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Questions tagged [statistics]

Consider whether your question would be better asked at CrossValidated, a Stack Exchange site for probability, statistics, data analysis, data mining, and machine learning. Code Review questions on statistics should be about implementation and working program review, not about theoretical discussions of statistics or research design.

2
votes
1answer
41 views

Select optimal piecewise regression fit

I'm making a program which fits a piecewise linear regression with up to 4-5 breakpoints in the data, and then deciding how many breakpoints is best to prevent over and underfitting. However, my code ...
4
votes
1answer
53 views

Pick the best combination of n choose k models

Algorithm Let \$M_0\$ denote the null model which contains no predictors. This model simply predicts the sample mean of each observation. For \$k=1,2,\ldots,n\$: Fit all \$n \choose k\...
4
votes
1answer
33 views

Entropy calculation function in Haskell

I've written a function in Haskell for calculating the entropy of a collection. I'd like feedback on how the function could be rewritten to be more flexible/reusable, and also how to profile the ...
2
votes
0answers
56 views

Bias-corrected percentile Bootstrapping Optimization

I have never posted to this forum, but was referred here. I need some help printing key iterations as well as optimizing my code for run time. If someone had some time to help/explain how to correct ...
1
vote
0answers
28 views

Flagging out-of-stock items

I wrote a function that iterates over 3 parameters to spot out-of-stock items. To illustrate this I'll draw an example: suppose that the product 10 in store 2 for an offer named "super5" is following ...
3
votes
0answers
15 views

TensorFlow regressor to predict probability of winning, given a current score

This is a TensorFlow regressor that tells me that if you get x score, you will have x% to win a game in x game(game is not important). Doing this as a project to learn tensorflow. ...
6
votes
2answers
140 views

Finding median from unsorted array with duplicate elements without sorting it

I am implementing a method to find the median of an unsorted array using a counting sort. I would happily go for a median of medians or selection algorithm for better performance but they are ...
2
votes
3answers
101 views

Statistical methods using PHP (mean, co/variance, standard deviation, skew, correlation)

Functionality This class has a list of statistical functions such as mean, variance, standard deviation, skewness, and it works okay. These functions are applied to arrays of charts data. It is an ...
3
votes
3answers
119 views

Computing average duration per user from a large CSV file that doesn't fit in memory

We have a large log file which stores user interactions with an application. The entries in the log file follow the following schema: {userId, timestamp, actionType} where actionType is one of two ...
2
votes
1answer
65 views

Groovy script to get average price per group from different data arrays

I've been trying to learn Groovy lately and I tried to solve a problem which involves designing a routine that will calculate the average Product price per Group. I have the following data: ...
6
votes
1answer
68 views

Monte Carlo errors estimation routine

I would value your opinion on the following piece of code. I am rather new to both Python and Monte Carlo analysis, so I was wondering whether the routine makes sense to more experienced and ...
3
votes
1answer
61 views

Generating random number from a binomial distribution

In my application of Monte Carlo simulation, the crucial part is to generate a random number from a binomial distribution with parameters n = size and p = 0.5. Here is my current implementation ...
2
votes
1answer
77 views

Welford's online variance calculation algorithm for vectors

I'm developing a face recognizing application using the face_recognition Python library. The faces are encoded as 128-dimension floating-point vectors. In addition to this, each named known person ...
3
votes
1answer
37 views

Sample size, P-values (its relationship), and data visualization with plots. ggplot and T test

We know that P-values (within t-test context as an example..) is highly sensitive to sample size. A larger sample will yield a smaller p-value remaining everything else constant. On the other hand, ...
8
votes
1answer
48 views

Python implementation of approximating the chance a particle is at a location after n steps in the cardinal directions

Recently, I became very interested in a probability practice problem in my textbook for my class. I decided to implement it in code and I think I got most of it implemented. Right now, I'm hoping to ...
3
votes
1answer
84 views

Program which accepts grades and prints grade distribution

I'm doing the MOOC Java course (CTRL+F "distribution"): The input of the program is a set of exam scores of a course. Each score is an integer. When -1 is entered, the program stops asking for ...
3
votes
2answers
76 views

Constructing a cumulative distribution function from a histogram

During some running process, a histogram of values shall be build up. When done, the CDF shall be derived from it and used to get the quantiles for some values. My current implementation looks as ...
3
votes
1answer
68 views

Evaluating association strengths of items

I have a list of animals with their counts: ...
2
votes
0answers
19 views

Simple data analysis for forecasting

This Python script extracts data from txt files containing raw numerical data, notably the increase average, the relative evolution and the standard deviation of ...
2
votes
1answer
68 views

Incrementing time in a discrete-event simulation of a supermarket queue

A method has been written that increments time in minutes that simulates how much time it takes to process item in a supermarket queue and if there is an empty queue, skip it and loops around to find ...
5
votes
1answer
62 views

Linear regression on points specified by the user in a GUI

Here's my take on the Linear Regression exercise from John Zelle's Python book. Open a window, let the user click on as many points as they want. Upon pressing the "Done" button the regression line ...
3
votes
0answers
43 views

Download and analyze PDFs of Congressional records

This is built with Python 2.7.15. The goal of this script is to count the number of words spoken by each Senator on the floor of Congress between given dates. It pulls from the Congressional Record, ...
5
votes
2answers
362 views

Counting consecutive selections of a given number when sampling integers in a range

This script counts consecutive number strikes of a number that you determine in a number-sequence that you also determine. I would be very pleased if this script can be reviewed in terms of ...
2
votes
2answers
77 views

Application to monitor device power levels for deviations

I have a high performance, computation intensive application that runs on a Centos 7 machine with Python 2.7.5. I'll try to explain what the application does: The application runs an infinite loop, ...
3
votes
1answer
81 views

