Questions tagged [distribution]

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9
votes
2answers
3k views

how to check the distribution of the training set and testing set are similar

I have been playing the Kaggle Competition and I find there is a situation that the distribution of the training set and testing set are different, so I am wondering how to check the distribution of ...
7
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3answers
1k views

Which outlier detection can detect these outliers?

I have a vector and want to detect outliers in it. The following figure shows the distribution of the vector. Red points are outliers. Blue points are normal points. Yellow points are also normal. ...
6
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3answers
2k views

xgboost: Is there a way to perform regression on rates/percentages data?

I have a dependent variable, $Y$, that is made up of rates/percentages data, so each value is between $0$ and $1$. I was attracted to the xgboost library because it allows focusing in on specific ...
6
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2answers
9k views

Plotting different values in pandas histogram with different colors

I am working on a dataset. The dataset consists of 16 different features each feature having values belonging to the set (0, 1, 2). In order to check the distribution of values in each column, I used <...
6
votes
3answers
633 views

Regression: How to deal with positive skewness in continuous target variable

I'm working on a regression problem. My aim is to "learn" the distribution of a continuous target $y$ as good as possible to make predictions. My model looks like: $$y_i=\beta X_i + u_i.$$ $y$ is ...
5
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3answers
915 views

Boxplots or violinplots?

This is quite a general question, perhaps somewhat opinion-based. In most papers people use boxplots to visualize a certain distribution, yet violinplots are able to give more information. ...
5
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1answer
2k views

How to estimate the mutual information numerically?

Suppose I have a sample {$z_i$}$_{i\in[0,N]}$ = {($x_i,y_i$)}$_{i\in[0,N]}$ which commes from a probability distribution $p_z(z)$. How can I use it to estimate the mutual information between X and Y ? ...
4
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2answers
4k views

Working with Data which is not Normal/Gaussian

What happens if my data/feature is not normal? Can I still use machine learning algorithms to utilize such data for predictions? I noticed in many data sciences courses, there is always a strong ...
4
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2answers
646 views

Why do seaborn.dist and pyplot.hist generate two different looking histograms on the same data?

I'm looking at telecom customers data. Two of the variables I'm looking at currently are: Monthly Charges - The total amount charged to the customer monthly. Is Senior Citizen - Whether the customer ...
4
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1answer
4k views

How can I plot/display a dataset or an image distribution?

I want to view a specific image or a dataset's distribution, and see if they are different. Does simply writing something like : ...
4
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3answers
915 views

How to predict whether or not a customer will renew

I have a dataset of customer contracts that specify a start date and if applicable an end date. Each month a customer is up for renewal. Below is an example of how the data is organized in excel: <...
4
votes
2answers
47 views

Is it possible to train probabilistic model to return several distributions?

I have nonlinear data of function y(x), which is let's say parabolic. At some points of x there are several y's (look at the picture). Is it possible to train a probabilistic model to return several ...
4
votes
2answers
139 views

Standard Deviation for Z-scores

I have a set of data that I'm trying to generate a z-score with. I know I need standard deviation as part of my calculations. I am using the formula of: $\sigma = \sqrt{p * n * (1-p)}$ My data is ...
4
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3answers
13k views

Transform a skewed distribution into a Gaussian distribution

I have a skewed distribution that looks like this: How can I transform it to a Gaussian distribution? The values represent ranks, so modifying the values does not cause information loss as long as ...
3
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1answer
451 views

Confidence value for face recognition

In the context of face recognition I have the following histogram: blue bins count the comparison distances for "self matches" (comparing two images of the same person). Orange bins count the ...
3
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1answer
1k views

Plotting Weibull distribution on Wind Speed

I have a 720 hourly set of wind speed and wind direction data and I want to fit the Weibull Distribution on it. After searching for some time, I wrote the following code in Python to get my ...
3
votes
1answer
275 views

Shifted feature distribution across different datasets

I am trying to validate a classifier using two different training and testing datasets. The feature I am considering is a feature constructed doing the fold-change between two original features, i.e. ...
3
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2answers
33 views

evaluation metrics for multiple values per session

I have an application that executes my foo() function several times for each user session. There are 2 alternate algorithms that i can implement as "foo" function and my goal is to evaluate them based ...
2
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2answers
89 views

How this visualisation was made?

