試圖從一個.txt文件

Question

我試圖找出如何計算使用在一個文本文件中的座標的線段的長度計算點之間的距離：

X,Y format (x,y,x,y,x,y,etc...)

4.5,10.0,4.5,5.7,5.5,2.5,6.5,0.3,6.8,0.0,1.0,1.0,3.5,3.5,2,5,6.0,2.0

這是我到目前爲止：

Python

# -*- coding: cp1252 -*- 
#Starter code for GIS301 Lab 2 
#GIS301Lab2Starter.py 

import math 

#----------------------------------------------------------- 
#Procedure for reading a coordinate text file 
#in x1,y1,x2,y2,… xn,yn format 
#and resulting in a list as type float 

#open file to read 
file = open(r'C:\Users\Tristan\Desktop\USB_Backup_10-4-16\2016-2017\Fall2016\SpatialDataStructures\Labs\Lab2\points.txt','r') 

#read file to string 
coordString = file.read() 
#Split coordString into list elements 
coordList = coordString.split(',') 
#convert from string to float type 
for index, item in enumerate(coordList): 
    coordList[index] = float(coordList[index]) 
file.close 
#----------------------------------------------------------- 
print (coordList)  
#add more code here 
numPoints = len(coordList)/2 
print("Number of Points") 
print (numPoints) 


x = [float(r) for r in coordList[0::2]] 
y = [float(r) for r in coordList[1::2]] 

xy = list(zip(x,y)) 


# pre-define distance and add subsequent distances 
dist = 0 
for r in coordList(len(xy)-1): 
    dist += ((xy[r][0]-xy[r+1][0])**2 + (xy[r][1]-xy[r+1][1])**2)**0.5 

print (dist) 



#for r in coordList(len(xy)-1): 
# dist += ((xy[r][0]-xy[r+1][0])**2 + (xy[r][1]-xy[r+1][1])**2)**0.5 

When I run it in PyhthonWin:

Traceback (most recent call last): 
    File "C:\Users\Tristan\Desktop\USB_Backup_10-4-16\2016-2017\Fall2016\SpatialDataStructures\Labs\Lab2\GOERSLab2.py", line 39, in <module> 
    for r in coordList(len(xy)-1): 
TypeError: 'list' object is not callable 

的方程n用於計算兩點之間的距離爲： http://i.stack.imgur.com/vOcu0.png

然後我需要將它們全部加起來！

Answer 1

從你所提供的，我沒有看到需要過度複雜這一點。假設你可以正確導入文本文件數據，並拆分它，你可以這樣做：

points = ['4.5','10.0','4.5','5.7','5.5','2.5','6.5','0.3','6.8','0.0','1.0','1.0','3.5','3.5','2','5','6.0','2.0'] 


x = [float(r) for r in points[0::2]] 
y = [float(r) for r in points[1::2]] 

# put x/y coordinates in tuples 
xy = list(zip(x,y)) 

# pre-define distance and add subsequent distances 
dist = 0 
for r in xrange(len(xy)-1): 
    dist += ((xy[r][0]-xy[r+1][0])**2 + (xy[r][1]-xy[r+1][1])**2)**0.5 

我覺得東西沿着這些路線將工作做好（你甚至不需要把座標元組，真）。這是否符合你所需要的？