6.1.4 Cylindrical stent structure

Finally the full pattern is translated over the stent radius in Z-direction and transformed to the cylindrical stent structure by a coordinate transformation with the Z-coordinates as distance , the X-coordinates as angle $\theta$ and the Y-coordinates as height . The scale()-operator rescales the stent structure to the correct circumference and length. The resulting stent geometry is depicted in Figure 6.5.

        # fold it into a cylinder
        self.F = F.translate([0.,0.,r]).cylindrical(dir=
		[2,0,1],scale=[1.,360./(nx*dx),p/nx/dy])
	  self.ny = ny

**Figure 6.5:** Creation of the cylindrical stent structure ((a) iso and (b) right view).

In addition to the stent initialization, the DoubleHelixStent class script contains a function all() representing the complete stent Formex. Consequently, the DoubleHelixStent class has four attributes: the Formices cell1, cell2 and all; and the number .

    def all(self):
        """Return the Formex with all bar elements."""
        return self.F