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H: Identifying repeating sequences of data in byte array
Given a sample of hexadecimal data, I would like to identify UNKNOWN sequences of bytes that are repeated throughout the sample. (Not searching for a known string or value) I am attempting to reverse engineer a network protocol, and I am working on determining d... |
H: How to replace levels with certain value?
I have a categorical variable in my dataset. I want to replace the levels which are present in test dataset and not present in training set with a value called "others"
Here is how it looks:
levels(training$var1) has levels as "1" "2" "3" "Others"
levels(testing$v... |
H: How to avoid overfitting in random forest?
I want to avoid overfitting in random forest. In this regard, I intend to use mtry, nodesize, and maxnodes etc. Could you please help me choose values for these parameters? I am using R.
Also, if possible, please tell me how I can use k-fold cross validation for random fo... |
H: Adjusting Probabilities When Using Alternative Cutoffs For Classification
I am reading Applied Predictive Modeling by Max Khun. I chapter 16 he discusses using alternate cutoffs as a remedy for class imbalance.
Suppose our model predicts the most likely outcome of 2 events, e1 and e2. We have e1 occurring with a pr... |
H: Machine learning for state-based transforms?
If I provide:
A list of possible transforms, and,
A list of input states, and,
A corresponding list of output states for each input state, and,
A fitness function to score each output state
Which subset of machine learning can direct me towards an optimization algorith... |
H: Deriving Confidences from Distribution of Class Probabilities for a Prediction
I run into this problem from time to time and have always felt like there should be an obvious answer.
I have probabilities for potential classes (from some classifier). I will offer the prediction of the class with the highest probabil... |
H: What features from sound waves to use for an AI song composer?
I am planning on making an AI song composer that would take in a bunch of songs of one instrument, extract musical notes (like ABCDEFG) and certain features from the sound wave, preform machine learning (most likely through recurrent neural networks), a... |
H: How to calculate most frequent value combinations
I have the following CSV data:
shot_id,round_id,hole,shotType,clubType,desiredShape,lineDirection,shotQuality,note
48,2,1,tee,driver,straight,straight,good,
49,2,1,approach,iron,straight,right,bad,
50,2,1,approach,wedge,straight,straight,bad,
51,2,1,approach,wedge,s... |
H: Markov Chains: How much steps to conclude a Transition Matrix
I have just learned Markov Chains which I am using to model a real world problem. The model comprises 3 states [a b c]. For now I am collection data and calculating transitional probabilities:-
T[a][b] = #transitions from a to b / #total transitions to a... |
H: How to extract a column that has the highest value within row in Hive?
I have a table, more or less in the following format
col1 col2 col3 ... col100
val1 val2 val3 ... val100
Where val* are doubles. Is there a way to extract for each row in which column is the highest value within row in Hive?
For example, for ta... |
H: Are there any interesting application of linear regression
Linear regression is a widely used ML algorithm. So far I have only encountered 'boring' applications of it. (e.g predict sales for next quarter, predict housing prices for next year , predict population of a country by 2020 etc.)
What are some interesting/... |
H: Shall I use the Euclidean Distance or the Cosine Similarity to compute the semantic similarity of two words?
I want to compute the semantic similarity of two words using their vector representations (obtained using e.g. word2vec, GloVe, etc.). Shall I use the Euclidean Distance or the Cosine Similarity?
The GloVe w... |
H: Combining Datasets with Different Features
I have multiple datasets, with slightly differing features. What tools can I use to make this a homogeneous dataset?
Dataset1:
featureA,featureB,featureC
1,7,3
4,8,4
Dataset2:
featureA,featureC,featureD,featureE
3,4,5,6
9,8,4,6
Homogeneous Dataset
featureA,featureB,featu... |
H: Newton-Raphson or EM Algorithm in Python
Is there any implementation of Newton-Raphson or EM Algorithm? Can I get the source code of it?
I tried googling, but didn't come across any. So asking here.
Thanks!
AI: scikit learn has the EM algorithm here.
Source code is available.
