def gen_fig(shape, source, tool=''):
'''function to generate either a circle or line graph'''
p = Figure(plot_width=500, plot_height=500,\
title='Selected - Sample by Wave', tools = [tool])
p.title_text_color = "CadetBlue"
p.title_text_font = "helvetica"
p.xaxis.axis_label = "Wave"
p.xaxis.axis_label_text_font_size = '9pt'
p.yaxis.axis_label = "Sample Size"
p.yaxis.axis_label_text_font_size = '9pt'
if shape == 'circle':
p.circle('Years', 'SampleSize', source=source,\
size=10, color="CadetBlue", alpha=0.5)
elif shape == 'line':
p.line('Years', 'SampleSize', source=source,\
line_width=3, color='CadetBlue',line_alpha=0.7)
return p
