Talk:Abelian sandpile model: Difference between revisions
→Incorrect .PPM File created by C code.: new section
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rotated 3 times by 90° around the origin.</pre>
== A more readable Python solution. ==
This solution is more interactive, as it can also be used in imports on a Python console; plus, it is more readable.
<lang python>
from os import system, name
from time import sleep
def clear():
if name == 'nt':
_ = system('cls')
else: _ = system('clear')
def exit():
import sys
clear()
sys.exit()
def make_area(x, y):
area = [[0]*x for _ in range(y)]
return area
def make_sandpile(area, loc, height):
loc=list(n-1 for n in loc)
x, y = loc
try: area[y][x]+=height
except IndexError: pass
def run(area, by_frame=False):
def run_frame():
for y_index, group in enumerate(area):
y = y_index+1
for x_index, height in enumerate(group):
x = x_index+1
if height < 4: continue
else:
make_sandpile(area, (x+1, y), 1)
make_sandpile(area, (x, y+1), 1)
if x_index-1 >= 0:
make_sandpile(area, (x-1, y), 1)
if y_index-1 >= 0:
make_sandpile(area, (x, y-1), 1)
make_sandpile(area, (x, y), -4)
while any([any([pile>=4 for pile in group]) for group in area]):
if by_frame:
clear()
run_frame()
if by_frame:
show_area(area); sleep(.05)
def show_area(area):
display = [' '.join([str(item) if item else ' ' for item in group])
for group in area]
[print(i) for i in display]
clear()
if __name__ == '__main__':
area = make_area(10, 10)
print('\nBefore:')
show_area(area)
make_sandpile(area, (5, 5), 64); run(area)
print('\nAfter:')
show_area(area)
</lang>
Output:
<lang>
Before:
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
After:
0 0 0 0 0 0 0 0 0 0
0 0 0 1 2 1 0 0 0 0
0 0 2 2 2 2 2 0 0 0
0 1 2 2 2 2 2 1 0 0
0 2 2 2 0 2 2 2 0 0
0 1 2 2 2 2 2 1 0 0
0 0 2 2 2 2 2 0 0 0
0 0 0 1 2 1 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
</lang>
> You can just add your Python draft as an additional variant. As the Rosetta Code landing page puts it: 'to aid a person with a grounding in one approach to a problem in learning another'. The goal is to provide comparative insight rather than to construct any claim to exclusive canonicity [[User:Hout|Hout]] ([[User talk:Hout|talk]]) 21:53, 15 January 2020 (UTC)
Thanks for the information, I have added my code underneath the original.
== Incorrect .PPM File created by C code. ==
The current C code uses directly code directly copied from ppm Bitmap Writing page.
This consequently leads to a useless .ppm image created.
The following lines of code need to be replaced:
for(i=0;i<sandPileEdge;i++){
:for(j=0;j<sandPileEdge;j++){
::colour[0] = (sandPile[i][j] + i)%256;
::colour[1] = (sandPile[i][j] + j)%256;
::colour[2] = (sandPile[i][j] + i*j)%256;
:;fwrite(colour,1,3,fp);
:}
}
with these to get an image similar in style to the images on the wikipedia page, however any different combination of RGB values will serve.
for(i=0;i<sandPileEdge;i++){
:for(j=0;j<sandPileEdge;j++){
::if (sandPile[i][j] == 0){
:::colour[0] = 0;
:::colour[1] = 0;
:::colour[2] = 0;
::} else if (sandPile[i][j] == 1){
:::colour[0] = 0;
:::colour[1] = 255;
:::colour[2] = 0;
::} else if (sandPile[i][j] == 2){
:::colour[0] = 255;
:::colour[1] = 0;
:::colour[2] = 255;
::} else if (sandPile[i][j] == 3){
:::colour[0] = 255;
:::colour[1] = 215;
:::colour[2] = 0;
::};
::fwrite(colour,1,3,fp);
:};
};
[[User:BlackHorse|BlackHorse]] ([[User talk:BlackHorse|talk]])
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