Array ( [0] => Array ( [title] => L2A [link] => https://www.youtube.com/embed/pJrpSg13Ur8 ) [1] => Array ( [title] => L2B [link] => https://www.youtube.com/embed/2s2AN71KB5w ) ) 國立清華大學開放式課程OpenCourseWare(NTHU, OCW) - Lecture 2 | Flows and differential equations; Transformation of vector fields