list index out of range in a np array

Question

i am making a simulator and i need every pixel of the pygame screen to be an int so i have some data like a pixel may be like 10000000 the first digit is the indicator that the pixel is loaded the second is if the pixel is explored and goes on. while creating the main city pixels i need to let the pixel know that it is occupied so i want to update the in to 11011010 while i do that it throws this error

Here the code

## Simple Python port - You need: pip install pygame. Note the code here is not efficient but it's made to be educational and easy
import numpy as np
import pygame
import random

sims = []
window_size = 600
pix = 10000000+np.zeros((window_size,window_size))
pygame.init()
window = pygame.display.set_mode((window_size, window_size))
###
green= 1
red = 2
blue= 3
yellow=4
magenta=5
cyan= 6
white=7
###
def draw(surface, x, y, color, size):
    for i in range(0, size):
        pygame.draw.line(surface, color, (x, y - 1), (x, y + 2), abs(size))

def px(x, y, c):
    return {"x": x, "y": y, "vx": 0, "vy": 0, "color": c}

def randomxy():
    return round(random.random() * window_size)

def simdoms():
    tx,ty = randomxy(), randomxy()
    print(pix[[ty],[tx]]+1)# here it runs ok while having the same tx and ty (stands for temp x)
    print(tx,ty)
    pix[[ty][tx]] = 11011010
    green= px(tx,ty,(0,255,0))
    tx, ty = randomxy(), randomxy()
    red = px(tx,ty,(255,0,0))
    pix[[ty-1][tx-1]]=11012010
    tx, ty = randomxy(), randomxy()
    blue= px(tx,ty,(0,10,255))
    pix[[ty-1][tx-1]]=11013010
    tx, ty = randomxy(), randomxy()
    yellow= px(tx,ty,(255, 196, 0))
    pix[[ty-1][tx-1]]=11014010
    tx, ty = randomxy(), randomxy()
    magenta= px(tx,ty,(242, 0, 202))
    pix[[ty-1][tx-1]]=11015010
    tx, ty = randomxy(), randomxy()
    cyan= px(tx,ty,(0, 255, 195))
    pix[[ty-1][tx-1]]=11016010
    tx, ty = randomxy(), randomxy()
    white= px(tx,ty,(255,255,255))
    pix[[ty-1][tx-1]]=11017010
    sims.append(green,red,blue,yellow,magenta,cyan,white)

print (pix)
simdoms()
run = True
while run:
    window.fill(0)
    for i in range(len(sims)):
        draw(window, sims[i]["x"], sims[i]["y"], sims[i]["color"], 3)

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False

    pygame.display.flip()
pygame.quit()
exit()

J_H · Answer

Here is an MRE.

You wrote

pix[[ty][tx]] = 11011010

You want

>>> pix = np.zeros((4, 6))
>>> ty, tx = 0, 3
>>>
>>> pix[ty, tx] = 11011010
>>>
>>> pix
array([[       0.,        0.,        0., 11011010.,        0.,        0.],
       [       0.,        0.,        0.,        0.,        0.,        0.],
       [       0.,        0.,        0.,        0.,        0.,        0.],
       [       0.,        0.,        0.,        0.,        0.,        0.]])

user95mw · Answer

The main issue of your code is, as already mentioned also in the another answer that you need to insert a ',' in your indexing doing this at multiple lines:

pix[[ty-1],[tx-1]]

The missing comma has caused the primary error. The next change you should do in your code is to change assigning colors to the sims list:

sims.extend([green,red,blue,yellow,magenta,cyan,white])

And to avoid indexing problems best change to:

return round(random.random() * (window_size-1))

because indices are counting from zero (you need -1).

With this changes the pygame window starts and looks like this:

There could be some changes done to your code to shorten it using a color table (as probably intended from the begin, but not implemented). Below the entire code with the full range of changes implementing animation and a limitation of displayed frames in order to prevent the CPU from overheating in a not paused while loop. Check it out, adjust the screen size to your desktop size and enjoy the animation (adjust the density of colored points with REPS, frame rate with FPS) in FULLSCREEN mode:

import numpy as np
import pygame
import random
FPS   = 15
REPS  = 250
CLOCK = pygame.time.Clock()
WINDOW_WIDTH  = 1920
WINDOW_HEIGHT = 1080
pix = 10000000+np.zeros((WINDOW_HEIGHT, WINDOW_WIDTH))
pygame.init()
window = pygame.display.set_mode((WINDOW_WIDTH, WINDOW_HEIGHT), pygame.FULLSCREEN)
###
dct_colors = { 
    'green'  : ((0,255,0)    , 11011010 ),
    'red'    : ((255,10,0)   , 11012010 ),
    'blue'   : ((0,0,255)    , 11013010 ),
    'yellow' : ((255,196,0)  , 11014010 ),
    'magenta': ((242, 0, 202), 11015010 ),
    'cyan'   : ((0, 255, 195), 11016010 ),
    'white'  : ((255,255,255), 11017010 ), 
}
###                          ,  )
def draw(surface, x, y, color, size):
    for i in range(0, size):
        pygame.draw.line(surface, color, (x, y), (x+3, y+3), abs(size))
def px(x, y, c):
    return {"x": x, "y": y, "vx": 0, "vy": 0, "color": c}
def randomx():
    return round(random.random() * (WINDOW_WIDTH-4))
def randomy():
    return round(random.random() * (WINDOW_HEIGHT-4))
def simdoms():
    global sims
    for color, coding in dct_colors.values():
        for reps in range(REPS):
            tx,ty = randomx(), randomy()
            pix[ty,tx] = coding
            sims.append(px(tx,ty,color))

run = True
while run:
    window.fill(0)
    sims = []
    simdoms()
    for i in range(len(sims)):
        draw(window, sims[i]["x"], sims[i]["y"], sims[i]["color"], 11)
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False
    pygame.display.flip()
    CLOCK.tick(FPS)

pygame.quit()
exit()

list index out of range in a np array

2 Answers