Reference

All functions
DNA_plot()	Plot a DNA double helix
Moon_cake()	Draw a Moon_cake (Mid- Autumn Festival) using ggplot2
Olympic_rings()	Plot the Olympic rings
chunlian()	Draw a Chunlian (Spring Festival couplet) using ggplot2
clock()	Plot clock
convert_chr_to_matrix()	convert a character to 01 matrix
convert_img_to_matrix()	convert a imgage to 01 matrix
give_you_a_rose()	Give you a rose
life_game()	Life Game Simulation
make_LED()	make a LED screen
my_wordcloud()	Word cloud plot
pixel_plot()	Plot a pixel image
plot(<chr_mat>)	Plot a chr_mat
show_github_calendar()	Plot a github style calendar