input code:
data = pd.read_csv('test.csv')
data.head()
data['Density'] = data['Flow [Veh/h]'] / data['Speed [km/h]']
data = data.replace(np.nan, 1)
X = data['Density']
y = data['Speed [km/h]']
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.4, random_state=101)
from sklearn.linear_model import LinearRegression
lm = LinearRegression()
lm.fit(X_train,y_train) #HERE I GOT AN ERROR
Reshape your data either using array.reshape(-1, 1) if your data has a single feature or array.reshape(1, -1) if it contains a single sample.
You can try changing your variable X as the following:
X = data['Density'].values.reshape((-1, 1))
I had faced the same error, where my feature set had only one variable. The above change solved the issue for me.
Try using [[]] while taking the parameters:
X = data[['Density']]
Related
I am trying to do a simple linear regression model to estimate the sales price of an item for borrowers we don't have contract information on. I'm using data from borrowers we do have price and payment info on and using sklearn's LinearRegression model but getting an error when I call the predict() method on the model. The exact error:
ValueError: X has 844 features, but LinearRegression is expecting 2529 features as input.
Here is my code, I feel like it's fairly straightforward. The build_customer_df is a method call that returns the dataframe with some column formatting, nothing fancy:
`
fp = Path('master_borrower.xlsx')
df = build_customer_df(fp)
df = df[['payment', 'trailer_sales_price']]
df = df[df['payment']!= 0]
X = df['payment'].values
y = df['trailer_sales_price'].values
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.25, random_state=1)
X_test = X_test.reshape(1,-1)
X_train = X_train.reshape(1,-1)
y_train = y_train.reshape(1,-1)
y_test = y_test.reshape(1,-1)
model = linear_model.LinearRegression()
model.fit(X_train, y_train)
predictions = model.predict(X_test)
I would like to use a RobustScaler for preprocessing data. In sklearn it can be found in
sklearn.preprocessing.RobustScaler
. However, I am using pyspark, so I tried to import it with:
from pyspark.ml.feature import RobustScaler
However, I receive the following error:
ImportError: cannot import name 'RobustScaler' from 'pyspark.ml.feature'
As pault pointed out, RobustScaler is implemented only in pyspark 3. I am trying to implement it as:
class PySpark_RobustScaler(Pipeline):
def __init__(self):
pass
def fit(self, df):
return self
def transform(self, df):
self._df = df
for col_name in self._df.columns:
q1, q2, q3 = self._df.approxQuantile(col_name, [0.25, 0.5, 0.75], 0.00)
self._df = self._df.withColumn(col_name, 2.0*(sf.col(col_name)-q2)/(q3-q1))
return self._df
arr = np.array(
[[ 1., -2., 2.],
[ -2., 1., 3.],
[ 4., 1., -2.]]
)
rdd1 = sc.parallelize(arr)
rdd2 = rdd1.map(lambda x: [int(i) for i in x])
df_sprk = rdd2.toDF(["A", "B", "C"])
df_pd = pd.DataFrame(arr, columns=list('ABC'))
PySpark_RobustScaler().fit(df_sprk).transform(df_sprk).show()
print(RobustScaler().fit(df_pd).transform(df_pd))
However I have found that to obtain the same result of sklearn I have to multiply the result by 2. Furthermore, I am worried that if a column has many values close to zero, the interquartile range q3-q1 could become too small and let the result diverge, creating null values.
Does anyone have any suggestions on how to improve it?
This feature has been released in recent pyspark versions.
I applied k-fold cross validation to split data into train and test sets.
But when I want to get train and test sets I have these errors:
AttributeError: 'numpy.ndarray' object has no attribute 'iloc'
Thanks for your help.
y = df_dummies['Churn'].values
X = df_dummies.drop(columns = ['Churn'])
from sklearn.preprocessing import MinMaxScaler
features = X.columns.values
scaler = MinMaxScaler(feature_range = (0,1))
scaler.fit(X)
X = pd.DataFrame(scaler.transform(X))
X.columns = features
from sklearn.model_selection import KFold
kf=KFold(n_splits=5,shuffle=True)
for train,test in kf.split(X):
print("%s %s" % (train,test))
for train_index, test_index in kf.split(X):
print("TRAIN:", train_index, "TEST:", test_index)
X_train, X_test = X.iloc[train_index], X.iloc[test_index]
y_train, y_test = y.iloc[train_index], y.iloc[test_index]
from sklearn.linear_model import LogisticRegression
CLF = LogisticRegression().fit(X_train, y_train)
print('Accuracy of Logistic regression classifier on training set: {:.2f}'
.format(CLF.score(X_train, y_train)))
print('Accuracy of Logistic regression classifier on test set: {:.2f}'
.format(CLF.score(X_test, y_test)))
NameError: name 'y_train' is not defined
The issue is that df_dummies['Churn'].values returns an array not a dataframe. But you are trying to get attributes from an array which don't exist. The iloc function is in pandas.DataFrame.
