Question

I was wondering if anyone had an idea as to why the code below does not display a graph with a line in it after the button on the GUI is pressed. I would like to create a program that executes a long list of commands after a set of data is imported by clicking a button. One of these commands would be to display the spectral data on a graph within the same window. Here is what I have so far:

# import modules that I'm using
import matplotlib
matplotlib.use('TKAgg')
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg, NavigationToolbar2TkAgg
from matplotlib.figure import Figure
import matplotlib.pyplot as pltlib
import Tkinter
from Tkinter import *
import numpy as np
import scipy as sc
#import matplotlib.pyplot as pltlib
# lmfit is imported becuase parameters are allowed to depend on each other along with bounds, etc.
from lmfit import minimize, Parameters, Minimizer



#Make object for application
class App_Window(Tkinter.Tk):
    def __init__(self,parent):
        Tkinter.Tk.__init__(self,parent)
        self.parent = parent
        self.initialize()
    def initialize(self):
        button = Tkinter.Button(self,text="Open File",command=self.OnButtonClick).pack(side=Tkinter.TOP)
        self.canvasFig=pltlib.figure(1)
        Fig = matplotlib.figure.Figure(figsize=(5,4),dpi=100)
        FigSubPlot = Fig.add_subplot(111)
        x=[]
        y=[]
        self.line1, = FigSubPlot.plot(x,y,'r-')
        self.canvas = matplotlib.backends.backend_tkagg.FigureCanvasTkAgg(Fig, master=self)
        self.canvas.show()
        self.canvas.get_tk_widget().pack(side=Tkinter.TOP, fill=Tkinter.BOTH, expand=1)
        self.canvas._tkcanvas.pack(side=Tkinter.TOP, fill=Tkinter.BOTH, expand=1)
        self.resizable(True,False)
        self.update()
    def refreshFigure(self,x,y):
        self.line1.set_xdata(x)
        self.line1.set_ydata(y)
        self.canvas.draw()
    def OnButtonClick(self):
        # file is opened here and some data is taken
        # I've just set some arrays here so it will compile alone
        x=[]
        y=[]
        for num in range(0,1000):x.append(num*.001+1)
        # just some random function is given here, the real data is a UV-Vis spectrum
        for num2 in range(0,1000):y.append(sc.math.sin(num2*.06)+sc.math.e**(num2*.001))
        X = np.array(x)
        Y = np.array(y)
        self.refreshFigure(X,Y)

if __name__ == "__main__":
    MainWindow = App_Window(None)
    MainWindow.mainloop()

Answer 1

That is because the range of xaxis & yaxis doesn’t change to new data’s range, change your refreshFigure as following:

def refreshFigure(self,x,y):
    self.line1.set_data(x,y)
    ax = self.canvas.figure.axes[0]
    ax.set_xlim(x.min(), x.max())
    ax.set_ylim(y.min(), y.max())        
    self.canvas.draw()