6 8 ▁NFL ▁D raft . ▁ ▁Category : 1 9 4 5 ▁birth s ▁Category : 2 0 0 2 ▁death s ▁Category : American ▁football ▁def ensive ▁ends ▁Category : Ch icago ▁B ears ▁players ▁Category : Pe ople ▁from ▁St . ▁Matt he ws , ▁South ▁Carolina ▁Category : Play ers ▁of ▁American ▁football ▁from ▁South ▁Carolina ▁Category : S ports people ▁from ▁Columbia , ▁South ▁Carolina ▁Category : S outh ▁Carolina ▁State ▁Bul ld ogs ▁football ▁players ▁Category : W ashington ▁Red sk ins ▁players <0x0A> </s> ▁In ▁mathematics , ▁a ▁ske w ▁gradient ▁of ▁a ▁harm onic ▁function ▁over ▁a ▁simply ▁connected ▁domain ▁with ▁two ▁real ▁dimensions ▁is ▁a ▁vector ▁field ▁that ▁is ▁everywhere ▁orthogonal ▁to ▁the ▁gradient ▁of ▁the ▁function ▁and ▁that ▁has ▁the ▁same ▁magnitude ▁as ▁the ▁gradient . ▁ ▁Definition ▁The ▁ske w ▁gradient ▁can ▁be ▁defined ▁using ▁complex ▁analysis ▁and ▁the ▁C auch y – R iemann ▁equations . ▁ ▁Let ▁ ▁be ▁a ▁complex - valu ed ▁analyt ic ▁function , ▁where ▁u , v ▁are ▁real - valu ed ▁scalar ▁functions ▁of ▁the ▁real ▁variables   x ,   y . ▁ ▁A ▁ske w ▁gradient ▁is ▁defined ▁as : ▁▁▁▁ ▁and ▁from ▁the ▁C auch y – R iemann ▁equations , ▁it ▁is ▁derived ▁that ▁ ▁Properties ▁The ▁ske w ▁gradient ▁has ▁two ▁interesting ▁properties . ▁It ▁is ▁everywhere ▁orthogonal ▁to ▁the ▁gradient ▁of ▁u , ▁and ▁of ▁the ▁same ▁length : ▁ ▁References ▁▁ ▁Peter ▁Ol ver , ▁Introduction ▁to