# Notes for Excel Users

If you have previously used legacy applications such as Microsoft's Excel spreadsheet, you already know most of what you need to get started with Siag. However, Siag is not an Excel emulator, and it is good to be aware of some of the differences.

## Operators

In formulas, Excel uses ^ for exponentiation. Siag has a syntax that is modeled after the C programming language. This means among other things that ^ is used for bitwise xor. To get exponentiation, use ** instead (this does not come from C).

### Example

In Excel, 2^3 evaluates to 8. In Siag, you must use 2**3 to get the same result, as 2^3 yields 1.

Another difference is that Siag has many more operators.

## Functions

Siag has hundreds of predefined functions. Many of those have Excel equivalents, but not all. In the function reference, those functions which are Excel compatible are marked as such.

## Extension Language

Excel has Visual Basic. The primary extension language in Siag is Scheme, which allows you to define new functions in a straightforward way - functions which can then be used directly in your documents.

Siag can also use other extension languages.

## File Formats

The best way to move files from Excel to Siag is this:

1. Load the file in Excel
2. Save the file using Lotus 1-2-3 format (.wk1)
3. Load the file in Siag

If the procedure above is not possible (say, you have a file in .xls format but no access to Excel), it is possible to load the file anyway using Siag's .xls support. Be aware, though, that doing this will preserve less information.