#!/usr/bin/python3
# -*- coding: UTF-8 -*-
# filename: port_of_second_program.py
# rev. date/time: 03-30-13-0834 hrs.
# by Mr. Cantlin.
# Line 1 above is traditionally called a "shebang" line in Python.
# The #! symbols are the reason for the name.
# The # does not start a comment line in this first line.
# There should be no white space in the shebang line.
# The shebang tells the OS where to find the Python files.
# /usr/bin/python3 is where Python is installed
# on the Bulldogmath server.
# It is not needed when you are running programs from IDLE.
# ****************************************************
# A pair of vectors below to use for testing. See Ex. 3 Pg. 230
# Vector 1 = (13.8, 40.2 degrees)
# Vector 2 = (20.9, 164.6 degrees)
# Resultant Vector - Rectangular Form = (-9.6, 14.5)
# Resultant Vector - Polar Form = (17.4, 123.6 degrees)
# All text references are from "Trigonometry with Applications"
# By Wesner and Mahler, 3rd Ed. 1994, ISBN 0-697-12292-1
# ****************************************************
# **************************************************************
# Install CGI support and math support.
# The Python script is run as a CGI program.
# CGI=Common Gateway Interface, used for many scripting languages.
# Most Linux servers have a /cgi-bin/ folder for these programs.
# This .py program will be changed to .cgi program to run.
# The Python interpreter on the server is smart enough to
# still know it is a Python program. Prob. from the shebang line.
# Python needs to install several CGI realted modules.
# **************************************************************
# **************************************************************
# Intall modules Python needs for this program. Don't forget "math".
import math
import cgi
import cgitb
cgitb.enable() # enable debugging
# **************************************************************
# **************************************************************
# Define and initialize all variables
# Use 0.0 to define as Floating Point. "anything" to define as strings.
# The input received from the hlml form will be as strings (_s added to these..
vector1_magnitude = 0.0
vector1_angle = 0.0
vector2_magnitude = 0.0
vector2_angle = 0.0
vector1_magnitude_s = "input_string"
vector1_angle_s = "input_string"
vector2_magnitude_s = "input_string"
vector2_angle_s = "input_string"
vector1_x = 0.0
vector1_y = 0.0
vector2_x = 0.0
vector2_y = 0.0
vector_sum_x = 0.0
vector_sum_y = 0.0
vector_sum_magnitude = 0.0
vector_sum_angle = 0.0
# **************************************************************
# **************************************************************
# Print to HTML requires this setup - it has THREE sections.
# Section 1: Two Lines Separate this from Section 2 with blank line
print("Content-Type: text/html") # HTML is following
print() # blank line, end of headers
# **************************************************************
# **************************************************************
# Section 2: Start Main HTML Output i.e. html framework
print("")
print("Mr. C. Add Two Vectors")
print ("")
# **************************************************************
# **************************************************************
# Read the Form Input. Convert text input to decimal form.
# Use cgi.escape to stip any html characters = improved security.
form = cgi.FieldStorage()
vector1_magnitude_s = cgi.escape(form["vector1_magnitude_s"].value, quote=True)
vector1_angle_s = cgi.escape(form["vector1_angle_s"].value, quote=True)
vector2_magnitude_s = cgi.escape(form["vector2_magnitude_s"].value, quote=True)
vector2_angle_s = cgi.escape(form["vector2_angle_s"].value, quote=True)
vector1_magnitude = float(vector1_magnitude_s)
vector1_angle = float(vector1_angle_s)
vector2_magnitude = float(vector2_magnitude_s)
vector2_angle = float(vector2_angle_s)
# **************************************************************
# ****************************************************
# Find the x and y components of the input vectors
# Since the math function works only in radians
# convert degrees to radians by multiplying by pi/180
# Python Gotcha, before you use any math() function,
# you have to import the math module :-(. See above, it
# seems like good practice to import all the modules in one place.
vector1_x = vector1_magnitude * math.cos(vector1_angle*math.pi/180)
vector2_x = vector2_magnitude * math.cos(vector2_angle*math.pi/180)
vector1_y = vector1_magnitude * math.sin(vector1_angle*math.pi/180)
vector2_y = vector2_magnitude * math.sin(vector2_angle*math.pi/180)
# ****************************************************
# ****************************************************
# Add the x components and y components to get the
# sum of the vectors in rectangular form.
vector_sum_x = vector1_x + vector2_x
vector_sum_y = vector1_y + vector2_y
# ****************************************************
# ****************************************************
# Convert the vector sum from rectangular to polar form.
# Use the atan2(y,x) function to ensure the angle returned
# is in the proper Quadrant. Warning-two arguments: y is first!
vector_sum_magnitude = math.sqrt(math.pow(vector_sum_x,2)+math.pow(vector_sum_y,2))
vector_sum_angle = math.atan2(vector_sum_y,vector_sum_x)
vector_sum_angle = vector_sum_angle * (180/math.pi)
# ****************************************************
# **************************************************************
# Display Results:
print("Results: Adding Two Vectors
")
print("Vector 1 Magnitude:", vector1_magnitude,"
")
print("Vector 1 Angle:", vector1_angle, " degrees")
print("
Vector 2 Magnitude:", vector2_magnitude,"
")
print("Vector 2 Angle:", vector2_angle, " degrees")
print("
Vector Sum in Rectangular Form: ","(",vector_sum_x,",",vector_sum_y,")")
print("
Vector Sum in Polar Form: ","(",vector_sum_magnitude,",",vector_sum_angle,"degrees",")","")
# **************************************************************
# **************************************************************
# Section 3: End Main HTML Output i.e. html framework
# End of the HTML section.
print ("")