Use y = df_dummies['Churn'] instead.
Reference: https://pandas.pydata.org/pandas-docs/version/0.23.4/generated/pandas.DataFrame.iloc.html#pandas.DataFrame.iloc
PS: I don't know how these type of questions could be migrated to a sister site. Perhaps, someone who knows that could migrate this to cross-validated please.
I am trying to load my own dataset and I use a custom Dataloader that reads in images and labels and converts them to PyTorch Tensors. However when the Dataloader is instantiated it returns strings x "image" and y "labels" but not the real values or tensors when read (iter)
print(self.train_loader) # shows a Tensor object
tic = time.time()
with tqdm(total=self.num_train) as pbar:
for i, (x, y) in enumerate(self.train_loader): # x and y are returned as string (where it fails)
if self.use_gpu:
x, y = x.cuda(), y.cuda()
x, y = Variable(x), Variable(y)
This is how dataloader.py looks like:
from __future__ import print_function, division #ds
import numpy as np
from utils import plot_images
import os #ds
import pandas as pd #ds
from skimage import io, transform #ds
import torch
from torchvision import datasets
from torch.utils.data import Dataset, DataLoader #ds
from torchvision import transforms
from torchvision import utils #ds
from torch.utils.data.sampler import SubsetRandomSampler
class CDataset(Dataset):
def __init__(self, csv_file, root_dir, transform=None):
"""
Args:
csv_file (string): Path to the csv file with annotations.
root_dir (string): Directory with all the images.
transform (callable, optional): Optional transform to be applied
on a sample.
"""
self.frame = pd.read_csv(csv_file)
self.root_dir = root_dir
self.transform = transform
def __len__(self):
return len(self.frame)
def __getitem__(self, idx):
img_name = os.path.join(self.root_dir,
self.frame.iloc[idx, 0]+'.jpg')
image = io.imread(img_name)
# image = image.transpose((2, 0, 1))
labels = np.array(self.frame.iloc[idx, 1])#.as_matrix() #ds
#landmarks = landmarks.astype('float').reshape(-1, 2)
#print(image.shape)
#print(img_name,labels)
sample = {'image': image, 'labels': labels}
if self.transform:
sample = self.transform(sample)
return sample
class ToTensor(object):
"""Convert ndarrays in sample to Tensors."""
def __call__(self, sample):
image, labels = sample['image'], sample['labels']
#print(image)
#print(labels)
# swap color axis because
# numpy image: H x W x C
# torch image: C X H X W
image = image.transpose((2, 0, 1))
#print(image.shape)
#print((torch.from_numpy(image)))
#print((torch.from_numpy(labels)))
return {'image': torch.from_numpy(image),
'labels': torch.from_numpy(labels)}
def get_train_valid_loader(data_dir,
batch_size,
random_seed,
#valid_size=0.1, #ds
#shuffle=True,
show_sample=False,
num_workers=4,
pin_memory=False):
"""
Utility function for loading and returning train and valid
multi-process iterators over the MNIST dataset. A sample
9x9 grid of the images can be optionally displayed.
If using CUDA, num_workers should be set to 1 and pin_memory to True.
Args
----
- data_dir: path directory to the dataset.
- batch_size: how many samples per batch to load.
- random_seed: fix seed for reproducibility.
- #ds valid_size: percentage split of the training set used for
the validation set. Should be a float in the range [0, 1].
In the paper, this number is set to 0.1.
- shuffle: whether to shuffle the train/validation indices.
- show_sample: plot 9x9 sample grid of the dataset.
- num_workers: number of subprocesses to use when loading the dataset.
- pin_memory: whether to copy tensors into CUDA pinned memory. Set it to
True if using GPU.
Returns
-------
- train_loader: training set iterator.
- valid_loader: validation set iterator.
"""
#ds
#error_msg = "[!] valid_size should be in the range [0, 1]."
#assert ((valid_size >= 0) and (valid_size <= 1)), error_msg
#ds
# define transforms
#normalize = transforms.Normalize((0.1307,), (0.3081,))
trans = transforms.Compose([
ToTensor(), #normalize,
])
# load train dataset
#train_dataset = datasets.MNIST(
# data_dir, train=True, download=True, transform=trans
#)
train_dataset = CDataset(csv_file='/home/Desktop/6June17/util/train.csv',
root_dir='/home/caffe/data/images/',transform=trans)
# load validation dataset
#valid_dataset = datasets.MNIST( #ds
# data_dir, train=True, download=True, transform=trans #ds
#)
valid_dataset = CDataset(csv_file='/home/Desktop/6June17/util/eval.csv',
root_dir='/home/caffe/data/images/',transform=trans)
num_train = len(train_dataset)
train_indices = list(range(num_train))
#ds split = int(np.floor(valid_size * num_train))
num_valid = len(valid_dataset) #ds
valid_indices = list(range(num_valid)) #ds
#if shuffle:
# np.random.seed(random_seed)
# np.random.shuffle(indices)
#ds train_idx, valid_idx = indices[split:], indices[:split]
train_idx = train_indices #ds
valid_idx = valid_indices #ds
train_sampler = SubsetRandomSampler(train_idx)
valid_sampler = SubsetRandomSampler(valid_idx)
train_loader = torch.utils.data.DataLoader(
train_dataset, batch_size=batch_size, sampler=train_sampler,
num_workers=num_workers, pin_memory=pin_memory,
)
print(train_loader)
valid_loader = torch.utils.data.DataLoader(
valid_dataset, batch_size=batch_size, sampler=valid_sampler,
num_workers=num_workers, pin_memory=pin_memory,
)
# visualize some images
if show_sample:
sample_loader = torch.utils.data.DataLoader(
dataset, batch_size=9, #shuffle=shuffle,
num_workers=num_workers, pin_memory=pin_memory
)
data_iter = iter(sample_loader)
images, labels = data_iter.next()
X = images.numpy()
X = np.transpose(X, [0, 2, 3, 1])
plot_images(X, labels)
return (train_loader, valid_loader)
def get_test_loader(data_dir,
batch_size,
num_workers=4,
pin_memory=False):
"""
Utility function for loading and returning a multi-process
test iterator over the MNIST dataset.
If using CUDA, num_workers should be set to 1 and pin_memory to True.
Args
----
- data_dir: path directory to the dataset.
- batch_size: how many samples per batch to load.
- num_workers: number of subprocesses to use when loading the dataset.
- pin_memory: whether to copy tensors into CUDA pinned memory. Set it to
True if using GPU.
Returns
-------
- data_loader: test set iterator.
"""
# define transforms
#normalize = transforms.Normalize((0.1307,), (0.3081,))
trans = transforms.Compose([
ToTensor(), #normalize,
])
# load dataset
#dataset = datasets.MNIST(
# data_dir, train=False, download=True, transform=trans
#)
test_dataset = CDataset(csv_file='/home/Desktop/6June17/util/test.csv',
root_dir='/home/caffe/data/images/',transform=trans)
test_loader = torch.utils.data.DataLoader(
test_dataset, batch_size=batch_size, shuffle=False,
num_workers=num_workers, pin_memory=pin_memory,
)
return test_loader
#for i_batch, sample_batched in enumerate(dataloader):
# print(i_batch, sample_batched['image'].size(),
# sample_batched['landmarks'].size())
# # observe 4th batch and stop.
# if i_batch == 3:
# plt.figure()
# show_landmarks_batch(sample_batched)
# plt.axis('off')
# plt.ioff()
# plt.show()
# break
A minimal working sample will be difficult to post here but basically I am trying to modify this project http://torch.ch/blog/2015/09/21/rmva.html which works smoothly with MNIST. I am just trying to run it with my own dataset with the custom dataloader.py I use above.
It instantiates a Dataloader like this:
in trainer.py:
if config.is_train:
self.train_loader = data_loader[0]
self.valid_loader = data_loader[1]
self.num_train = len(self.train_loader.sampler.indices)
self.num_valid = len(self.valid_loader.sampler.indices)
-> run from main.py:
if config.is_train:
data_loader = get_train_valid_loader(
config.data_dir, config.batch_size,
config.random_seed, #config.valid_size,
#config.shuffle,
config.show_sample, **kwargs
)
You are not properly using python's enumerate(). (x, y) are currently assigned the 2 keys of your batch dictionary i.e. the strings "image" and "labels". This should solve your problem:
for i, batch in enumerate(self.train_loader):
x, y = batch["image"], batch["labels"]
# ...
After some research, I was able to predict the future value using the LSTM code below. I have also attached the Dmd1ahr.csv file in the github link that I am using.
https://github.com/ukeshchawal/hello-world/blob/master/Dmd1ahr.csv
As you all can see below, 90 data points are training sets and 91st to 100th are future value prediction.
However some of the questions that I still have are:
In order to predict these values I had to originally take more than hundred data sets (here, I have taken 500 data sets) which is not exactly what my primary goal is. Is there a way that given 500 data sets, it will predict the rest 10 or 20 out of sample data points? If yes, will you please write me a sample code where you can just take 500 data points from Dmd1ahr.csv file attached below and it will predict some future values (say 501 to 520) based on those 500 points?
The prediction are way off compared to the one who have in your blogs (definitely indicates for parameter tuning - I tried changing epochs, LSTM layers, Activation, optimizer). What other parameter tuning I can do to make it more robust?
Thank you'll in advance.
import numpy as np
import matplotlib.pyplot as plt
import pandas
# By twaking the architecture it could be made more robust
np.random.seed(7)
numOfSamples = 500
lengthTrain = 90
lengthValidation = 100
look_back = 1 # Can be set higher, in my experiments it made performance worse though
transientTime = 90 # Time to "burn in" time series
series = pandas.read_csv('Dmd1ahr.csv')
def generateTrainData(series, i, look_back):
return series[i:look_back+i+1]
trainX = np.stack([generateTrainData(series, i, look_back) for i in range(lengthTrain)])
testX = np.stack([generateTrainData(series, lengthTrain + i, look_back) for i in range(lengthValidation)])
trainX = trainX.reshape((lengthTrain,look_back+1,1))
testX = testX.reshape((lengthValidation, look_back + 1, 1))
trainY = trainX[:,1:,:]
trainX = trainX[:,:-1,:]
testY = testX[:,1:,:]
testX = testX[:,:-1,:]
############### Build Model ###############
import keras
from keras.models import Model
from keras import layers
from keras import regularizers
inputs = layers.Input(batch_shape=(1,look_back,1), name="main_input")
inputsAux = layers.Input(batch_shape=(1,look_back,1), name="aux_input")
# this layer makes the actual prediction, i.e. decides if and how much it goes up or down
x = layers.recurrent.LSTM(300,return_sequences=True, stateful=True)(inputs)
x = layers.recurrent.LSTM(200,return_sequences=True, stateful=True)(inputs)
x = layers.recurrent.LSTM(100,return_sequences=True, stateful=True)(inputs)
x = layers.recurrent.LSTM(50,return_sequences=True, stateful=True)(inputs)
x = layers.wrappers.TimeDistributed(layers.Dense(1, activation="linear",
kernel_regularizer=regularizers.l2(0.005),
activity_regularizer=regularizers.l1(0.005)))(x)
# auxillary input, the current input will be feed directly to the output
# this way the prediction from the step before will be used as a "base", and the Network just have to
# learn if it goes a little up or down
auxX = layers.wrappers.TimeDistributed(layers.Dense(1,
kernel_initializer=keras.initializers.Constant(value=1),
bias_initializer='zeros',
input_shape=(1,1), activation="linear", trainable=False
))(inputsAux)
outputs = layers.add([x, auxX], name="main_output")
model = Model(inputs=[inputs, inputsAux], outputs=outputs)
model.compile(optimizer='adam',
loss='mean_squared_error',
metrics=['mean_squared_error'])
#model.summary()
#model.fit({"main_input": trainX, "aux_input": trainX[look_back-1,look_back,:]},{"main_output": trainY}, epochs=4, batch_size=1, shuffle=False)
model.fit({"main_input": trainX, "aux_input": trainX[:,look_back-1,:].reshape(lengthTrain,1,1)},{"main_output": trainY}, epochs=100, batch_size=1, shuffle=False)
############### make predictions ###############
burnedInPredictions = np.zeros(transientTime)
testPredictions = np.zeros(len(testX))
# burn series in, here use first transitionTime number of samples from test data
for i in range(transientTime):
prediction = model.predict([np.array(testX[i, :, 0].reshape(1, look_back, 1)), np.array(testX[i, look_back - 1, 0].reshape(1, 1, 1))])
testPredictions[i] = prediction[0,0,0]
burnedInPredictions[:] = testPredictions[:transientTime]
# prediction, now dont use any previous data whatsoever anymore, network just has to run on its own output
for i in range(transientTime, len(testX)):
prediction = model.predict([prediction, prediction])
testPredictions[i] = prediction[0,0,0]
# for plotting reasons
testPredictions[:np.size(burnedInPredictions)-1] = np.nan
############### plot results ###############
#import matplotlib.pyplot as plt
plt.plot(testX[:, 0, 0])
plt.show()
plt.plot(burnedInPredictions, label = "training")
plt.plot(testPredictions, label = "prediction")
plt.legend()
plt.show()