ExcelApplication supports all math, string, boolean, time, statisti=
cal, database, lookup and reference formulas or functions that are part of =
Excel. ExcelWriter does not calculate formulas at run-time; all formulas ar=
e calculated when the workbook is opened in Excel.
## Example

## Code Sample

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To insert a formula in a cell, use the propertyCell.Formula. Begin the f= ormula string with =3D, as you would when entering a formula in Microsoft E= xcel:

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sheet1.Cells["A25"].Formula =3D "=3DSUM(A4:A24)&q= uot;;=20

ExcelWriter allows you to use values from a different sheet when assigni= ng a formula to a cell, as in the following examples:

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sheet1.Cells[5,3].Formula =3D "=3DSUM(Sheet1!A1:A3,Sheet3!A= 1:A5)";=20

The property Cell.Name returns a cell's Excel-style name (e.g., "B5= "). This property can be useful if you want to build a formula string = using row and column indexes, rather than cell names, for example:

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String formula =3D "=3DSUM(" + sheet1.Cells[3, 1].Name= + ":" + sheet1.Cells[23, 1].Name + ")"; sheet1.Cells[24, 1].Formula =3D formula;=20

Here is an example that demonstrates how to use Formulas with ExcelAppli= cation:

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//--- Create ExcelApplication, a Workbook, and a Worksheet ExcelApplication xlw =3D new ExcelApplication(); Workbook wb =3D xlw.Create(ExcelApplication.FileFormat.Xlsx); Worksheet sheet1 =3D wb.Worksheets[0]; //--- Write some values into cells for the //--- formulas to compute sheet1.Cells["A1"].Value =3D 1; sheet1.Cells["A2"].Value =3D 2; sheet1.Cells["A3"].Value =3D 3; //--- Write a formula into a cell //--- Formula will be calculated //--- when opened in Excel sheet1.Cells["A4"].Formula =3D "=3DSUM(A1:A3)"; //--- Save the workbook xlw.Save(wb, "Generated.xlsx");=20

This sample shows many of the core features of ExcelApplication, includi= ng the use of formulas.