And if you are an R fan the mclust pack... |
H: Normalized Euclidean Distance versus cross correlation?
Normalized Euclidean Distance and Normalized Cross - Correlation can both be used as a metric of distance between vectors.
What is the difference between these metrics? It seems to me that they are the same, although I have not seen this explicitly stated i... |
H: Non-parametric approach to healthcare dataset?
I have a Healthcare dataset. I have been told to look at non-parametric approach to solve certain questions related to the dataset. I am little bit confused about non-parametric approach.
Do they mean density plot based approach (such as looking at the histogram)?
I ... |
H: how to perform Step calcuations in R
I have a rate-step plan for consumption with which I'm trying to total up costs. I have a rate plant that looks like this:
First 20 Kwh is Free;
Second 5 Kwh is $.1
Next 100 Kwh is $.053
Next 875 Kwh is $.042
Over 1000Kwh is $.039
Can someone provide a worked example... |
H: What does the Ip mean in the Bayesian Ridge Regression formula?
From http://scikit-learn.org/stable/modules/linear_model.html#bayesian-ridge-regression, they gave the bayesian ridge distribution as this:
$p(w|\lambda) = \mathcal{N}(w|0,\lambda^{-1}{I_{p}})$
And there is a variable $I_p$ but it's unexplained what do... |
H: Identifying top predictors from a mix of categorical and ordinal data
I have a dataset with 261 predictors scraped from a larger set of survey questions. 224 have values which are in a range of scale (some 1-10, some 1-4, some simply binary, all using 0 where no value is given), and the rest are unordered categorie... |
H: Is our data "Big Data" (Startup)
I worked at a startup/medium sized company and I am concerned that we may be over-engineering one of our products.
In essence, we will be consuming real-time coordinates from vehicles and users and performing analytics and machine learning on this incoming data. This processing can ... |
H: What makes a graph algorithm a good candidate for concurrency?
GraphX is the Apache Spark library for handling graph data. I was able to find a list of 'graph-parallel' algorithms on these slides (see slide 23). However, I am curious what characteristics of these algorithms make them parallelizable.
AI: Two words: ... |
H: Alignment of square nonorientable images/data
Another post where I don't know enough terminology to describe things efficiently. For the comments, please suggest some tags and keywords I can add to this post to make it better.
Say I have a 2D data structure where 'orientation' doesn't matter. The examples I ran int... |
H: Extra output layer in a neural network (Decimal to binary)
I'm working through a question from the online book.
I can understand that if the additional output layer is of 5 output neurons, I could probably set bias at 0.5 and weight of 0.5 each for the previous layer. But the question now ask for a new layer of fou... |
H: Do I need to buy a NVIDIA graphic card to run deep learning algorithm?
I am new in deep learning. I am running a MacBook Pro yosemite (upgraded from Snowleopard). I don't have a CUDA-enabled card GPU, and running the code on the CPU is extremely slow. I heard that I can buy some instances on AWS, but it seems that ... |
H: Contributions of each feature in classification?
I have some features and I am using Weka to classify my instances.
For example I have:
Number of adj number of adverb number of punctuation
in my feature set. However, I would like to know the contribution of each feature in the feature set. So what metrics or ... |
H: Sequence of numbers as single feature
Is it possible to use a sequence of numbers as one feature?
For example, using libsvm data format:
<label> <index1>:<value1> <index2>:<value2>
+1 1:123.02 2:1.23 3:5.45,2.22,6.76
+1 1:120.12 2:2.23 3:4.98,2.55,4.45
-1 1:199.99 2:2.13 3:4.98,2.22,6.98
...
Is there any special ... |
H: How to keep a subsetted value for calculating mean
I am currently learning R and I have to solve an Issue were I have to extract values from a data set which are from a specific month and from this values I should calculate the mean Temp.
