Defining your own mathematical functions (PF)# PETSc functions (PF objects) are used to compute grid functions, element functions, etc. Beginner - Basic usage# PF PFApply PFApplyVec PFDestroy PFSet PFType Intermediate - Setting options for algorithms and data structures# PFGetType PFSetFromOptions PFSetType PFViewFromOptions Advanced - Setting more advanced options and customization# PFRegister PFRegisterAll Developer - Interfaces rarely needed by applications programmers# PFCreate PFFinalizePackage PFInitializePackage PFView Single list of manual pages# PF PFApply PFApplyVec PFCreate PFDestroy PFFinalizePackage PFGetType PFInitializePackage PFRegister PFRegisterAll PFSet PFSetFromOptions PFSetType PFType PFView PFViewFromOptions