> For the complete documentation index, see [llms.txt](https://excelhelp.windhamlabs.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://excelhelp.windhamlabs.com/functions/general.md).

# General

- [ISMATRIXPSD](https://excelhelp.windhamlabs.com/functions/general/ismatrixpsd.md): Verify if a matrix is positive semidefinite. Solve for the nearest positive semidefinite matrix if it is not.
- [MATRIX](https://excelhelp.windhamlabs.com/functions/general/matrix.md): Concatenate disjointed arrays in Excel column (or row)-wise into a matrix
- [XLABHELP](https://excelhelp.windhamlabs.com/functions/general/xlabhelp.md): Getting help within Excel for the Excel Lab quant library.
- [XLABINFO](https://excelhelp.windhamlabs.com/functions/general/xlabinfo.md): Retrieve information about the Excel Lab quant library installed on your workstation.
- [XLABLICENSE](https://excelhelp.windhamlabs.com/functions/general/xlablicense.md): Invoke authentication with licensing servers to enable or re-enable your use of Excel Lab.
- [RESETPASSWORD](https://excelhelp.windhamlabs.com/functions/general/resetpassword.md): Update and set a new password for your user account