Functions
poseidonrna.graph(filename, num_strucs = 1, prefix = '#', color = None, color_type = None, bases = False, node_size = 10)
filename: str with .ct or .db filename
num_strucs: int number of structures to pull from file or string 'all' to graph all
prefix: str key used in ct file that is common in the name of the structure to parse rows with new structure title. Not necessary for db file
color: str varna coloring filename.
color_type: str if 'varna' will color using varnafile above
bases: boolean if True labels nucleotides.
node_size: how big the nodes are drawn
output: plot of 2D RNA structure organized by Kamada-Kawai Algorithm