Plots of prior and posterior distributions for a model

I have an exercise that ask to plot the prior and posterior distribution in the Poisson-Gamma model. I did it (I think it's correct) inspired in the answer of this question https://stats.stackexchange....
1
vote
1answer
74 views

Simulating data generating process correctly

My aim is to simulate the following model by means of a Monte Carlo simulation. I wonder if my R code is correct for generating the data. Could somebody check? The model: $$Y = \sum_{j=1}^{100} (...
0
votes
1answer
40 views

Generating probability table of 2-character combinations from text file in Java

I have written a probability table generator in Java to help me generate randomized girl's names for the game I am making. It reads from a text file and creates a ...
3
votes
3answers
106 views

A collection of vector functionals

I would like some feedback for a collection of what I call "vector functionals", by which I mean maps \$\ell\colon \mathbb{K}^{n} \to \mathbb{K}\$, where the field \$\mathbb{K} = \mathbb{R}\$ or \$\...
8
votes
2answers
459 views

Sparse 3D binning/histogram function

This is a function written in Python I wrote to process galaxy catalogs for cosmology research, however it is more generally applicable than just my pipeline. The goal is to take a Python list of ...
2
votes
1answer
53 views

dplyr — tidyverse, pipes, correlation, same variable across time “a” “b”

Have a look at this dataset. The"a" and "b" are used to make possible differentiate when the same variable was measured. In this case X1a and X1b access the same variable, but "a" was (suppose..) in ...
1
vote
1answer
159 views

Using dplyr and pipes for logistic regression plotting

I have successfully created a plot of a binomial glm using example data. https://sciences.ucf.edu/biology/d4lab/wp-content/uploads/sites/125/2018/11/parasites.txt The predictors of the model include ...
1
vote
1answer
60 views

Get the most frequent number and least frequent duplicate in array

This code gets the most frequent number and least duplicate number in an array. How can I optimize it and improve its performance? ...
5
votes
2answers
58 views

Simple function returning 1 if the Mean = Mode, or 0 if not

I'm trying to get better at javascript and have built a simple function that returns 1 if the mode is equal to the mean, and 0 if not. You can enter an array of numbers into the function: ...
5
votes
3answers
496 views

Count sub-sequences of an array having median lying in that subsequence itself

We need to calculate the number of sub-sequences of an array having its median lying in the sub-sequence itself. My code is - ...
1
vote
2answers
84 views

Top K frequent elements

I am working on an interview question where I need to return the k most frequent elements given a non-empty array of integers. Input: nums = [1,1,1,2,2,3], k = 2 Output: [1,2] Here is my code: <...
1
vote
1answer
140 views

Median of a Vector assignment

I've been reading Bjarne's Principles in Programming and was given some code to demonstrate the usage of vectors and how we can return specific values for certain functionality such as mean and median....
2
votes
2answers
50 views

The importance of consistency in percentage returns when investing

It is said that Being consistent in percentage annual returns leads to larger amount over time. That is for any given principal, getting 20% successively for 2 years is better than 30% for first ...
2
votes
3answers
89 views

Speed up weighted average for Leela Chess Zero

Problem: Given a vector of about 40 values m with normal error sd compute the weighted average of the values weighted by the ...
9
votes
4answers
2k views

Program to accept numbers, then calculate the mean, median, and range

I created a basic program that allows a user to continuously input values until he or she is satisfied; furthering, the program outputs the mean, median, and range. Then, the code gives you the option ...
1
vote
3answers
79 views

Printing a table of letter frequencies using Python

What is the recommended (standard, cleaner, more elegant, etc.) method in Python to get a string with all the alphabet letters? Here's three versions of code to generate a dictionary with keys as ...
2
votes
0answers
56 views

Simple linear regression of two variables

This is the code I built to implement a simple linear regression to check the impact of variable A on B. I am not interested in predicting that's why the statistical approach is important for me to ...
0
votes
0answers
56 views

Flask models for scores and statistics

I'm not sure whether I need to group a bunch of related methods in a single class or put them in a separate module. Which way would be preferable in Python? Here is what I've got so far but not sure ...
4
votes
1answer
67 views

Python program computing some statistics on Scottish geographic areas

This simple script computes some basic descriptive statistics, like mean, standard deviation, kurtosis, etc. on data column imported from a CSV file with use of ...
16
votes
3answers
2k views

Newton-Pepys, common birthdays and other probability simulations in Python 3

I have been learning Probability from Statistics 110 and trying to simulate problems that have an unintuitive answer ...
7
votes
1answer
123 views

Frequency Analysis & Chi-Squared Test

Following up on my implementation of Cryptopals Challenge 1, this is my solution to Challenge 3. Single-byte XOR cipher The hex encoded string: ...
3
votes
1answer
67 views

Statistics and calculations

I went through a series of lessons in data science using pandas and numpy. I have attempted to replicate some of the more common algorithms based on maths forumlas and psuedocode, except for the <...
1
vote
1answer
26 views

Creating the design matrices for a canonical correlation analysis

I have this code to generate symmetric matrices for testing how the design of the canonical correlation analysis I am performing works out. This is a extension of this solution Each row of the matrix ...
2
votes
1answer
48 views

Regularised regression code

I wrote some code to do regularised linear regression and it works, but I don't like the fact that I've had to double call the functions when plotting, nor the fact that I've sliced those calls to get ...
5
votes
2answers
175 views

Cross-validating Fixed-effect Model

Code Summary The following code is a data science script I've been working on that cross-validates a fixed effect model. I'm moving from R to Python and would appreciate feedback on the code below. ...
11
votes
1answer
138 views

C++ thread-safe averaging

Although having very little C++ experience, I was tasked to implement several statistics objects that are safe to be asynchronous accessed by different threads, that collect data in relatively small ...