I did it like that:
data[data$X..Month.. == 6,]
mean(data$X..Temp.., na.r... |
H: When to stop calculating values of each cell in the grid in Reinforcement Learning(dynamic programming) applied on gridworld
Considering application of Reinforcement learning(dynamic programming method performing value iteration) on grid world, in each of the iteration, I go through each of the cell of the grid and... |
H: Confusion in Policy Iteration and Value iteration in Reinforcement learning in Dynamic Programming
What I understood for value iteration while coding is that we need to have a policy fixed. According to that policy the value function of each state will be calculated. Right?
But in policy iteration the policy will c... |
H: Is it necessary to standardize your data before clustering?
Is it necessary to standardize your data before cluster? In the example from scikit learn about DBSCAN, here they do this in the line:
X = StandardScaler().fit_transform(X)
But I do not understand why it is necessary. After all, clustering does not assu... |
H: Value Updation Dynamic Programming Reinforcement learning
Regarding Value Iteration of Dynamic Programming(reinforcement learning) in grid world, the value updation of each state is given by:
Now Suppose i am in say box (3,2). I can go to (4,2)(up) (3,3)(right) and (1,3)(left) and none of these are my final stat... |
H: How to preprocess different kinds of data (continuous, discrete, categorical) before Decision Tree learning
I want to use some Decision Tree learning, such as the Random Forest classifier.
I have data of different types: continuous, discrete and categorical. How do I have to preprocess data in order to have consist... |
H: fit model with sd square
If I want to fit a nonlinear regression model with some parameters like $\sigma^2$(where $\sigma$ is the standard deviation, which is positive), how can I guarantee that $\hat{\sigma}$ is positive?
I mean, if I use maximum likelihood(and the model only have square term of $\sigma$), how doe... |
H: Merging repeating data cells in csv
I have a CSV file with around 1 Million rows.
Let say its have details like
Name | Age | Salary
name 1 52 10000
name 2 55 10043
name 3 50 100054
name 2 55 10023
name 1 52 100322...
and soon .
but i need to merge... |
H: Do you have any real example of Data Science reports?
I recently found this use cases on Kaggle for Data Science and Data Analytics.
Data Science Use Cases
However, I am curious to find examples and case studies of real reports from other professionals in some of those use cases on the link. Including hypothesis, t... |
H: Advise on making predictions given collection of dimensions and corresponding probabilities
I am a CS graduate but am very new to data science. I could use some expert advise/insight on a problem I am trying to solve. I've been through the titanic tutorial on gaggle.com which I think was helpful but my problem is a... |
H: How to plot/visualize clusters in scikit-learn (sklearn)?
I have done some clustering and I would like to visualize the results.
Here is the function I have written to plot my clusters:
import sklearn
from sklearn.cluster import DBSCAN
from sklearn import metrics
from sklearn.preprocessing import StandardScaler
... |
H: How to convert vector values to fit k-means algorithm function?
I have a set of user objects that I want to group using a $k$-means function from their quiz answers. Each quiz question had predefined answers with letter values "a", "b", "c", "d". If a user answers the question #1 with letter "b", I put this answer ... |
H: Developing an Empirical Model for Non-Linear Data
I have collected Temp vs. Time data for a controlled environment. I performed three tests, with the thermocouple in the same location for all three tests. I now have three Temp. vs. Time curves for this location. The graphs are shown here:
I am looking to generate ... |
H: Estimating destination according to previous data
I need an advice. I can resume my problem like that :
I have some travels in a database, for example :
Person1 travelled from CityA to CityB on Date1
Person1 travelled from CityB to CityC on Date2
Person2 travelled from CityB to CityD on Date3
...
We can consider t... |
H: What's an efficient way to compare and group millions of store names?
I'm a total amateur as far as data science goes, and I'm trying to figure out a way to do some string comparison on a large dataset.
I've a Google BigQuery table storing merchant transactions, but the store names are all over the board. For ex... |
H: When to use Random Forest over SVM and vice versa?
When would one use Random Forest over SVM and vice versa?
I understand that cross-validation and model comparison is an important aspect of choosing a model, but here I would like to learn more about rules of thumb and heuristics of the two methods.