I really like how this visualization represents the survey participants. Is any tool for that? (Or R/python library?)
2
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2answers
383 views

can I say that my variable is "approximately" normally distributed?

I am studying a variable on 50000 observations, I have applied a cox box transformation to make it normal, but even with transformation the kolmogorov smirnof and the anderson darling test tells that ...
2
votes
3answers
1k views

Is there a cost associated with converting Koalas dataframe to Spark dataframe?

I know that pandas works "under the hood" with numpy arrays stored in dictionaries. In contrast, Koalas works with the underlying Spark framework. Does that mean that there is no extra cost associated ...
2
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2answers
660 views

Fitting a distribution to data

I have a large data set of property values at two points in time. I have calculated the change in value between those two points. I want to assess which distribution most closely matches the variation ...
2
votes
1answer
1k views

Normal distribution instead of Logistic distribution for classification

Logistic regression, based on the logistic function $\sigma(x) = \frac{1}{1 + \exp(-x)}$, can be seen as a hypothesis testing problem. Where the reference distribution is the standard Logistic ...
2
votes
1answer
454 views

How to resample one dataset to conform to the distribution of another dataset?

I have two datasets with 20 features, but with different feature distributions (DS_A and DS_B). How can I sample the DS_A to make its distribution similar to DS_B, with respect to multiple features?? ...
2
votes
1answer
30 views

Generating random numbers from best probability distributions?

I have done some statistical distributions on real-world data. The distribution fitting gives me the below results (lognormal fits the best on data based on chi-squared test): ...
2
votes
1answer
938 views

Why do train, test, validation datasets need to have the same distribution?

I've found a lot of martial on how to deal with differently distributed train/test/validation data sets, however I'm struggling to find out why they they need to have the same distribution. Can ...
2
votes
2answers
144 views

How to visualize change in a distribution with a few outliers that account for a very large percent of the total?

I'm working on an edtech product where some of our traffic lands on webpages about textbooks. Textbooks belong to subjects like Algebra, Calculus and Spanish. In each of our subjects, we have "...
2
votes
1answer
168 views

Does classification of a balanced data-set lead to any problem?

So I came across a bioinformatics paper, where I found a line which says: One potential problem with using a training set with equal numbers of positive and negative examples in cross-validation ...
2
votes
1answer
635 views

Normal distribution and Random Forest

I have big table in dataframe (600k rows) which has y column (the variable I want to predict) and other 4 other columns that are the X. I have run RF regressor and I got score of 0.87 when I run it ...
2
votes
1answer
43 views

Synthetic time series generation according to some distribution

I'm trying to develop a change detection model that uses sliding windows. Given a time series with some features I've a sliding widows that analyses that time period and compares with a successive ...
2
votes
1answer
26 views

Testing for gender composition between groups

I did kmeans with k=4 and I would like to find out if there are any differences in the composition of gender between the 4 clusters. Do I use Fisher's Exact Test of Independence? Is there any ...
2
votes
2answers
6k views

When to use t-distribution instead of normal distribution?

According to the Student's t-distribution wiki article the t-distribution is used instead of the Normal distribution "when estimating the mean of a normally distributed population in situations where ...
2
votes
1answer
193 views

Stratified Sampling Variable Choice

I am trying to do stratified sampling in R to sample from my data and one of the parameters is group, which takes variable names to sample from keeping same initial distribution of the data set. Is ...
2
votes
2answers
326 views

Machine learning learn to work well on future data distribution?

