Origin includes all functions from the NAG Mark 26.1 Library. These functions can be easily accessed from your Origin C functions. To access any NAG function simply include the Origin C system header file OC_nag.h in your source file. All Origin C NAG header files are included in the pre-compiled system header file OC_nag.h. It is recommended to include OC_nag.h when accessing NAG functions. The NAG library categories included with Origin are listed in the following table. Click on a particular category to view available functions.