First version of multiprocessing

Not working

1 files changed, 107 insertions, 0 deletions

diff --git a/sem4/hpp/miniproject/multiproc.py b/sem4/hpp/miniproject/multiproc.py
new file mode 100644
index 0000000..be39326
--- /dev/null
+++ b/sem4/hpp/miniproject/multiproc.py
@@ -0,0 +1,107 @@
+#!/usr/bin/env python3
+
+import numpy as np
+import matplotlib.pyplot as plt
+import time
+import multiprocessing as mp
+from multiprocessing import RawArray
+
+# c-mesh limits
+limitre = ( -2, 1 )
+limitim = ( -1.5, 1.5 )
+
+
+def worker(gridchunk, s, step, T, l):
+    global rs
+    # Preallocate z array
+    rschunk = rs[s : s + step]
+
+    z = np.zeros(rschunk.shape)
+    print(f"rschunk.shape: {rschunk.shape}, gridchunk.shape: {gridchunk.shape}, T: {T}, l: {l}")
+
+    # Calculate ι for all complex numbers
+    for i in range(l):
+        # This will generate warnings for some of the values rising above T.
+        # Because these values are above T they are not used, thus the warnings
+        # can be ignored
+        z = z*z + gridchunk
+
+        # This will generate 1 in all the places 
+        # where z < T and zeros elsewhere
+        below = (np.abs(z) < T)
+
+        # Add this to the result
+        # Because the ones that pass T are 0 
+        # they will stop counting.
+        #
+        # If a specific z never reaches >= T its value in rs will
+        # be l
+        rschunk += below
+
+    np.divide(rschunk, l, out=rschunk)
+
+def mangel(pre, pim, T, l, workers):
+    """
+    Calculate the mangelbrot image with multiple processes
+    (pre, pim) discribes the image size. Use T and l to tune the mangelbrot
+
+    This will split the image in horizontal parts and distribute it 
+    between the workers.
+    Because the result array is row major, data will be nicely together if
+    the workers work with rows not columns.
+
+    Pre must be devisible by workers.
+
+    The result is saved in rs. Sorry couln't get numpy references through to the process as arguments
+
+    :param pre: Number of real numbers used
+    :param pim: Number of imaginary numbers
+    :param T: Mangelbrot threshold
+    :param l: Iterations
+    :param workers: Number of workers. 
+    """
+
+    # Used to calculate c-mesh
+    re = np.linspace(limitre[0], limitre[1], pre)
+    im = np.linspace(limitim[0], limitim[1], pim)
+
+    # Calculate c-mesh
+    grid = np.add.outer(re, 1j * im)
+
+    # Calculate the partition variables
+    step = int(pre / workers)
+
+
+    # Loop chunks and start the workers
+    wl = []
+    for s in range(0, pre, step):
+        gridchunk = grid[s : s + step]
+        p = mp.Process(target=worker, args=(gridchunk, s, step, T, l))
+        wl.append(p)
+        p.start()
+
+    # Wait for them to be done
+    for p in wl:
+        p.join()
+
+    return rs
+
+rs = np.full((500, 500), 0.5)
+
+start = time.time()
+arr = mangel(500, 500, 2, 100, 1)
+end = time.time()
+
+plt.imshow(arr, cmap=plt.cm.hot, vmin=0, vmax=1)
+plt.savefig("mult.png")
+
+print(f"Took {end - start} seconds")
+"""
+        p = mp.Process(target=worker, args=(rs[s:s + step], grid[s:s + step], T, l))
+        wl.append(p)
+        p.start()
+
+    # Wait for them to be done
+    for p in wl:
+        p.join()
+"""