Can someone pl... |
H: Recommendations for storing time series data
As part of my thesis I've done some experiments that have resulted in a reasonable amount of time-series data (motion-capture + eye movements). I have a way of storing and organizing all of this data, but it's made me wonder whether there are best practices out there for... |
H: Logistic Regression in R models for 1 or 0?
According to this link, it says SAS models for 0,
To model 1s rather than 0s, we use the descending option. We do this because by default, proc logistic models 0s rather than 1s
What happens in case of R's glm function? Does it model for 1 or 0? Is there a way to chan... |
H: Data frame mutation in R
I have a data frame of the following format:
Symbol Date Time Profit
$BANKNIFTY 4/1/2010 9:55:00 -1.18%
<br>$BANKNIFTY 4/1/2010 12:30:00 -2.84%
$BANKNIFTY 4/1/2010 12:45:00 7.17%
<br>$BANKNIFTY 5/1/2010 11:40:00 -7.11%
ZEEL 26/6/2012 13:50:00 24.75%
ZEEL 27... |
H: Find the column(s) name where the value of the variable matches a regex
I am trying to filter a data frame where I need to search for a regular expression within the data frame.
dim(df)
[1] 10299 561
I wanted to know if there is a way, I could find the name(s) of the column(s) where a particular regex may be avai... |
H: For logistic regression, Predict.glm() outputs $p$ or $ln(p/1-p)$?
I'm performing a logistic regression in R.
I wanted to know if the function predict.glm outputs $p$ (probability of event occurring) or log odds i.e. $log(p/1-p)$?
AI: It returns the log odds. You can see that with this basic example,
# Create a per... |
H: How is H2O faster than R or SAS?
I am trying to understand the abstract details that explain how h2o is faster than R and SAS for data science computations.
AI: I have used R, SAS Base and H2O. First, I do not think that H2O seeks to be either R or SAS.
H2O provides data mining algorithms that are highly efficient... |
H: users' percentile similarity measure
Having n vectors of percentile ranks for a list of common users between group #1 and groups #2:n
e.g. vec1 = {0.25, 0.1, 0.8, 0.75, 0.5, 0.6}
vec2 = {0.35, 0.2, 0.6, 0.45, 0.2, 0.9}
The percentile ranks represent activity frequency within the group for instance, opening tim... |
H: Which type of machine learning to use
We are working with a complex application i.e. a physical measurement in a lab, that has approximately 230 different input parameters, many of which are ranges or multiple-value.
The application produces a single output, which is then verified in an external (physical) process.... |
H: Can Hadoop be beneficial when data is in database tables and not in a file system
I work for a bank. Most of our data is in the form of database tables. Would we benefit by implementing Hadoop? I am of the impression that Hadoop is more for a Distributed File System (unstructured data) as opposed to OLAP databases ... |
H: Can all statistical algorithms be parallelized using a Map Reduce framework
Is it correct to say that any statistical learning algorithm (linear/logistic regression, SVM, neural network, random forest) can be implemented inside a Map Reduce framework? Or are there restrictions?
I guess there may be some algorithms... |
H: Understanding dropout and gradient descent
I am looking at how to implement dropout on deep neural networks and found something counter intuitive. In the forward phase dropout mask activations with a random tensor of 1s and 0s to force net to learn the average of the weights. This help the net to generalize better.... |
H: TF-IDF not a strong measure in this senario?
I am dealing with a data where I have only two documents and there are some words which are present in both. Now Term Frequencies (tf) of these words are very high for respective single document than the other. For e.g.
Word1 is present in Documents D1 and D2, and
tf(Wo... |
H: Classification problem where one attribute is a vector
Hello I am a layman trying to analyze game data from League of Legends, specifically looking at predicting the win rate for a given champion given an item build.
Outline
A player can own up to 6 items at the end of a game. They could have purchased these items ... |
H: Any usable libs to build and visualise SOM in python?
I tried SOMpy, though it is very crude now and works only with oldest versions of matplotlib.
Is there any fancy lib that can build SOM based on array and visualize it in Python?
AI: You could have a try on this package.
