Skip to content

Commit

Permalink
#379: Optimization by binary search of the left element on median.
Browse files Browse the repository at this point in the history
  • Loading branch information
@annoviko
annoviko committed Feb 22, 2020
1 parent 256f228 commit f88d47c
Show file tree
Hide file tree
Showing 2 changed files with 93 additions and 57 deletions.
9 changes: 5 additions & 4 deletions pyclustering/container/kdtree.py
View file
Original file line number Diff line number Diff line change
Expand Up @@ -34,7 +34,7 @@
warnings.warn("Impossible to import matplotlib (please, install 'matplotlib'), pyclustering's visualization "
"functionality is not available (details: '%s')." % str(error_instance))

from pyclustering.utils import euclidean_distance_square
from pyclustering.utils import euclidean_distance_square, find_left_element


class kdtree_visualizer:
Expand Down Expand Up @@ -357,9 +357,10 @@ def __create_tree(self, nodes, parent, depth):
# Elements could be the same around the median, but all elements that are >= to the current should
# be at the right side.
# TODO: optimize by binary search - no need to use O(n)
while median - 1 >= 0 and \
nodes[median].data[discriminator] == nodes[median - 1].data[discriminator]:
median -= 1
median = find_left_element(nodes, median, lambda n1, n2: n1.data[discriminator] < n2.data[discriminator])
# while median - 1 >= 0 and \
# nodes[median].data[discriminator] == nodes[median - 1].data[discriminator]:
# median -= 1

new_node = nodes[median]
new_node.disc = discriminator
Expand Down
141 changes: 88 additions & 53 deletions pyclustering/utils/__init__.py
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1083,72 +1083,107 @@ def draw_image_mask_segments(source, clusters, hide_axes = True):
@param[in] hide_axes (bool): If True then axes will not be displayed.
"""
if (len(clusters) == 0):
if len(clusters) == 0:
print("Warning: Nothing to draw - list of clusters is empty.")
return;
return

image_source = Image.open(source);
image_size = image_source.size;
image_source = Image.open(source)
image_size = image_source.size

# Calculate edge for confortable representation.
number_clusters = len(clusters) + 1; # show with the source image

number_cols = int(numpy.ceil(number_clusters ** 0.5));
number_rows = int(numpy.ceil(number_clusters / number_cols));
number_clusters = len(clusters) + 1 # show with the source image

number_cols = int(numpy.ceil(number_clusters ** 0.5))
number_rows = int(numpy.ceil(number_clusters / number_cols))

real_index = 0, 0;
double_indexer = True;
if ( (number_cols == 1) or (number_rows == 1) ):
real_index = 0;
double_indexer = False;
real_index = 0, 0
double_indexer = True
if (number_cols == 1) or (number_rows == 1):
real_index = 0
double_indexer = False

(fig, axarr) = plt.subplots(number_rows, number_cols);
plt.setp([ax for ax in axarr], visible = False);
(fig, axarr) = plt.subplots(number_rows, number_cols)
plt.setp([ax for ax in axarr], visible=False)

axarr[real_index].imshow(image_source, interpolation = 'none');
plt.setp(axarr[real_index], visible = True);
axarr[real_index].imshow(image_source, interpolation='none')
plt.setp(axarr[real_index], visible=True)

if (hide_axes is True):
axarr[real_index].xaxis.set_ticklabels([]);
axarr[real_index].yaxis.set_ticklabels([]);
axarr[real_index].xaxis.set_ticks_position('none');
axarr[real_index].yaxis.set_ticks_position('none');
if hide_axes is True:
axarr[real_index].xaxis.set_ticklabels([])
axarr[real_index].yaxis.set_ticklabels([])
axarr[real_index].xaxis.set_ticks_position('none')
axarr[real_index].yaxis.set_ticks_position('none')

if (double_indexer is True):
real_index = 0, 1;
if double_indexer is True:
real_index = 0, 1
else:
real_index += 1;
real_index += 1

for cluster in clusters:
stage_cluster = [(255, 255, 255)] * (image_size[0] * image_size[1]);
stage_cluster = [(255, 255, 255)] * (image_size[0] * image_size[1])
for index in cluster:
stage_cluster[index] = (0, 0, 0);
stage_cluster[index] = (0, 0, 0)

stage = array(stage_cluster, numpy.uint8);
stage = numpy.reshape(stage, (image_size[1], image_size[0]) + ((3),)); # ((3),) it's size of RGB - third dimension.
stage = array(stage_cluster, numpy.uint8)
stage = numpy.reshape(stage, (image_size[1], image_size[0]) + ((3),)) # ((3),) it's size of RGB - 3rd dimension.

