Hi all,
It’s been a while since I posted a new article. This is because I have ventured into the exciting field of Machine Learning and have been doing some competitions on Kaggle.
In this quick post I just wanted to share some Python code which can be used to benchmark, test, and develop Machine Learning algorithms with any size of data.
In other words: this dataset generation can be used to do emperical measurements of Machine Learning algorithms.
The code has been commented and I will include a Theano version and a numpy-only version of the code.
Numpy dataset generator
def load_testing(size=5, length=10000, classes=3):
# Super-duper important: set a seed so you always have the same data over multiple runs.
np.random.seed(123)
# Generate random data between 0 and 1 as a numpy array.
# The size determines the amount of input values.
x=[]
for i in range (0, length):
x.append(np.asarray(np.random.uniform(low=0, high=1, size=size), dtype='float64'))
# Split up the input array into training/test/validation sets.
train_set_x = x[:int(len(x)*0.6)]
test_set_x = x[int(len(x)*0.6):int(len(x)*0.8)]
valid_set_x = x[int(len(x)*0.8):]
# For each input in x, we will generate a class for y.
# If classes is set to less than or equal to 1, it will output real numbers
# for regression.
y=[]
for row in x:
row_tmp = list()
for i in range(0, len(row)):
row_tmp.append(row[i] * 2. - 1)
row_tmp[i] = (np.tanh(row_tmp[i])) * (i+1)
output = np.sin(np.mean(row_tmp))
# If classes > 1 we will output classes, else we output real numbers.
if (classes > 1):
classnum = 0
# Generate class limits depending on the amount of classes you want.
classranges = np.arange(-1,1,(2./float(classes)))[::-1]
for i in classranges:
if (output >= i):
y.append(classnum)
break
classnum = classnum + 1
else:
y.append(output)
# Convert Y to a numpy array and split it up into train/test/validation sets.
y = np.asarray(y)
train_set_y = y[:int(len(x)*0.6)]
test_set_y = y[int(len(x)*0.6):int(len(x)*0.8)]
valid_set_y = y[int(len(x)*0.8):]
# Return the dataset in pairs of x,y for train/test/validation sets.
rval = [(train_set_x, train_set_y), (valid_set_x, valid_set_y),
(test_set_x, test_set_y)]
return rval
Theano dataset generator
import numpy as np
import theano
import theano.tensor as T
def load_testing(size=5, length=10000, classes=3):
# Super-duper important: set a seed so you always have the same data over multiple runs.
np.random.seed(123)
# Generate random data between 0 and 1 as a numpy array.
# The size determines the amount of input values.
x=[]
for i in range (0, length):
x.append(np.asarray(np.random.uniform(low=0, high=1, size=size), dtype='float64'))
# Split up the input array into training/test/validation sets.
train_set_x = x[:int(len(x)*0.6)]
test_set_x = x[int(len(x)*0.6):int(len(x)*0.8)]
valid_set_x = x[int(len(x)*0.8):]
# For each input in x, we will generate a class for y.
# If classes is set to less than or equal to 1, it will output real numbers
# for regression.
y=[]
for row in x:
row_tmp = list()
for i in range(0, len(row)):
# Normalize from -1 to 1 and take the hyperbolic tangent of the separate values.
# Note: we do "* (i+1)" on each value to give a different importance to the input variables.
row_tmp.append(row[i] * 2. - 1)
row_tmp[i] = (np.tanh(row_tmp[i])) * (i+1)
output = np.sin(np.mean(row_tmp))
# If classes > 1 we will output classes, else we output real numbers.
if (classes > 1):
classnum = 0
# Generate class limits depending on the amount of classes you want.
classranges = np.arange(-1,1,(2./float(classes)))[::-1]
for i in classranges:
if (output >= i):
y.append(classnum)
break
classnum = classnum + 1
else:
y.append(output)
# Convert Y to a numpy array and split it up into train/test/validation sets.
y = np.asarray(y)
train_set_y = y[:int(len(x)*0.6)]
test_set_y = y[int(len(x)*0.6):int(len(x)*0.8)]
valid_set_y = y[int(len(x)*0.8):]
def shared_dataset(data_xy, borrow=True):
#Create a shared dataset. This is only if you are using Theano
data_x, data_y = data_xy
shared_x = theano.shared(np.asarray(data_x,
dtype=theano.config.floatX),
borrow=borrow)
shared_y = theano.shared(np.asarray(data_y,
dtype=theano.config.floatX),
borrow=borrow)
return shared_x, T.cast(shared_y, 'int32')
if (use_theano):
# Convert the numpy arrays into theano datasets, IF using theano.
train_set_x, train_set_y = shared_dataset((train_set_x, train_set_y))
test_set_x, test_set_y = shared_dataset((test_set_x, test_set_y))
valid_set_x, valid_set_y = shared_dataset((valid_set_x, valid_set_y))
# Return the dataset in pairs of x,y for train/test/validation sets.
rval = [(train_set_x, train_set_y), (valid_set_x, valid_set_y),
(test_set_x, test_set_y)]
return rvalHave fun with these snippets!
Share the knowledge!
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