Θέμα Γ4

# STARTUP (Don't edit, typically) 
from __future__ import division
from visual import *
from physutil import *
import csv
# VISUALIZATION & GRAPH INITIALIZATION
# ===========================================
# Setup window for plotting
graph = PhysGraph(1)
# Setup Display window for visualization 
scene = display(width = 640, height = 480, background = color.black, range = 2.5, title = "VPython Test")
# Create object for visualization
ball = sphere(color = color.red, radius = 0.02)
# Create a track behind object to visualize trajectory
trail = curve(color = color.green, radius = 0.02)
# Create small sphere to mark the origin in Display window
origin = sphere(pos=vector(0,0,0), color = color.yellow, radius = 0.02)
# SYSTEM PROPERTIES and INITIAL CONDITIONS 
# ===========================================
# System Mass
#EDIT THIS (next one line): 
ball.m = 1
#Initial Conditions
#EDIT THIS (next three lines, as necessary) 
ball.pos = vector(0,0,0)
ball.vel = vector(2*sqrt(10),0,0)
t = 0 #the time when we choose to start our clock
# OTHER INITIALIZATION 
# ===========================================
#
#Timestep
#EDIT THIS (next one line, as necessary)
deltat = 0.004
#unit vector for x axis---choose "right" as direction of +x axis
vhat=ball.vel/(sqrt(ball.vel.x*ball.vel.x+ball.vel.y*ball.vel.y+ball.vel.z*ball.vel.z))
#OPTIONAL: Output model predictions to file (.csv format)
#To use, uncomment next five lines (delete leftmost # ONLY)
outputfile = open('pythonTest.csv', 'wb') # Set name of output file.
# NOTE: if the file already exists,
# it will be overwritten 
DataWriter = csv.writer(outputfile, delimiter=',', quotechar='|', quoting=csv.QUOTE_MINIMAL) # Create writer object
DataWriter.writerow(['Time (s)','Position (m)','Velocity (m/s)']) # Write column headers for time, position, and velocity
# CALCULATION LOOP(Motion Prediction and Visualization)
# ===========================================
while ball.vel.x > 0:
#Calculate Net Force
#EDIT THIS (next one line; add more lines if necessary)
Fel=-105*ball.pos
T=vector(-5,0,0)
Fnet=Fel+T
#Predict new velocity (Insert Newton's 2nd Law here)
#EDIT THIS (next one line)
ball.vel = ball.vel + (Fnet/ball.m)*deltat
#Predict new position
#EDIT THIS (next one line)
ball.pos = ball.pos + ball.vel*deltat
# advance the clock
t = t + deltat
#Update the object's track
trail.append(pos = ball.pos)
#Plot something as a function of time
#EDIT THIS (next one line, as necessary)
graph.plot(t,ball.pos.x)
#To speed up or slow down program execution
#Edit next line (larger number, faster execution)
rate(50)
#OPTIONAL: Output model predictions to file (.csv format)
#To use, uncomment next line
DataWriter.writerow([str(t),str(ball.pos.x),str(ball.vel.x)])
print(t,ball.pos.x)
#OPTIONAL: Output model predictions to file (.csv format)
#To use, uncomment next line
outputfile.close()