使用tkinter /使用按鈕進行多次計算的牛頓方程式

Question

我是python的新手。我的問題是：我可以使用一個按鈕「估計」多少次來計算我的答案？更具體地說，該項目是將牛頓公式應用到tkinter中。如果輸入爲0，那麼估計變量文本框的計算結果爲0.如果輸入是正數，我應該能夠使用估計按鈕作爲循環多次處理該數字。我很容易使用嵌套while循環獲得最終結果。但是，試圖重複使用估計按鈕逐步進入算法似乎是不可能的。我已經嘗試了一切。最接近的我是設置我的inputVar複製我的estimateVar，但這顯然會導致邏輯錯誤，因爲輸入需要保持不變。此外，我已經嘗試設置一個全局變量的估計，但python不會允許我操縱估計，我的inputVar返回全局值。估計的初始值必須是1.如果有人有任何意見，我們將不勝感激。這裏是我的代碼

''' 
Created on Nov 11, 2015 

@author: lz206729 
''' 

from tkinter import * 



class newtonGUI(Frame): 





    def __init__(self): 
    #Sets up window 
     Frame.__init__(self) 
     self.master.title("Newton's Square") 
     self.grid(column = 0, row = 0) 

    #Label and field for number input 
     self._inputLabel = Label(self, text = "Input a positive number to square: ") 
     self._inputLabel.grid(row = 0, column = 0) 
     self._inputVar = DoubleVar() 
     self._inputEntry = Entry(self, textvariable = self._inputVar) 
     self._inputEntry.grid(row = 0, column = 1) 

    #Displays the common square root 
     self._estimateLabel = Label(self, text = "The estimate is : ") 
     self._estimateLabel.grid(row = 1, column = 0) 
     self._estimateVar = DoubleVar() 
     self._estimateEntry = Entry(self, textvariable = self._estimateVar) 
     self._estimateEntry.grid(row = 1, column = 1) 

    #Button that computes the input 
     self._estimateButton = Button(self, text = "Estimate", command = self._newtonSquare) 
     self._estimateButton.grid(row = 4, column = 0) 


    #Button that resets text boxes 
     self._resetButton = Button(self, text = "Reset", command = self._reset) 
     self._resetButton.grid(row = 4, column = 1) 





    def _newtonSquare(self): 
     tolerance = 0.000001 
     estimate = 1 
     x = self._inputVar.get() 

     if x == 0: 
      self._estimateVar.set(x/2) 
     else: 
      while True: 
       estimate = (estimate + x/estimate)/2 
       difference = abs(x - estimate **2) 
       if difference <= tolerance: 
        break 

      self._estimateVar.set(estimate) 



    def _reset(self): 
     self._inputVar.set(0) 
     self._estimateVar.set(0) 
     self._estimateButton.config(state='normal') 



def main(): 
    newtonGUI().mainloop() 
main() 

Answer 1

你的目標和問題不明確，但這裏是我認爲基於「估計按鈕步入算法增量」你想要的。

from tkinter import * 

class newtonGUI(Frame): 
    def __init__(self, master): 
     #Set up frame 
     Frame.__init__(self, master) 
     self.master.title("Newton's Squareroot") 
     self.grid(column = 0, row = 0) 

     #Label and field for number input 
     self._inputLabel = Label(self, text = "Input a positive number") 
     self._inputLabel.grid(row = 0, column = 0) 
     self._inputVar = DoubleVar() 
     self._inputVar.set(1.0) 
     self._inputEntry = Entry(self, textvariable = self._inputVar) 
     self._inputEntry.grid(row = 0, column = 1) 

     #Display the common square root 
     self._estimateLabel = Label(self, text = "Square root estimate") 
     self._estimateLabel.grid(row = 1, column = 0) 
     self._estimateVar = DoubleVar() 
     self._estimateVar.set(1.0) 
     self._estimateEntry = Label(self, textvariable = self._estimateVar) 
     self._estimateEntry.grid(row = 1, column = 1) 

     #Button that computes the input 
     self._estimateButton = Button(self, text = "Estimate", command = self._newtonSquare) 
     self._estimateButton.grid(row = 4, column = 0) 

     #Button that resets text boxes 
     self._resetButton = Button(self, text = "Reset", command = self._reset) 
     self._resetButton.grid(row = 4, column = 1) 

    def _newtonSquare(self): 
     val = self._inputVar.get() 
     est = self._estimateVar.get() 
     if val <= 0.0: 
      self._estimateVar.set(0.0) 
     else: 
      self._estimateVar.set((est + val/est)/2) 

    def _reset(self): 
     self._inputVar.set(1.0) 
     self._estimateVar.set(1.0) 

def main(): 
    root = Tk() 
    newtonGUI(root) 
    root.mainloop() 
main() 

Answer 2

謝謝你， 肯定送我正確的方向。我甚至沒有考慮將我的初始值設置爲1。起初，代碼只執行普通的平方值，所以我修改了它。再次感謝。這是最終的節目。

from tkinter import * 

class newtonGUI(Frame): 
    def __init__(self, master): 
     #Set up frame 
     Frame.__init__(self, master) 
     self.master.title("Newton's Squareroot") 
     self.grid(column = 0, row = 0) 

     #Label and field for number input 
     self._inputLabel = Label(self, text = "Input a positive number") 
     self._inputLabel.grid(row = 0, column = 0) 
     self._inputVar = DoubleVar() 
     self._inputVar.set(1.0) 
     self._inputEntry = Entry(self, textvariable = self._inputVar) 
     self._inputEntry.grid(row = 0, column = 1) 

     #Display the common square root 
     self._estimateLabel = Label(self, text = "Square root estimate") 
     self._estimateLabel.grid(row = 1, column = 0) 
     self._estimateVar = DoubleVar() 
     self._estimateVar.set(1.0) 
     self._estimateEntry = Label(self, textvariable = self._estimateVar) 
     self._estimateEntry.grid(row = 1, column = 1) 

     #Button that computes the input 
     self._estimateButton = Button(self, text = "Estimate", command = self._newtonSquare) 
     self._estimateButton.grid(row = 4, column = 0) 

     #Button that resets text boxes 
     self._resetButton = Button(self, text = "Reset", command = self._reset) 
     self._resetButton.grid(row = 4, column = 1) 

    def _newtonSquare(self): 
     value = self._inputVar.get() 
     estimate = self._estimateVar.get() 
     tolerance = 0.000001 

     if value <= 0.0: 
      self._estimateVar.set(0.0) 
     else: 
      estimate = (estimate + value/estimate)/2 
      difference = abs(value - estimate **2) 
      if difference <= tolerance: 
       self._estimateVar.set(estimate) 
       self._estimateButton.config(state = 'disabled') 
      else: 
       self._estimateVar.set(estimate) 

    def _reset(self): 
     self._inputVar.set(1.0) 
     self._estimateVar.set(1.0) 

def main(): 
    root = Tk() 
    newtonGUI(root) 
    root.mainloop() 
main()