty of the patent.[11] On 23 January, 2009, MultiRacio Ltd. published an OpenOffice.org extension "EuroOffice Sparkline" to insert sparklines in OpenOffice.org Calc.[12] On March 3, 2022, LibreOffice developer Tomaž Vajngerl announced a new implementation of sparkline for LibreOffice Calc, including the support to import sparklines from OOXML Workbook format, and this is landed at 7.4 release.[13]
Usage
Sparklines are frequently used in line with text. For example:
The sparkline should be about the same height as the text around it. Tufte offers some useful design principles for the sizing of sparklines to maximize their readability.[7]
^Laurence Sterne, Life and Opinions of Tristram Shandy, Ann Ward (vol. 1–2), Dodsley (vol. 3–4), Becket & DeHondt (vol. 5–9), 1759-1767
^Symons, G. J., Judd, J. W., Strachey, S. R., Wharton, W. J. L., Evans, F. J., Russell, F. A. R., ... & Whipple, G. M. (1888). The eruption of Krakatoa: And subsequent phenomena. Trübner & Company. Plate VII