There is a working example on this page.... |
H: How does Performance function classify predictions as positive or negative? Package:ROCR
I'm performing a logistic regression on my training data. I used the glm function to get the model m. Now using the below codes from this link, I calculated AUC
$test\$score<-predict(m,type = 'response',test)$
$pred <- predi... |
H: Newbie: What is the difference between hypothesis class and models?
I am new to machine learning and I am confused with the terminology. Thus far, I used to view a hypothesis class as different instance of hypothesis function... Example: If we are talking about linear classification then different lines characteriz... |
H: Identify given patterns in unstructured data like text files
I wasn't sure if I had to ask it here or in Stackoverflow, but since I am also seeking research papers/algorithms and not only code, I decided to do it here.
When I have a text, I can manually write a regex to find all the possible outputs from what I wan... |
H: StackOverflow Tags Predictor...Suggest an Machine Learning Approach please?
I am trying to predict tags for stackoverflow questions and I am not able to decide which Machine Learning algorithm will be a correct approach for this.
Input: As a dataset I have mined stackoverflow questions, I have tokenized the data se... |
H: Connection between Regularization and Gradient Descent
I would like to understand regularization/shrinkage in the light of MLE/Gradient Descent. I know both concepts but I do not know/understand whether both are used to determine coefficients of a linear model. If so, what are the steps followed?
To further elabor... |
H: Python script/GUI to generate positive/negative images for CascadeClassifier?
For the first time, I am playing around with a Cascade Classifier with the OpenCV package (also new to the latter). I realized that it would probably be faster to write my own GUI/script to generate the needed positive and negative images... |
H: Original Meaning of "Intelligence" in "Business Intelligence"
What does the term "Intelligence" originally stand for in "Business Intelligence" ? Does it mean as used in "Artificial Intelligence" or as used in "Intelligence Agency" ?
In other words, does "Business Intelligence" mean: "Acting smart & intelligently i... |
H: Simple implementation of Apriori algorithm in R
I am preparing a lecture on data mining algorithms in R and I want to demonstrate the famous Apriori algorithm in it.
My question
Could anybody point me to a simple implementation of this algorithm in R?
(I am not looking for a package, e.g. arules, but for comprehens... |
H: Online/incremental unsupervised dimensionality reduction for use with classification for event prediction
Consider the application:
We have a set of users and items.
Users can perform different action types (think browsing, clicking, upvoting etc.) on different items.
Users and items accumulate a "profile" for eac... |
H: Passing TFIDF Feature Vector to a SGDClassifier from sklearn
import numpy as np
from sklearn import linear_model
X = np.array([[-1, -1], [-2, -1], [1, 1], [2, 1]])
Y = np.array(['C++', 'C#', 'java','python'])
clf = linear_model.SGDClassifier()
clf.fit(X, Y)
print (clf.predict([[1.7, 0.7]]))
#python
I am trying to... |
H: Optimizing parameters for a closed (black-box) system
I am working on a problem that involves finding optimal parameter values for a black-box system. This system consists of 6 inputs and produces a single output. I can compare the returned values to observed values to determine whether the system is well calibrate... |
H: What are the applications of Solr in Big Data?
Why is solr used in Big Data?
What is it's purpose?
AI: Solr is a highly scalable, fault tolerant search server.
So, you can store files in the form of JSON, XML, CSV or binary over HTTP.
And you can query it via GET and receive JSON, XML, CSV and binary results. It a... |
H: Manage x-axis using ggplot()
Source: https://d396qusza40orc.cloudfront.net/exdata%2Fdata%2FNEI_data.zip
Here is my data prep.
NEI <- readRDS("summarySCC_PM25.rds")
Baltimore <- NEI[NEI$fips=="24510", ]
Baltimore$type <- as.factor(Baltimore$type)
Total_Emmisssions <- aggregate(Baltimore$Emissions,
... |
H: Solve a pair of coupled nonlinear equations within certain limits
This answer to this question works only for situations in which the desired solution to the coupled functions is not restricted to a certain range.
But what if, for example, we wanted a solution such that 0 < x < 10 and 0 < y < 10?
