On Wed, Dec 30, 2015 at 6:35 AM, Alan Gauld <alan.ga...@btinternet.com> wrote:
> On 30/12/15 05:55, Tom Xu wrote: > > Dear Pythoneers, > > > > I want to draw several curves in one graph, but the amount of curves is > not > > a fixed number. > > OK, But what exactly are you asking us to do? > > > My homework is below: > > --- > > import matplotlib.pyplot as plt > > import math > > > > if __name__=='__main__': > > try: > > n=int(input('how many curves? ')) > > ulist=[] > > thetalist=[] > > for i in range(n): > > ulist.append(float(input('Enter velocity: '))) > > thetalist.append(float(input('Enter angle: '))) > > except ValueError: > > print('invalid input') > > else: > > generateFr(?????) > > You need to put the call to generateFr inside a loop that > iterates n times putting successive values from ulist and > thetalist into the function. > > Also, put the function definitions above the place where you call them. Normally, the if __name__ stuff should be below your function definitions > > > def generateFr(u, theta): > > theta=math.radians(theta) > > g=9.8 > > > > tflight=2*u*math.sin(theta)/g > > intervals=frange(0, tflight, 0.001) > > x=[] > > y=[] > > for t in intervals: > > x.append(u*math.cos(theta)*t) > > y.append(u*math.sin(theta)*t - 0.5*g*t*t) > > drawgraph(x, y) > > > > def frange(start, final, increment): > > numbers=[] > > while start<final: > > numbers.append(start) > > start+=increment > > return numbers > > > > def drawgraph(x, y): > > plt.plot(x, y) > > plt.xlabel('x-coordinate') > > plt.ylabel('y-coordinate') > > plt.title('Projectile motion') > > > > -- > Alan G > Author of the Learn to Program web site > http://www.alan-g.me.uk/ > http://www.amazon.com/author/alan_gauld > Follow my photo-blog on Flickr at: > http://www.flickr.com/photos/alangauldphotos > > > _______________________________________________ > Tutor maillist - Tutor@python.org > To unsubscribe or change subscription options: > https://mail.python.org/mailman/listinfo/tutor > -- Joel Goldstick http://joelgoldstick.com/stats/birthdays _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor