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1500 questions
8
votes
2 answers
Forecasting Multiple (few hundreds) uni-variate time series with inflated zeros
I am a novice seeking help to gain experience in Data Science.
Let us take a scenario where a big company would like to forecast its sales (a specific product) across different stores in different geographic locations.
As an Analyst, a task is given…
wlaura
- 81
- 3
8
votes
2 answers
What is the input size of Alex net
In the paper ImageNet Classification with Deep Convolutional Neural Networks, the size of input image is 224x224. The following figure shows the input size.
From caffe, deploy.prototxt file from the directory of the bvlc_alexnet says that the input…
Jogging Song
- 183
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8
votes
9 answers
Confusion Matrix - Get Items FP/FN/TP/TN - Python
After run my python code:
print(confusion_matrix(x_test, x_pred))
I get this:
[100 32
211 21]
My question is how can I get the following list:
True positive = 100
False positive = 32
False negative = 211
True negative = 21
Is this possible?
John_Rodgers
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8
votes
2 answers
LSTM: How to deal with nonstationarity when predicting a time series
I want to do one-step-ahead predictions for time series with LSTM.
To understand the algorithm, I built myself a toy example: A simple autocorrelated process.
def my_process(n, p, drift=0, displacement=0):
x = np.zeros(n)
for i in range(1,…
Elias Strehle
- 1,636
- 9
- 25
8
votes
2 answers
How to plot cost versus number of iterations in scikit learn?
One of the recommendations in the Coursera Machine Learning course when working with gradient descent based algorithms is:
Debugging gradient descent. Make a plot with number of iterations on the x-axis. Now plot the cost function, J(θ) over the…
Chris Snow
- 215
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8
votes
1 answer
how to compare different sets of time series data
I am trying to do some anomaly detection between time#series using Python and sklearn (but other package suggestions are definitely welcome!).
I have a set of 10 time-series; each time-series consists of data collected from torque value of a tire…
alwaysaskingquestions
- 191
- 1
- 4
8
votes
3 answers
Feature selection for tracking user activity within an application
I am developing a system that is intended to capture the "context" of user activity within an application; it is a framework that web applications can use to tag user activity based on requests made to the system. It is hoped that this data can…
Joshua Barron
- 181
- 3
8
votes
2 answers
Applying dimensionality reduction on OneHotEncoded array
I have a really large data set with mixed variables. I have converted categorical variables to numerical using OneHotEncoding and it has resulted in more than a couple of thousand different features, combined that is.
Is it possible to apply…
moirK
- 231
- 2
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8
votes
1 answer
How to download dynamic files created during work on Google Colab?
I have two different files and on the first, I tried to save data to file as:
np.save(open(Q1_TRAINING_DATA_FILE, 'wb'), q1_data)
On second file, i'm trying to load it the same way using:
q1_data = np.load(open(Q1_TRAINING_DATA_FILE, 'rb'))
I then…
vikbehal
- 185
- 1
- 1
- 7
8
votes
2 answers
Difference between explicit and implicit density with and without the relation to neural network
I have a lack of understanding about this issue. Could anybody explain it or give an advice to a good literature regarding it? I don't understand what is a explicit density model and how it differs from an implicit density one. Could anyone…
malocho
- 183
- 1
- 6
8
votes
0 answers
Python : Feature Matching + Homography to find Multiple Objects
I'm trying to use OpenCV via Python to find multiple objects in a train image and match it with the key points detected from a query image. For my case, I'm trying to detect the tennis courts in the image provided below. I looked at the online…
Reward
- 81
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8
votes
4 answers
Faster-RCNN how anchor work with slider in RPN layer?
I am trying to understand the whole Faster-RCNN,
From https://www.quora.com/How-does-the-region-proposal-network-RPN-in-Faster-R-CNN-work
Then a sliding window is run spatially on these feature maps. The size of sliding window is n×n (here 3×3).…
Mithril
- 373
- 6
- 15
8
votes
3 answers
Should there be a flat layer in between the conv layers and dense layer in YOLO?
Should there be a flat layer in between the conv layers and dense layer in YOLO?
It's something not specified in the paper, but I see most implementations of YOLO on github do this. In my implementation, I do not flatten the 7*7*1024 feature map and…
Gaurav Kumar
- 324
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- 7
8
votes
1 answer
Document classification: tf-idf prior to or after feature filtering?
I have a document classification project where I am getting site content and then assigning one of numerous labels to the website according to content.
I found out that tf-idf could be very useful for this. However, I was unsure as to when exactly…
user991710
- 71
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8
votes
2 answers
Does it make sense to combine PCA with an artificial neural network?
I have a Dataset of around 200 features. Most of them are categorical and only a few are numerical. It seems that an artificial neural network with an Autoencoder has some problems with that kind and amount of features. Therefore, I thought to use…
Rene B.
- 369
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- 7
- 13