Spreadsheet

Modern spreadsheet software can have multiple interacting sheets and can display data either as text and numerals or in graphical form.

Such calculations as net present value or standard deviation can be applied to tabular data with a pre-programmed function in a formula.

[10] VisiCalc (1979) was the first electronic spreadsheet on a microcomputer,[11] and it helped turn the Apple II into a popular and widely used personal computer.

This electronic concept of cell references was first introduced in LANPAR (Language for Programming Arrays at Random) (co-invented by Rene Pardo and Remy Landau) and a variant used in VisiCalc and known as "A1 notation".

These batch Spreadsheets dealt primarily with the addition or subtraction of entire columns or rows (of input variables), rather than individual cells.

However, in 1995 a federal district court ruled the patent unenforceable due to inequitable conduct by the inventors during the application process.

In 1968, three former employees from the General Electric computer company headquartered in Phoenix, Arizona set out to start their own software development house.

A. Leroy Ellison, Harry N. Cantrell, and Russell E. Edwards found themselves doing a large number of calculations when making tables for the business plans that they were presenting to venture capitalists.

This program, originally conceived as a simple utility for their personal use, would turn out to be the first software product offered by the company that would become known as Capex Corporation.

It ran on an IBM mainframe and was the first application for financial planning developed with APL that completely hid the programming language from the end-user.

It loaded actual financial planning data drawn from the legacy batch system into each user's spreadsheet monthly.

An example of an early "industrial weight" spreadsheet was APLDOT, developed in 1976 at the United States Railway Association on an IBM 360/91, running at The Johns Hopkins University Applied Physics Laboratory in Laurel, MD.

The concept of spreadsheets became widely known due to VisiCalc, developed for the Apple II in 1979 by VisiCorp staff Dan Bricklin and Bob Frankston.

VisiCalc was the first spreadsheet that combined many of the essential features of modern spreadsheet applications, such as a WYSIWYG interactive user interface, automatic recalculation, status and formula lines, range copying with relative and absolute references, and formula building by selecting referenced cells.

When the professor found an error, he had to tediously erase and rewrite several sequential entries in the table, triggering Bricklin to think that he could replicate the process on a computer, using the blackboard as the model to view results of underlying formulas.

SuperCalc was a spreadsheet application published by Sorcim in 1980, and originally bundled (along with WordStar) as part of the CP/M software package included with the Osborne 1 portable computer.

It was written especially for IBM PC DOS and had improvements in speed and graphics compared to VisiCalc on the Apple II, this helped it grow in popularity.

Google Sheets originated from a web-based spreadsheet application XL2Web developed by 2Web Technologies, combined with DocVerse which enabled multiple-user online collaboration of Office documents.

In 2016 Collabora Online Calc was launched, notable in that the web based spreadsheet could be hosted and integrated into any environment without dependency on a 3rd party for authentication or maintenance.

To aid the readability of a spreadsheet, cell formatting may be conditionally applied to data; for example, a negative number may be displayed in red.

Another reason is that formulas with named variables are readily checked against the algebra they are intended to implement (they resemble Fortran expressions).

In the example below, it is assumed the sum of a column of percentages (A1 through A6) is tested for validity and an explicit message put into the adjacent right-hand cell.

A spreadsheet does not have to contain any formulas at all, in which case it could be considered merely a collection of data arranged in rows and columns (a database) like a calendar, timetable, or simple list.

The contents of the referenced cell may be accessed either on the first reference with a manual update or more recently in the case of web-based spreadsheets, as a near real-time value with a specified automatic refresh interval.

This is an example of what is perhaps its primary contribution of the earlier Javelin—the concept of traceability of a user's logic or model structure through its twelve views.

[52] EUD denotes activities or techniques in which people who are not professional developers create automated behavior and complex data objects without significant knowledge of a programming language.

A "spreadsheet program" is designed to perform general computation tasks using spatial relationships rather than time as the primary organizing principle.

Examples include the valuation of an asset, the determination of financial accounts, the calculation of medicinal doses, or the size of a load-bearing beam for structural engineering.

The risk may arise from inputting erroneous or fraudulent data values, from mistakes (or incorrect changes) within the logic of the spreadsheet or the omission of relevant updates (e.g., out of date exchange rates).

[79][80] In 2013 Thomas Herndon, a graduate student of economics at the University of Massachusetts Amherst found major coding flaws in the spreadsheet used by the economists Carmen Reinhart and Kenneth Rogoff in Growth in a Time of Debt, a very influential 2010 journal article.