| atlas[Frame] - declaration of frame vectors Calling Sequence: Frame(Id[j]) Parameters: Id[j] -indexed variable the frame vectors Description: The Frame procedure declares frame vectors. If E[j] is defined as a frame then vectors (n=dim) make the frame. Frame declaration is only possible if coframe has been defined (see atlas[Coframe] ). Examples: restart: with(atlas): Declare forms: Forms(e[j]=1,xi=1); ![{xi, e[j]}](prod/atlas/help/images/Frame2.gif)
Declare vectors: Vectors(X,Y,Z,E[j]); ![{X, Y, Z, E[j]}](prod/atlas/help/images/Frame3.gif)
One can not declare frame before coframe declaration: Frame(E[k]);
Error, (in Frame) coframe is undefined
Declare coframe: Coframe(e[j],j=1..n); ![{e[j]}[j = 1 .. n]](prod/atlas/help/images/Frame4.gif)
Declare frame: Frame(E[k]); ![{E[k]}[k = 1 .. n]](prod/atlas/help/images/Frame5.gif)
It is obvious that 'iota[E[i]](e[j])'=iota[E[i]](e[j]); ![iota[E[i]](e[j]) = delta[j,i]](prod/atlas/help/images/Frame6.gif)
"To basis" decomposition X=ToBasis(X); *E[l[1]],l[1] = 1 .. n)](prod/atlas/help/images/Frame7.gif)
xi=ToBasis(xi); ![xi = Sum(iota[E[l[1]]](xi)*e[l[1]],l[1] = 1 .. n)](prod/atlas/help/images/Frame8.gif)
See Also: atlas , atlas[Coframe] , atlas[ToBasis] . |