Animation of a projection object use pygame - python-3.x

Question

I'm trying to make a animation of projection movement but it does't work.
Just a black window appear.
import math
import time
import pygame
V0 = int(input("please enter initial speed(m/s)"))
angle = int(input("please enter throwing angle"))
BLACK = (0, 0, 0)
WHITE = (255, 255, 255)
pygame.init()
screen = pygame.display.set_mode((400, 300))
done = False
clock = pygame.time.Clock()
while not done:
T = time.clock()
x = int(math.cos(angle)*V0*T)
y = int((math.sin(angle)*V0*T)-1/2*(9.8*T*T))
for event in pygame.event.get():
if event.type == pygame.QUIT:
done = True
screen.fill(BLACK)
pygame.draw.circle(screen, WHITE, (x, y), 5, 0)
pygame.display.flip()
clock.tick(10)
pygame.quit()
I think the problem is my formula statement, but I don't know how to fix it.

Answer 1

Read the comments. I've changed the way you calculated time and angle.
import math
import time
import pygame
V0 = int(input("please enter initial speed(m/s)"))
angle = int(input("please enter throwing angle"))
BLACK = (0, 0, 0)
WHITE = (255, 255, 255)
pygame.init()
screen = pygame.display.set_mode((400, 300))
done = False
clock = pygame.time.Clock()
T = 0 #initialize
while not done:
#T = time.clock() #don't use
x = int(math.cos(math.radians(angle))*V0*T) #use math.radians(degree). Don't just provide degrees. cos() and sin() needs input in radians
y = 300 - int((math.sin(math.radians(angle))*V0*T)-(0.5*9.8*T*T)) #looks better. projectile starts from the ground.
for event in pygame.event.get():
if event.type == pygame.QUIT:
done = True
screen.fill(BLACK)
pygame.draw.circle(screen, WHITE, (x,y), 5, 0)
milliseconds = clock.tick(60) #try this. count ms. add to s. calculate total time passed.
seconds = milliseconds / 1000.0
T += seconds
pygame.display.flip()
pygame.quit()