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# Author: Andreas Christian Mueller <>
# (c) 2012
# Modified by: Paul Nechifor <>
# License: MIT
import warnings
from random import Random
import os
import re
import sys
import numpy as np
from operator import itemgetter
from PIL import Image
from PIL import ImageDraw
from PIL import ImageFont
from .query_integral_image import query_integral_image
item1 = itemgetter(1)
FONT_PATH = os.environ.get("FONT_PATH", os.path.join(os.path.dirname(__file__), "DroidSansMono.ttf"))
STOPWORDS = set([x.strip() for x in open(os.path.join(os.path.dirname(__file__),
class IntegralOccupancyMap(object):
def __init__(self, height, width, mask):
self.height = height
self.width = width
if mask is not None:
# the order of the cumsum's is important for speed ?!
self.integral = np.cumsum(np.cumsum(255 * mask, axis=1),
self.integral = np.zeros((height, width), dtype=np.uint32)
def sample_position(self, size_x, size_y, random_state):
return query_integral_image(self.integral, size_x, size_y, random_state)
def update(self, img_array, pos_x, pos_y):
partial_integral = np.cumsum(np.cumsum(img_array[pos_x:, pos_y:], axis=1),
# paste recomputed part into old image
# if x or y is zero it is a bit annoying
if pos_x > 0:
if pos_y > 0:
partial_integral += (self.integral[pos_x - 1, pos_y:]
- self.integral[pos_x - 1, pos_y - 1])
partial_integral += self.integral[pos_x - 1, pos_y:]
if pos_y > 0:
partial_integral += self.integral[pos_x:, pos_y - 1][:, np.newaxis]
self.integral[pos_x:, pos_y:] = partial_integral
def random_color_func(word=None, font_size=None, position=None,
orientation=None, font_path=None, weight=None, random_state=None, **kwargs):
"""Random hue color generation.
Default coloring method. This just picks a random hue with value 80% and
lumination 50%.
word, font_size, position, orientation : ignored.
random_state : random.Random object or None, (default=None)
If a random object is given, this is used for generating random numbers.
if random_state is None:
random_state = Random()
return "hsl(%d, 80%%, 50%%)" % random_state.randint(0, 255)
class WordCloud(object):
"""Word cloud object for generating and drawing.
font_path : string
Font path to the font that will be used (OTF or TTF).
Defaults to DroidSansMono path on a Linux machine. If you are on
another OS or don't have this font, you need to adjust this path.
width : int (default=400)
Width of the canvas.
height : int (default=200)
Height of the canvas.
ranks_only : boolean (default=False)
Only use the rank of the words, not the actual counts.
prefer_horizontal : float (default=0.90)
The ratio of times to try horizontal fitting as opposed to vertical.
mask : nd-array or None (default=None)
If not None, gives a binary mask on where to draw words. If mask is not
None, width and height will be ignored and the shape of mask will be
used instead. All white (#FF or #FFFFFF) entries will be considerd
"masked out" while other entries will be free to draw on. [This
changed in the most recent version!]
scale : float (default=1)
Scaling between computation and drawing. For large word-cloud images,
using scale instead of larger canvas size is significantly faster, but
might lead to a coarser fit for the words.
min_font_size : int (default=4)
Smallest font size to use. Will stop when there is no more room in this
font_step : int (default=1)
Step size for the font. font_step > 1 might speed up computation but
give a worse fit.
max_words : number (default=200)
The maximum number of words.
stopwords : set of strings
The words that will be eliminated.
background_color : color value (default="black")
Background color for the word cloud image.
max_font_size : int or None (default=None)
Maximum font size for the largest word. If None, height of the image is
mode: string (default="RGB")
Transparent background will be generated when mode is "RGBA" and
background_color is None.
``words_``: list of tuples (string, float)
Word tokens with associated frequency.
``layout_`` : list of tuples (string, int, (int, int), int, color))
Encodes the fitted word cloud. Encodes for each word the string, font
size, position, orientation and color.