image_cluster = Image.fromarray(stage, 'RGB');
image_cluster = Image.fromarray(stage, 'RGB')

axarr[real_index].imshow(image_cluster, interpolation = 'none');
plt.setp(axarr[real_index], visible = True);
axarr[real_index].imshow(image_cluster, interpolation = 'none')
plt.setp(axarr[real_index], visible = True)

if (hide_axes is True):
axarr[real_index].xaxis.set_ticklabels([]);
axarr[real_index].yaxis.set_ticklabels([]);
if hide_axes is True:
axarr[real_index].xaxis.set_ticklabels([])
axarr[real_index].yaxis.set_ticklabels([])

axarr[real_index].xaxis.set_ticks_position('none');
axarr[real_index].yaxis.set_ticks_position('none');
axarr[real_index].xaxis.set_ticks_position('none')
axarr[real_index].yaxis.set_ticks_position('none')

if (double_indexer is True):
real_index = real_index[0], real_index[1] + 1;
if (real_index[1] >= number_cols):
real_index = real_index[0] + 1, 0;
if double_indexer is True:
real_index = real_index[0], real_index[1] + 1
if real_index[1] >= number_cols:
real_index = real_index[0] + 1, 0
else:
real_index += 1;
real_index += 1


plt.show();
plt.show()


def find_left_element(sorted_data, right, comparator):
"""!
@brief Returns the element's index at the left side from the right border with the same value as the
last element in the range `sorted_data`.
@details The element at the right is considered as target to search. `sorted_data` must
be sorted collection. The complexity of the algorithm is `O(log(n))`. The
algorithm is based on the binary search algorithm.
@param[in] sorted_data: input data to find the element.
@param[in] right: the index of the right element from that search is started.
@param[in] comparator: comparison function object which returns `True` if the first argument
is less than the second.
@return The element's index at the left side from the right border with the same value as the
last element in the range `sorted_data`.
"""
if len(sorted_data) == 0:
raise ValueError("Input data is empty.")

left = 0
middle = (right - left) // 2
target = sorted_data[right]

while left < right:
if comparator(sorted_data[middle], target):
left = middle + 1
else:
right = middle

offset = (right - left) // 2
middle = left + offset

return left


def linear_sum(list_vector):
Expand All @@ -1169,7 +1204,7 @@ def linear_sum(list_vector):
linear_sum = [0] * dimension

for index_element in range(0, len(list_vector)):
if (list_representation is True):
if list_representation is True:
for index_dimension in range(0, dimension):
linear_sum[index_dimension] += list_vector[index_element][index_dimension]
else:
Expand Down Expand Up @@ -1211,7 +1246,7 @@ def list_math_subtraction(a, b):
@return (list) Results of subtraction of two lists.
"""
return [a[i] - b[i] for i in range(len(a))];
return [a[i] - b[i] for i in range(len(a))]


def list_math_substraction_number(a, b):
Expand All @@ -1225,7 +1260,7 @@ def list_math_substraction_number(a, b):
@return (list) Results of subtraction between list and number.
"""
return [a[i] - b for i in range(len(a))];
return [a[i] - b for i in range(len(a))]


def list_math_addition(a, b):
Expand All @@ -1239,7 +1274,7 @@ def list_math_addition(a, b):
@return (list) Results of addtion of two lists.
"""
return [a[i] + b[i] for i in range(len(a))];
return [a[i] + b[i] for i in range(len(a))]


def list_math_addition_number(a, b):
Expand All @@ -1253,7 +1288,7 @@ def list_math_addition_number(a, b):
@return (list) Result of addtion of two lists.
"""
return [a[i] + b for i in range(len(a))];
return [a[i] + b for i in range(len(a))]


def list_math_division_number(a, b):
Expand All @@ -1267,7 +1302,7 @@ def list_math_division_number(a, b):
@return (list) Result of division between list and number.
"""
return [a[i] / b for i in range(len(a))];
return [a[i] / b for i in range(len(a))]


def list_math_division(a, b):
Expand All @@ -1281,7 +1316,7 @@ def list_math_division(a, b):
@return (list) Result of division of two lists.
"""
return [a[i] / b[i] for i in range(len(a))];
return [a[i] / b[i] for i in range(len(a))]


def list_math_multiplication_number(a, b):
Expand All @@ -1295,7 +1330,7 @@ def list_math_multiplication_number(a, b):
@return (list) Result of division between list and number.
"""
return [a[i] * b for i in range(len(a))];
return [a[i] * b for i in range(len(a))]


def list_math_multiplication(a, b):
Expand All @@ -1309,4 +1344,4 @@ def list_math_multiplication(a, b):
@return (list) Result of multiplication of elements in two lists.
"""
return [a[i] * b[i] for i in range(len(a))];
return [a[i] * b[i] for i in range(len(a))]

0 comments on commit f88d47c

Please sign in to comment.