Extraneous Matplotlib Figure (plot in tkinter)

This is my first python project and I am trying to plot the Mandelbrot set in Matplotlib and place it into a tkinter frame. This has already been accomplished however a extraneous empty figure appears along with the GUI. This empty plot has the correct amount of tick marks while the plot in the GUI has the incorrect amount of tick marks on the plot (I cant figure out where the tick values are coming from either, but I suspect pixels). I have also searched for quite some time now on how to solve this problem to no avail. I have tried canvas.draw, messing with the methods and classes and I still cannot figure it out... The following is an excerpt of the code that will run. code specifying the display are in the method named mandelbrot_image and the MainPage class Thank you in advance.

import matplotlib
matplotlib.use("TkAgg")
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg, NavigationToolbar2TkAgg
from matplotlib.figure import Figure

import tkinter as tk
from tkinter import ttk
from tkinter import *


import numpy as np
from numba import jit

from matplotlib import pyplot as plt
from matplotlib import colors



#maths and display code derived/inspired from Jean Francois Puget 
#https://www.ibm.com/developerworks/community/blogs/jfp/entry/My_Christmas_Gift?lang=en





@jit
def mandelbrot(z,maxiter,horizon,log_horizon):
    c = z
    for n in range(maxiter):
        az = abs(z)
        if az > horizon:
            return n - np.log(np.log(az))/np.log(2) + log_horizon
        z = z*z + c
    return 0

@jit
def mandelbrot_set(xmin,xmax,ymin,ymax,width,height,maxiter):
    horizon = 2.0 ** 40
    log_horizon = np.log(np.log(horizon))/np.log(2)
    r1 = np.linspace(xmin, xmax, width)
    r2 = np.linspace(ymin, ymax, height)
    n3 = np.empty((width,height))
    for i in range(width):
        for j in range(height):
            n3[i,j] = mandelbrot(r1[i] + 1j*r2[j],maxiter,horizon, log_horizon)
    return (r1,r2,n3)




LARGE_FONT= ("Verdana", 12)

def mandelbrot_image(xmin=-2.,xmax=0.5,ymin=-1.25,ymax=1.25,width=10,height=10,\
             maxiter=1000,cmap='jet',gamma=0.3):

    dpi = 80
    img_width = dpi * width
    img_height = dpi * height
    x,y,z = mandelbrot_set(xmin,xmax,ymin,ymax,img_width,img_height,maxiter)

    fig = Figure(figsize=(width, height))
    ax = fig.add_subplot(111)

    ticks = np.arange(0,img_width,3*dpi)
    x_ticks = xmin + (xmax-xmin)*ticks/img_width
    plt.xticks(ticks, x_ticks)
    y_ticks = ymin + (ymax-ymin)*ticks/img_width
    plt.yticks(ticks, y_ticks)
    ax.set_title("The Mandelbrot set")
    norm = colors.PowerNorm(gamma)
    ax.imshow(z.T,cmap=cmap,origin='lower',norm=norm)


    return fig

class base(tk.Tk):

    def __init__(self, *args, **kwargs):

        tk.Tk.__init__(self, *args, **kwargs)

        tk.Tk.iconbitmap(self, "iconz.ico")
        tk.Tk.wm_title(self, "Mandelbrot Renderer")


        container = tk.Frame(self)
        container.pack(side="top", fill="both", expand = True)
        container.grid_rowconfigure(0, weight=1)
        container.grid_columnconfigure(0, weight=1)

        self.frames = {}

        for F in (StartPage, MainPage):

            frame = F(container, self)

            self.frames[F] = frame

            frame.grid(row=0, column=0, sticky="nsew")

        self.show_frame(StartPage)

    def show_frame(self, cont):

        frame = self.frames[cont]
        frame.tkraise()

class StartPage(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self,parent)
        label = tk.Label(self, text="Start Page", font=LARGE_FONT)
        label.pack(pady=10,padx=10)

        button = tk.Button(self, text="Lets Begin",
                    command=lambda: controller.show_frame(MainPage))
        button.pack()
class MainPage(tk.Frame):
    def getcheckvalue(self):
        print (self.mvar.get())

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        label = tk.Label(self, text="Graph Page!", font=LARGE_FONT)
        label.pack(pady=10,padx=10)

        button1 = ttk.Button(self, text="Back to Home",
                        command=lambda: controller.show_frame(StartPage))
        button1.pack()




        fig = mandelbrot_image()
        canvas = FigureCanvasTkAgg(fig, self)
        canvas.show()
        canvas.get_tk_widget().pack(side=tk.BOTTOM, fill=tk.BOTH, expand=True)

        toolbar = NavigationToolbar2TkAgg(canvas, self)
        toolbar.update()
        canvas._tkcanvas.pack(side=tk.TOP, fill=tk.BOTH, expand=True) 

app = base()
app.geometry ("800x600")
app.mainloop()