Spreadsheet

A spreadsheet is a software for the interactive input and processing of numeric and alphanumeric data in tabular form. In many cases, it also allows the graphical representation of the results in different display forms.

The screen window of the software is divided into rows and columns. Depending on the program or operating concept called this area, for example, worksheet, worksheet or spreadsheet. Each cell of the table can be a constant (number, text, date, time ... ) or contain a formula. For the formulas usually numerous library functions are available. The formulas can use values from other cells.

Automatic recalculation of formulas

If you change the referenced cell to a formula, the software normally only updates the displayed value of the formula cell automatically, if necessary, but only on request.

Formula cells may refer to formula cells. Using this principle complicated calculation procedures can be clearly presented with many associated partial results.

Office applications

Using spreadsheets to computing applications can be listed (about wage scales, accounting data, individual statistical values) clearly, edit, share, save and reload without (as in the early days of computers) data tables need to be machined by using a programming language or running program.

A typical application of spreadsheets is the calculation of financial models and conducting simulations. The software shows the impact of changes of individual parameters at once.

Today in the office spreadsheets but are also often used as a simple substitute for real database tables. The leaves then contain no formulas or calculations are limited to simple summations over columns or rows.

Scientific Applications

In solving challenging mathematical problems, the spreadsheets provide valuable help and sometimes contribute significantly to the solution. It is helpful that calculated from tables very simple graphics can be created that show immediately any change in the selected cells. As a rule, used for such problems, but rather a computer algebra system.

In some fully worked examples from the measurement technique can be seen that the solution of a polynomial with subsequent piecewise linearization without much knowledge of mathematics is possible.
Spreadsheet is excellent, very easy to demonstrate the influence of parameters. Example: How do the zeros of a 3rd degree equation change with variation of the quadratic component?
With a spreadsheet you must be able not differentiate, to find out what you have to do so in the picture of the " high point" of the function

Interest and loan calculations are clear and meaningful. With the " Goal Seek " can be determined quickly, how high the interest rate must be in order for the capital after seven years ...
For some physical tasks like motion with air resistance, there is no "closed" solutions - with spreadsheet and graphics you see the solution after a few minutes.
The solution of differential equations for damped oscillations or for tasks of celestial mechanics can be solved almost intuitive.
The air resistance of a projectile always opposes the direction of the velocity and therefore constantly changing its direction. The deviations of the actual trajectory from the parabolic trajectory can be quite substantial and difficult "closed form " predictable. With spreadsheet can solve the problem with relatively simple means.
During free fall of a parachutist or Meteors, complex problems such as changes in the effective braking surface or changes in air density with numerical methods the spreadsheet can be edited.

History

The first software for spreadsheet was created in 1979 under the name of Dan Bricklin VisiCalc for the Apple II. VisiCalc was the first commercially useful computer program whose operation did not require any programming language. This made out of the apple, which was hitherto somewhat used by hobbyists and hobby, a computer for business applications. VisiCalc was adapted to many different computer models, including Apple III, TRS -80 Model 3, TRS -80 model 2, Commodore PET CBM -80, HP 125, Atari 800 and 1981 IBM PC. VisiCalc was introduced in 1983 by the company under Lotus Mitch Kapor for the PC developed to Lotus 1-2-3. The first program, which allowed three-dimensional spreadsheet with pages, rows, and columns was Boeing Calc, developed by the Computer Department of the aircraft manufacturer Boeing.

From Borland comes in 1987 developed Quattro Pro, which was later sold in 1994 to Novell and Corel. From the Microsoft Multiplan spreadsheet programs come ( for CP / M and MS- DOS ) and Excel ( for Mac 1985/Windows 1987). In the GNU project, the program Gnumeric is developed under GNOME. Also, the office suite OpenOffice.org includes a spreadsheet Calc; as KDE KOffice KSpread.

End of the 1980s, Lotus tried to put Improv new standards for spreadsheets. Instead of just numbers, views of the data - such as in graph or table form - to collect and formulas in a single worksheet, these concepts should be dealt with separately. The tables contain only the pure raw data, data series could be given an identifier (such as " number " or " Unit Price "). Formulas are entered in a separate program area, where the data not by row and column number referred to, but by the identifier ( " Total = Quantity * Unit Price "). In addition, it allowed Improv also similar records into groups (such as monthly sales in the group "2007" and "2008" ). Although initially developed for Improv killer application on NeXT systems, it could not prevail on other systems. Many concepts of Improv can be found today in modern spreadsheet programs (such as data grouping, which is reacted with pivot tables ).

Online spreadsheets

The development of technologies such as Ajax and XUL led to the creation of spreadsheets, are no longer visible, as is usually on a workstation, but on a local remote server: online spreadsheets. This allows work groups work together on documents, the individual user can be away from each other spatially.

Overview of some programs with spreadsheet

GeoCalc ( spreadsheet for GEOS )
Gnumeric ( part of GNOME Office )
KSpread (part of KOffice )
LibreOffice Calc
Lotus 1-2-3
Lotus Symphony
Microsoft Excel ( part of Microsoft Office )
Numbers ( for Mac OS X)
OpenOffice Calc
Org -mode ( Emacs )
PlanMaker
Quattro Pro
StarOffice StarCalc
SuperCalc
VisiCalc
Wingz (ca. 1990)