There are function... |
H: Classifying transactions as malicious
I have a big data set of fake transactions for a company. Each row contains the username, credit card number, time, device used, and amount of money in the transaction. I need to classify each transaction as either malicious or not malicious and I am lost for ideas on where to ... |
H: What commercial software should a data scientist purchase?
I am setting up a work computer and have free reign here. My typical go-to software packages are all freely available, such as Rstudio and Anaconda.
I have thought about investing in commercial BI software such as Tableau or Spotfire, but nobody else in th... |
H: Classifying text documents using linear/incremental topics
I'm attempting to classify text documents using a few different dimensions. I'm trying to create arbitrary topics to classify such as size and relevance, which are linear or gradual in nature. For example:
size: tiny, small, medium, large, huge.
relevance:... |
H: SKNN regression problem
I am trying to learn scikit-learn neuralnetwork and am coming up against the same problem in regression where no matter the dataset I getting a horizontal straight line for my fit.
here is an example using the Linear regression example from scikit-learn and then using the SKNN regressor , s... |
H: Clustering large number of strings based on tags
I have string representations of text written by users in the form of parts of speech tags like so:
$NNDN,OVDANPN,PNVRV,^^V,^^!$^OV
and
^,G,#,!,N,R,$
etc. They are separated into two classes (0 or 1).
I want to be able to cluster these such that I will be able to ... |
H: Is supervised machine learning by definition predictive?
I am trying to organize a cheat sheet of sorts for data science, and I am working with the basic distinction between description, inference, and prediction. As examples of the first I see unsupervised methods described, and for the last I see supervised metho... |
H: Error Analysis for misclassification of text documents
I am working on a text classification work. The purpose of this work is to classify whether a particular document belong to class A or Class B.
I used KNN algorithm and i am able to get some decent results. However I want to know two things.
Why a particular ... |
H: Identifying templates with parameters in text fragments
I have a data set with text fragments having a fixed structure that can contain parameters.
Examples are:
Temperature today is 20 centigrades
Temperature today is 28 centigrades
or
Her eyes are blue and hair black.
Her eyes are green and hair brown.
The ... |
H: How to create clusters of position data?
I am asking this question because the previous one wasn't very helpful and I asked about a different solution for the same problem.
The Problem
I have lateral positions, xcoord, of vehicles over time which were recorded as the distances from the right edge of the road. This ... |
H: How to start analysing and modelling data for an academic project, when not a statistician or data scientist
I have collected data for a PhD thesis, and need help understanding how to build a road map to do analytical and statistical analysis. The PhD is not itself in statistics or machine learning, but I would lik... |
H: Reference of SVM Using Spark
Can somebody please give me some reference on implementing SVM using PySpark.
AI: The documentation of Apache Spark's MLib library has a neat and clear reference to the implementation of linear SVM's in Python.
It supports two models: SVMWithSGD and SVMModel |
H: Creating validation data for model comparison
I am working on building a scoring algorithm for student data,
say the attributes are :
name, location, age, class, school_name, skill1, skill2, skill3
based on these data I need to create a student score.
I need to assign weight-ages for age, class, school_name skill... |
H: Multiple confusion matrix for multiple training instances. Which one to take?
I am using Matlab Neural Network toolbox for a classification problem. Now considering a single set of data, if the inbuilt neural network is trained and classified with same data multiple number of time, different accuracy and different... |
H: what is nn.index mean in KNN output
I am getting attr(, "nn.index") as part of my KNN output in R. What is meant by that and how is this value getting calculated?
knn.pred <- knn(tdm.stack.nl_train, tdm.stack.nl_Test, tdm.cand_train)
print(knn.pred)
> knn.pred
[1] Silent Silent Silent Silent ... |
H: PhD program in statistics
I am a first year PhD student in statistics. During this year I have analyzed the scopes of interest of my scientific advisor and found them unpromising. He is majored in mixtures with varying concentrations models for which I have not found any references to authoritative sources.
