Makes initial matrix for bow and string

still need to include string, makes bow based on parabolic curve,
nodes stored in subsequent columns
length +- 748.8488mm and width 173.0785mm
~937 nodes
for angle matrix, angle for element 1 (i.e. element composed of node 1
and 2) is in column 2, so angle(1,n) corresponds to element of node(1,n)
and node(1,n-1)