Stack Overflow
Stack Overflow

Questions tagged [statistical-test]

A statistical test provides a mechanism for making quantitative decisions about a process or processes.

Statistical Tests

A statistical test provides a mechanism for making quantitative decisions about a process or processes. The intent is to determine whether there is enough evidence to reject a conjecture or hypothesis about the process. The conjecture is called the null hypothesis. Not rejecting may be a good result if we want to continue to act as if we believe the null hypothesis is true. Or it may be a disappointing result, possibly indicating we may not yet have enough data to prove something by rejecting the null hypothesis.

264 questions
1
vote
1 answer

How can I score how well an ellipse fits my points?

There are dozens of answers on here about how to fit an ellipse to your points, but none seem to suggest ways to quantify the fit. Here's some points and the ellipse fitted from this answer: import numpy as np from skimage.measure import…
Ninja Chris
  • 324
  • 1
  • 3
  • 12
1
vote
1 answer

Function to Conduct a Kruskal Wallis Tests for Multiple Comparison of Variables using R

Issue: I have a dataset that doesn't meet the assumptions to conduct an ANOVA, so I need to conduct a non-parametric alternative such as the Kruskal Wallis test. Overall, I have seven parameters and I want to conduct multiple pairwise comparisons…
Alice Hobbs
  • 1,021
  • 1
  • 15
  • 31
1
vote
1 answer

Is there a way to check whether chi-square or Fisher's exact test should be used and then run it automatically?

I am new to R, but I turned to it as it is the only software available to me that can perform Fisher's exact text on tables bigger than 2x2. In theory 'the chi-square test is performed only if at least 80% of the cells have an expected frequency of…
Wojciech Mrowicki
  • 31
  • 5
1
vote
0 answers

R row_wise comparison of percentages

I have a dataframe of celltype percentages within two group of patients, like in this example: df <- structure(list(group1 = c(1.7, 1.8, 1, 8.2, 0), group2 = c(3.4, 8.3, 0, 7.1, 0)),…
yakumo
  • 27
  • 4
1
vote
0 answers

Reasoning for numpy random seed in this function?

I'm following a tutorial on the usage of Python in bioinformatics. In the tutorial a Mann-Whitney U test was performed via the function below. numpy.random.seed was used in the first line after packages but nowhere else. I was wondering what is the…
Levent Düşünceli
  • 21
  • 2
1
vote
2 answers

How would I run multiple paired Wilcoxon signed rank tests over many pairs of vectors in an R data frame?

I have a dataset of 161 immune markers, each a vector in a data frame. Using R, I want to compare 78 pairs of these vectors using the Wilcoxon signed rank (paired) test. The immune markers are distinguished in their names by "_MOM" or "_CB." Here's…
cewim
  • 37
  • 4
1
vote
2 answers

How would I run a t test on 58 (variables) columns to compare 2 different data frames

I have 58 columns in each data frame that I would like to compare to see if there is a significant difference between them (individually and as a whole) as each of the 58 comprise a water basin and would be a sum of the whole, but still individually…
LARA
  • 11
  • 1
1
vote
1 answer

Statistical tests for two random datasets

I need to compare two data sets, i randomly created them in Julia, with rand. I want to know if there's some statistical test (that can be perform in Julia JuMP) that tells me how different the distributions are (having no assumptions of the…
jvm.97
  • 247
  • 1
  • 7
1
vote
1 answer

R equivalent of immediate commands in Stata (i.e. tabi ..., chi2)

Apologies in advance for this probably very basic question, but I have been struggling to find out how to do this in R. When reviewing papers, theses, etc, it is very useful to calculate p-vaules from aggregate data. I.e. you see a table and wonder…
Bjorn Blomberg
  • 51
  • 1
  • 5
1
vote
1 answer

Is there an R function that tests for spatial autocorrelation in residuals of a regression created by errorsarlm / lagsarlm / sacsarlm

My question relates to the functions errorsarlm(), lagsarlm() and sacsarlm() of the "spdep" package. I would like to test the residuals of a regression created by one of the functions above on remaining spatial autocorrelation, for example by…
moellivm
  • 65
  • 1
  • 4
1
vote
0 answers

Non-parametric testing for three way interaction effects

I'm looking for the appropriate test to perform to determine if there is a three way interaction effect on my (non-parametric) likert-scale data. My data currently has a dependent variable with values from 1-7 on a likert scale. The study includes…
Meghan Shaw
  • 11
  • 1
1
vote
1 answer

Extract p-value from an Object QuadTypeIndependenceTest and ScalarIndependenceTest from Coin Packages

Using Aids2 dataset from package MASS, I am applying Ansari-Bradley Non-Parametric Test to test Group Independency by this snippets library(coin) library(MASS) a1 <- ansari_test(Aids2$diag~Aids2$state) a2 <- ansari_test(Aids2$diag~Aids2$sex) if I…
Jovan
  • 763
  • 7
  • 26
1
vote
1 answer

Prop.test and fisher's exact test in R

I am confused about the use of fisher's exact test comparing two proportions. For example, I want to test whether there is a difference between two proportions 9/13 and 3/18. I can simply type A <- c( 9, 3) B <- c( 13, 18) prop.test(A , B) but…
sdaniel24
  • 25
  • 5
1
vote
1 answer

ANOVA P-value column in table1 package R

I'm trying to perform an ANOVA test on a data set to compare the means of different groups in a table using table1 package. In this example, at the bottom of the page, the writer performs a t-test to compare 2 means (male vs female) with a function…
ludo
  • 169
  • 1
  • 12
1
vote
1 answer

How to convert single column into normal or gaussian distribution. & find the CI of 95% & 99%

I have one column name as df['Air temperature'] (datatype-float64) I want to convert this column into normal distribution so i can use imperical rule to find 95,99% CI. or any other approach is also fine to find 95%,995 of…
Akash Desai
  • 498
  • 5
  • 11
1 2 3
…
17 18