Larger canvases with make the code significantly slower. If you need a large
word cloud, try a lower canvas size, and set the scale parameter.
The algorithm might give more weight to the ranking of the words
than their actual frequencies, depending on the ``max_font_size`` and the
scaling heuristic.
def __init__(self, font_path=None, width=400, height=200, margin=2,
ranks_only=False, prefer_horizontal=0.9, mask=None, scale=1,
color_func=random_color_func, max_words=200, min_font_size=4,
stopwords=None, random_state=None, background_color='black',
max_font_size=None, font_step=1, mode="RGB"):
if stopwords is None:
stopwords = STOPWORDS
if font_path is None:
font_path = FONT_PATH
self.font_path = font_path
self.width = width
self.height = height
self.margin = margin
self.ranks_only = ranks_only
self.prefer_horizontal = prefer_horizontal
self.mask = mask
self.scale = scale
self.color_func = color_func
self.max_words = max_words
self.stopwords = stopwords
self.min_font_size = min_font_size
self.font_step = font_step
if isinstance(random_state, int):
random_state = Random(random_state)
self.random_state = random_state
self.background_color = background_color
if max_font_size is None:
max_font_size = height
self.max_font_size = max_font_size
self.mode = mode
def fit_words(self, frequencies):
"""Create a word_cloud from words and frequencies.
Alias to generate_from_frequencies.
frequencies : array of tuples
A tuple contains the word and its frequency.
return self.generate_from_frequencies(frequencies)
def generate_from_frequencies(self, frequencies, **kwargs):
"""Create a word_cloud from words and frequencies.
frequencies : array of tuples
A tuple contains the word and its frequency.
self.kwargs = kwargs
if self.random_state is not None:
random_state = self.random_state
random_state = Random()
if len(frequencies) <= 0:
print("We need at least 1 word to plot a word cloud, got %d."
% len(frequencies))
if self.mask is not None:
mask = self.mask
width = mask.shape[1]
height = mask.shape[0]
if mask.dtype.kind == 'f':
warnings.warn("mask image should be unsigned byte between 0 and"
" 255. Got a float array")
if mask.ndim == 2:
boolean_mask = mask == 255
elif mask.ndim == 3:
# if all channels are white, mask out
boolean_mask = np.all(mask[:, :, :3] == 255, axis=-1)
raise ValueError("Got mask of invalid shape: %s" % str(mask.shape))
boolean_mask = None
height, width = self.height, self.width
occupancy = IntegralOccupancyMap(height, width, boolean_mask)
# create image
img_grey ="L", (width, height))
draw = ImageDraw.Draw(img_grey)
img_array = np.asarray(img_grey)
font_sizes, positions, orientations, colors = [], [], [], []
font_size = self.max_font_size
# start drawing grey image
for word, count in frequencies:
# alternative way to set the font size
if not self.ranks_only:
font_size = min(font_size, int(100 * np.log(count + 100)))
while True:
# try to find a position
font = ImageFont.truetype(self.font_path, font_size)
# transpose font optionally
if random_state.random() < self.prefer_horizontal:
orientation = None
orientation = Image.ROTATE_90
transposed_font = ImageFont.TransposedFont(font,
# get size of resulting text
box_size = draw.textsize(word)
# find possible places using integral image:
result = occupancy.sample_position(box_size[1] + self.margin,
box_size[0] + self.margin,
if result is not None or font_size == 0:
# if we didn't find a place, make font smaller
font_size -= self.font_step
if font_size < self.min_font_size:
# we were unable to draw any more
x, y = np.array(result) + self.margin // 2
# actually draw the text
draw.text((y, x), word, fill="white")
positions.append((x, y))
colors.append(self.color_func(word, font_size=font_size,
position=(x, y),
font_path=self.font_path, **kwargs))
# recompute integral image
if self.mask is None:
img_array = np.asarray(img_grey)
img_array = np.asarray(img_grey) + boolean_mask
# recompute bottom right
# the order of the cumsum's is important for speed ?!
occupancy.update(img_array, x, y)
self.layout_ = list(zip(frequencies, font_sizes, positions, orientations, colors))
return self
def process_text(self, text):
"""Splits a long text into words, eliminates the stopwords.
text : string
The text to be processed.
words : list of tuples (string, float)
Word tokens with associated frequency.
