Erone.py

"""
/***************************************************************************
Name                 : Erone https://it.wikipedia.org/wiki/Formula_di_Erone
Description          : Calcolo superficie PoligonZ da file CSV (XYZ)
Date                 : 25 - marzo - 2016
copyright            : (C) 2016 by Salvatore Fiandaca
email                : pigrecoinfinito@gmail.com

 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
"""

def lungh (x1,y1,z1,x2,y2,z2):                            #funzione lunghezza
    dx,dy,dz= x1-x2, y1-y2, z1-z2
    return (dx**2+dy**2+dz**2)**0.5,(dx**2+dy**2)**0.5

def Erone (a,b,c):                                 #funzione formula di Erone
    p = (a+b+c)/2.0
    return (p*(p-a)*(p-b)*(p-c))**0.5

# =============== importo il file CSV e creo lista coords ===================
import csv
with open ('triangoli3D.csv') as csvfile: 
    readCSV = csv.reader(csvfile, delimiter=',')
    coords=[]                                                     #creo liste
    for row in readCSV:                                         #popolo lista
        coords+=row
        
# ========= calcolo lunghezze lati triangolo e creazione liste ==============     
lista_3D,lista_2D = [],[]                                         #creo liste
for i in range (0,len(coords)-3,3):
    x1,y1,z1=eval(coords [i]),eval(coords[i+1]),eval(coords[i+2])
    x2,y2,z2=eval(coords [i+3]),eval(coords[i+4]),eval(coords[i+5])
    lun3D,lun2D =lungh (x1,y1,z1,x2,y2,z2)              #lunghezza lati 3D/2D
    lista_3D+=[lun3D]                         #popolo lista lunghezze lati 3D
    lista_2D+=[lun2D]                         #popolo lista lunghezze lati 2D
    
# ================= calcolo elementi per formula di Erone ===================
sup3D,sup2D = 0,0 
for j in range (0, len(lista_3D)-2,4):
    a,b,c= lista_3D [j],lista_3D [j+1],lista_3D [j+2]
    a2,b2,c2 = lista_2D [j],lista_2D [j+1],lista_2D [j+2]
    Erone_3D,Erone_2D= Erone (a,b,c),Erone (a2,b2,c2)       #formula di Erone
    sup3D+=Erone_3D
    sup2D+=Erone_2D
# ========================== stampa risultati ===============================   
print "*==================*===================*"
print sup3D,'mq Area 3D\n'
print sup2D,'mq Area 2D\n'
print sup3D-sup2D,'mq differenza Area 3D-2D\n'
print round((sup3D-sup2D)/sup3D*100,3),'%'
print "<+++++++++++++++pigreco++++++++++++++++>"