I have written a program in python to map the random positions of points on a disc for a project. The idea is that for different numbers of points the random positions will be saved as a png for use later. The code is as follows:
def randr():#random r position
return random.random()
def randphi():#random phi position
return 2*pi*random.random()
nrange=[3,10,11,12,15,20,25,30]
for N in nrange:
rposition=[]#create a table of r positions
phiposition=[]#create a table of phi positions
rinverse=[]#create a table of 1/rij
for listcreation in range(0,N,1):#go through each charge
rposition.append(randr())#allocate a random r position
phiposition.append(randphi())#allocate a random phi position
name=N
filename = "c:/users/V/%i.png" % name
pyplot.polar(phiposition,rposition,marker='o', markersize=10,color='b',
linestyle='none')
pyplot.savefig(filename, format='png')
The problem is that when this code is run the first figure saves with 3 points but the second one saves with 13 instead of 10! This goes on for successive N
I cannot post images so you'll have to take my word for it or run the code.
Does anyone know how to overcome this?
By default, the axes are not cleared between plots, so when you plot the second plot, it adds to whatever was already plotted. To clear it, insert pyplot.cla() before your polar call.