There are better ways to do word tokenization, but I don't want to
include all those things.
d = {}
flags = (re.UNICODE if sys.version < '3' and type(text) is unicode
else 0)
for word in re.findall(r"\w[\w']*", text, flags=flags):
if word.isdigit():
word_lower = word.lower()
if word_lower in self.stopwords:
# Look in lowercase dict.
if word_lower in d:
d2 = d[word_lower]
d2 = {}
d[word_lower] = d2
# Look in any case dict.
d2[word] = d2.get(word, 0) + 1
d3 = {}
for d2 in d.values():
# Get the most popular case.
first = max(d2.items(), key=item1)[0]
d3[first] = sum(d2.values())
# merge plurals into the singular count (simple cases only)
for key in list(d3.keys()):
if key.endswith('s'):
key_singular = key[:-1]
if key_singular in d3:
val_plural = d3[key]
val_singular = d3[key_singular]
d3[key_singular] = val_singular + val_plural
del d3[key]
words = sorted(d3.items(), key=item1, reverse=True)
words = words[:self.max_words]
maximum = float(max(d3.values()))
for i, (word, count) in enumerate(words):
words[i] = word, count / maximum
self.words_ = words
return words
def generate_from_text(self, text):
"""Generate wordcloud from text.
Calls process_text and fit_words.
return self
def generate(self, text):
"""Generate wordcloud from text.
Alias to generate_from_text.
Calls process_text and fit_words.
return self.generate_from_text(text)
def _check_generated(self):
"""Check if ``layout_`` was computed, otherwise raise error."""
if not hasattr(self, "layout_"):
raise ValueError("WordCloud has not been calculated, call generate first.")
def to_image(self):
if self.mask is not None:
width = self.mask.shape[1]
height = self.mask.shape[0]
height, width = self.height, self.width
img =, (width * self.scale, height * self.scale),
draw = ImageDraw.Draw(img)
for (word, count), font_size, position, orientation, color in self.layout_:
font = ImageFont.truetype(self.font_path, font_size * self.scale)
transposed_font = ImageFont.TransposedFont(font,
pos = (position[1] * self.scale, position[0] * self.scale)
draw.text(pos, word, fill=color)
return img
def recolor(self, random_state=None, color_func=None):
"""Recolor existing layout.
Applying a new coloring is much faster than generating the whole wordcloud.
random_state : RandomState, int, or None, default=None
If not None, a fixed random state is used. If an int is given, this
is used as seed for a random.Random state.
color_func : function or None, default=None
Function to generate new color from word count, font size, position
and orientation. If None, self.color_func is used.
if isinstance(random_state, int):
random_state = Random(random_state)
kwargs = self.kwargs
if color_func is None:
color_func = self.color_func
self.layout_ = [(word_freq, font_size, position, orientation,
color_func(word=word_freq[0], font_size=font_size,
position=position, orientation=orientation,
random_state=random_state, font_path=self.font_path, ordinal=i, **kwargs))
for i, (word_freq, font_size, position, orientation, _) in enumerate(self.layout_)]
return self
def to_file(self, filename):
"""Export to image file.
filename : string
Location to write to.
img = self.to_image()
return self
def to_array(self):
"""Convert to numpy array.
image : nd-array size (width, height, 3)
Word cloud image as numpy matrix.
return np.array(self.to_image())
def __array__(self):
"""Convert to numpy array.
image : nd-array size (width, height, 3)
Word cloud image as numpy matrix.
return self.to_array()
def to_html(self):
raise NotImplementedError("FIXME!!!")