This is based on my limited machine learning scope and experience, so correct me if I'm wrong. Many of the currently used machine learning models (SVMs, boosted trees, DNNs) work under the assumption ...
2
votes
1answer
756 views

Methods / Algorithms for rank scales based on cumulative scoring

Say you have an organization that requires employees to participate in a Q&A site similar to StackOverflow - questions and answers are voted upon, selected answers get extra points, certain ...
2
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0answers
8 views

Measuring the distance between data points based on mutual linkages

How to measure the distance between two data points (or: nodes?) based on their mutual share of linkages? I don't know the technical term for that, so here is a fictitious example from scientific ...
2
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0answers
32 views

Non-Gaussian like distributions - Classifier of source data fails on target data

I ask you for help on a classification problem (classes are represented by the numbers 0,1 and 2). All features are extracted from time series data (fundamental is sinus shape). I have a source ...
2
votes
1answer
173 views

Normal vs Uniform Distribution for machine learning

I have a dataset that follows Zipf's law such that the majority of the values are concentrated at one end, with the remaining items containing a very small percentage. Training on the dataset as is ...
2
votes
2answers
241 views

A/B Testing (Binomial Distribution vs Random Distribution)

When performing an A/B test for the number of clicks for users viewing (each view is an impression) two variants of an ad, a binomial distribution can be assumed where each variant has a constant ...
2
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0answers
54 views

How to estimate the marginal distribution of a class with respect to one predictor in a classification task?

I have a dataset with a binary dependent variable $y \in \{0,1\}$ and a set of predictors $x1,x2,..,t$. Here, $t$ is the time in minutes (in 24 hrs, that is $t \in (0,1440)$). I want to estimate the ...
2
votes
1answer
96 views

Co-joining multi-peak histograms

I am analysing a bunch of data files which represent responsiveness of cells to addition of a drug. If a drug is not added, cell responds normally, if it is added, it shows abnormal patterns: , . We ...
2
votes
0answers
513 views

difference between normal skewed distribution and skewed distribution [closed]

From what I've read normal skewed is a distribution that has all the properties of normal distribution and is skewed: according to this resource:https://www.statisticshowto.datasciencecentral.com/...
2
votes
1answer
85 views

How to combine data having similar distribution?

I have a collection of time series data with data points of around 2 years of daily data. I am thinking of a way to increase the number of data points in it so that the neural network gets a better ...
2
votes
1answer
50 views

How to scale or standardize data that is mostly 0 (ranges from 0-1)?

I am relatively new to data science and big data munging in general. I currently have various columns of data that range from $0-1$, but most of the values in each ...
2
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0answers
582 views

How to create a prediction interval with the fact that the residuals follow a specific distribution (in python)

I am looking at a software development pipeline where I am predicting the lead time of different products flowing through the pipeline. After applying a boxcox transformation on the lead time (...
2
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0answers
176 views

Wasserstein distance between Gaussian and the empirical distribution

Wasserstein distance between two gaussians has a closed form solution. Does the same hold for the distance between a Gaussian with a fixed variance(say 1) and the empirical data distribution? ...
1
vote
1answer
760 views

A2C Continuous for Pendulum-v0 working implementation, negation for loss and entropy calculation

very good implementation of A2C continuous for Pendulum-v0 Code has snippet to stop execution when mean of last 10 or 20 is higher than -20 but the results look like: ...
1
vote
1answer
106 views

How often do we see normally distributed data

I am having difficulty in exactly understanding several statistical tests, such as the t-test and ANOVA test. These tests require that the data we use be normally distributed. However, whilst ...
1
vote
1answer
73 views

What is a distribution-wise asymmetric measure?

I was trying to understand KL-Divergence, $$D_{KL} \langle P(X) \Vert P(Y) \rangle,$$ and was going through its Wikipedia article. It says the following In contrast to variation of information, it is ...
1
vote
1answer
92 views

How to find the best fitting parametric distribution for an empirical dataset (stock returns)?

Given some real-valued empirical data (time series), I could convert it to a histogram to have an (non-parametric) empirical distribution of the data, but histograms are blocky and jagged. Instead, I ...