Stack Overflow
Stack Overflow

Questions tagged [kruskal-wallis]

The Kruskal–Wallis one-way analysis of variance by ranks is a non-parametric method for testing whether samples originate from the same distribution. It is used for comparing more than two samples that are independent, or not related.

102 questions
2
votes
2 answers

R: Kruskal-Wallis test in loop over specified columns in data frame

I would like to run a KW-test over certain numerical variables from a data.frame, using one grouping variable. I'd prefer to do this in a loop, instead of typing out all the tests, as they are many variables (more than in the example…
RmyjuloR
  • 369
  • 1
  • 4
  • 13
2
votes
0 answers

How to control method of ranking for Kruskal-Wallis test in R?

In my experiments I tried different set ups to balance the distribution between two tasks. Each set up was run 32 times. I got the following task distributions [ratio from 0 to 1 of tasktype1/(tasktype1+tasktype2)]:…
Basiti
  • 143
  • 1
  • 11
2
votes
1 answer

create vectors for Kruskal-Wallis H-test python

I have dataset as below df = pd.DataFrame({'numbers':range(9), 'group':['a', 'b', 'c']*3}) group numbers 0 a 0 1 b 1 2 c 2 3 a 3 4 b 4 5 c 5 6 a 6 7 b 7 8 c 8 i want to create vectors a = [0, 3, 6] b = [1, 4,…
Edward
  • 4,443
  • 16
  • 46
  • 81
2
votes
2 answers

How to deal with missing values in Kruskal-Wallis test in Matlab?

The Matlab documentation seems unclear about how to ignore missing data when using kruskalwallis, the Kruskal-Wallis (or any other related) test. The same goes for unequal group size.
user3503398
  • 45
  • 5
1
vote
1 answer

What is the quickest way to apply a statistical analysis such as Kruskal-Wallis from scipy module in python to an entire polars dataframe?

I want to apply Kruskal-Wallis statistical analysis on every numeric column of polars dataframe & return a new dataframe where every column holds the result of the KW. My dataframe consisting of a large number of rows & columns looks like…
megha
  • 23
  • 4
1
vote
0 answers

Performing a Kruskal-Wallis test

I'm trying to understand if there is a statistical difference between Policy support scores (PS_score) and Income. I have never done one before so I'm hoping someone can see if I have done it correctly? Also, if there is anything else I should do to…
Lucy Larner
  • 11
  • 1
1
vote
1 answer

For loop in R: error in model.frame.default()

I'm quite new to loops so please be patient with me :) I have calculated alpha indices (Observed, Shannon, InvSimpson, Evenness) for which I want to perform a Kruskal-Wallis statistical test with the variable Month of my table. My table (df) looks…
sophiethomas
  • 63
  • 6
1
vote
1 answer

Pairwise comparisons with weights in R

I ran a weighted Kruskal Wallis test using the survey package in R. The result shows that there is a significant difference between groups, but does not specify between which ones. Therefore, I´d like to follow up with weighted pairwise comparisons…
seb-29
  • 51
  • 2
1
vote
0 answers

same data gives different p-values for kruskal test

I've defined 3 variables that are " x, y and z". Tried to kruskal test these independent variables. P-Value comes out different in python and r. Have any ideas? in python from scipy import stats import numpy as np x = np.array([22.293, 23.621,…
Joseph_Wesleyan
  • 37
  • 6
1
vote
0 answers

Compact letter display after Kruskal-Wallis-Test

I'm trying to evaluate some data for my thesis. I can use R to build a boxplot and conduct the statistical test just fine, and I can do the compact letter display manually... but this time I simply have too much data to do it this way. I'm plotting…
Liz
  • 11
  • 1
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

Getting pairwise effect sizes

I am trying to get pairwise comparisons of effect sizes. I can do this with coh_d, however, it gives me repeat comparisons. For example, in the following code, setosa vs. versicolor is the same as versicolor vs. setosa (apart from the flipped…
hugh_man
  • 399
  • 1
  • 6
1
vote
0 answers

Test differences in multimodal distributions for different groups in R or Python

I am analyzing data from 3 different gait speeds. For each group/speed, I am determining specific value called "angle". Each group has different sample size. So, I need to compare multimodal distributions and I would like to statistically test…
Dori
  • 53
  • 4
1
vote
1 answer

Trying to do a Kruskall Wallis post hoc test in python but stats are different?

I'm struggling to figure this. I'm new to python coming from an SPSS background. Essentially once you've done a Kruskal Wallis test and it returns a low p-value, the correct procedure is to do a post hoc Dunn test. I've been struggling to figure out…
tankgirl2810
  • 11
  • 1
1
vote
1 answer

Kruskal-wallis in R

I have tried to perform the Kruskal-Wallis test, but I am not sure if the data is ordered correctly, therefore, I do not know if the result is correct. I still do not know how to verify that it is correct, I do not know if you can help me identify…
loreniaolivas
  • 11
  • 1
  • 2
1
2
3 4 5 6 7