# Slight modification of the programs discussed in
# http://stackoverflow.com/questions/458209/is-there-a-way-to-detach-matplotlib-plots-so-that-the-computation-can-continue
# by http://stackoverflow.com/users/17160/nosklo

from matplotlib import plot, draw, show, ion
from multiprocessing import Process

def TheProblem() :
    plot([1,2,3])
    show()
    print 'This will not be printed until the plot is closed.'

def SolutionUsingDraw() :
    plot([1,2,3])
    draw()
    print 'continue computation'
    # at the end call show to ensure window won't close.
    show()

def SolutionUsingInteractiveMode() :
    ion() # enables interactive mode
    plot([1,2,3]) # result shows immediatelly (implicit draw())
    print 'continue computation'
    # at the end call show to ensure window won't close.
    show()

def SolutionUsingMultiprocessingModule() :
    def plot_graph(*args):
        for data in args:
            plot(data)
        show()
    p = Process(target=plot_graph, args=([1, 2, 3],))
    p.start()
    print 'computation continues...'
    print 'Now lets wait for the graph be closed to continue...:'
    p.join()
    # This has the overhead of launching a new process, and is sometimes harder to debug on complex scenarios, 
    # so I'd prefer the other solution (using matplotlib's nonblocking API calls)

if __name__ == '__main__':
    TheProblem()
    SolutionUsingDraw()
    SolutionUsingInteractiveMode()
    SolutionUsingMultiprocessingModule()