Now I w... |
H: replicability / reproducibility in topic modeling (LDA)
If I'm not wrong, topic modeling (LDA) is not replicable, i.e. it gives different results in different runs. Where does this come from (where does this randomness come from and why is it necessary?) and what can be done to solve this issue or gain more stabili... |
H: Beggining in machine learning
I just want to know which books, courses,videos, links,etc do you recommend me to start in machine learning, neural networks, languajes most commonly used. I want to start from zero, just in the begging of all beacuse I have not experience in this kind of algorithms but it's something ... |
H: Equipment failure prediction
I have a system that manages equipments. When these equipments are faulty, they will be serviced. Imagine my dataset looks like this:
ID
Type
# of times serviced
Example Data:
|ID| Type | #serviced |
|1 | iphone | 1 |
|2 | iphone | 0 |
|3 | android | 1 ... |
H: Which value of output should be taken in multiple sessions of training Neural Network
Suppose I am using Neural Network for a 2 class classification. After training the network with the training set, I want to predict the class label of a dataset with no class label. Now with retraining, the same dataset gives diff... |
H: Looking for a 'CITY, STATE' within a body of text (from a CITY-STATE database)
I'm looking for an optimal way to search a large body of text for a combination of words that resemble any CITY, STATE combination I have in a separate CITY-STATE database.
My only idea would be to do a separate search against the body o... |
H: What makes columnar databases suitable for data science?
What are some of the advantages of columnar data-stores which make them more suitable for data science and analytics?
AI: A column-oriented database (=columnar data-store) stores the data of a table column by column on the disk, while a row-oriented database ... |
H: How to binary encode multi-valued categorical variable from Pandas dataframe?
Suppose we have the following dataframe with multiple values for a certain column:
categories
0 - ["A", "B"]
1 - ["B", "C", "D"]
2 - ["B", "D"]
How can we get a table like this?
"A" "B" "C" "D"
0 - 1 1 0 0
1 - 0 1 ... |
H: Dividing data between test, learn and predict
I was posting on stats.stackexchange but perhaps I should be posting here.
Context. Subscription business that charges users a monthly fee for access to the service. Management would like to predict "churn" - subscriptions who are likely to cancel. Management would like... |
H: What is conjugate gradient descent?
What is Conjugate Gradient Descent of Neural Network? How is it different from Gradient Descent technique?
I came across a resource, but was unable to understand the difference between the two methods. It has mentioned in the procedure that:
the next search direction is determin... |
H: Is there a library that would perform segmented linear regression in python?
There is a package named segmented in R. Is there a similar package in python?
AI: No, currently there isn't a package in Python that does segmented linear regression as thoroughly as those in R (e.g. R packages listed in this blog post). ... |
H: Credit card fraud detection - anomaly detection based on amount of money to be withdrawn?
I am trying to figure out how the amount of money that a customer would want to withdraw on an ATM tell us if the transaction is fraudulent or not.There are other attributes, of course, but now I would want to hear your views ... |
H: Correctly interpreting Cosine Angular Distance Similarity & Euclidean Distance Similarity
As an example, let's say I have a very simple data set. I am given a csv with three columns, user_id, book_id, rating. The rating can be any number 0-5, where 0 means the user has NOT rated the book.
Let's say I randomly pick ... |
H: Filling missing data with other than mean values
What are all the options available for filling in missing data?
One obvious choice is the mean, but if the percentage of missing data is large, it will decrease the accuracy.
So how do we deal with missing values if they are are lot of them?
AI: There are of course o... |
H: Behaviour of Learning Algorithms on Random Data
Suppose we collect data for 100,000 tosses of a fair coin and record "Heads" or "Tails" as the value for the attribute outcome and also record the time, temprature and other irrelevant attributes.
We know that the outcome of each toss is random so there should be no w... |
H: Voting combined results from different classifiers gave bad accuracy
I used following classifiers along with their accuracies:
Random forest - 85 %
SVM - 78 %
Adaboost - 82%
Logistic regression - 80%
When I used voting from above classifiers for final classification, I got lesser accuracy than the case when I use... |
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