The L-system is an important method of fractal generation, derived from the simulation of plant morphology and growth. It is a system of linguistic instructions consisting of several symbols It is a system of linguistic instructions consisting of a number of symbols, which are automatically executed by a computer. Some of the simpler fractals are implemented using the drawing board. We can simplify the elements of the L-system fractal into two: the initial element and the generating element, based on which "human + computer" generates the fractal. The fractal pattern is generated by the "brain + computer". The following is an example of a simple forward format LS fractal with LS pentagrams. I. L code direct translation method
1. Make the initial element AB and the generating element A-B. Make the initial element AB, scale B by 0.618 to A to get B', scale B by 0.618 to get A', scale A by 0.618 to get A', scale A by 0.618 to get A', scale B by 0.618 to get B'. Scale A to obtain A', rotate B by 108° counterclockwise from B' to obtain B'', rotate B by 108° counterclockwise from B'' to obtain B'', rotate B' by 108° counterclockwise from B'' to obtain B'', rotate B' by 108° counterclockwise from B'' to obtain B''. Rotate B' by 108° to obtain B''', and join AA'B''B'B, and B''B''' in turn to obtain the generating element as shown in the figure.
2. Iterate over the generators. First, delete the line segments in the generating element, show the initial element AB, create a new parameter n=2, and make the initial element AB to AA', A''B''', and B''B''', A'B'', B "B', B'B, B'''B'' with depth n. After hiding the initial element and the points with the apostrophe, the iteration of the initial element is shown as follows The iterative image of the initial element is shown in Fig.
3. Make a five-point shape. Make a circle with five equal points D, E, F, G and H to obtain a five-point shape DEFGH.
4. Make a LS pentagram. Select point A, B, parameter n and the iterative image of the initial element, enter the transformation menu, create a custom tool. Set parameter n to "Auto Match Objects" and use this tool to match the five edges ED, FE, GF, HG and DH in turn. The result is the LS pentagonal star.