Questions tagged [nonparametric]
Use this tag to ask about the nature of nonparametric or parametric methods, or the difference between the two. Nonparametric methods generally rely on few assumptions about the underlying distributions, whereas parametric methods make assumptions that allow data to be described by a small number of parameters.
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Can a Gaussian Process predict random events?
I know that we can use Gaussian processes effectively for function approximation and regression. However,suppose there is a sequence of points in time $S = \{s_1, s_2, \dots, s_n\}$, where $s_i$ can ...
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ACME Significant in Mediation analysis, but not Proportion Mediated and Fitting terminated with step failure warning
I am running a series of mediation analyses in R using the mediation package and the following code:
...
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Biased Sampling from a Non-Normal Dataset
For my analysis, I'm interested in a particular subset from a non-normally distributed population. I would therefore like to generate a sample from that population. The sample will have drastically ...
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Estimation of bivariate function with one variable being constricted
Suppose the following classical supervised regression setting,
$$y_{i} = f(x_{i}) + \epsilon_{i}, \quad i=1,\cdots,n,$$
where $\epsilon_{i}$ are i.i.d. zero mean Gaussian noise.
The above regression ...
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U -statistics for bi variate sample problem
Let $(X_1, Y_1), (X_2, Y_2),....,(X_n, Y_n)$ be iid random variables with joint distribution function $F(x, y)$ and $F(x), G(x)$ be the marginal distribution functions of $X_1$ and $Y_1$ respectively. ...
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Can I aggregate several continuous variables into percentages and then compare those percentages between groups?
I have a dataset with the concentrations of several lipids. I'm interested in finding lipids that are altered between two conditions, but the lipids are not indepentent from each other and the ...
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How to compare peak location and tail length of two different distributions?
I have the distributions of the fraction of people in each income bracket in a town in 1990 and 2020. The total sample size is the same in both, and assume that the incomes have been adjusted to ...
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Asymptotic distribution of $U$-statistics
Let $(X_1, Y_1), ...., (X_n, Y_n)$ be iid random vectors with marginal distributions functions $F(x)$ and $G(x)$ (both are continuous distributions) respectively such that $F(0)=G(0)=\frac{1}{2}$. ...
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Can I use Mann-Whitney U test for within group analysis?
I am conducting a within-group study where participants rate the perceived helpfulness of ideas on a Likert scale (DV) across two different days (Day 1 and Day 2), serving as the independent variable (...
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Statistical test for small non-parametric dataset with more than 2 dependent groups
I’m trying to figure out the most appropriate test to use for a small water quality dataset (n = 10 sampling visits at 6 river sites, upstream to downstream) with the following characteristics:
-not ...
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How to determine goodness-of-fit between non-parametric 2d-datasets
Lets say I have a set of paired x' and y' values and I have a N sets of reference values also consisting of paired x and y values. I would like to determine which reference set best matches by x'y' ...
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Estimate the likelihood of two continuous samples of unknown distribution
Consider two continuous and unknown distributions
$$X : {x_1, x_2, ..., x_n}$$
and
$$Y : {y_1, y_2, ..., y_n}$$
both can be tagged as time series with $n > 8000$.
I need to estimate the likelihood ...
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About regression analysis with categorical variables
Suppose my dependent variable is a continuous variable and is normally distributed. And I have three IVs: one is a continuous variable, and the other two independent variables are categorical. What ...
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Identifying the type of missing data and the post hoc test that can be carried out for Skillings Mack test
I have a non-normal paired sample dataset. Each row represents a dog that has been tested for an experiment. Each dog was provided with three cues (treatments): 5s cue (aka only face cue), vocalone (...
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Implementing Convolution Function for Gaussian Kernel in Python for PDF Estimation
I am currently working on estimating a probability density function (PDF) nonparametrically using a Gaussian kernel. My goal is to determine the optimal bandwidth $h$ that minimizes the cross-...
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Deriving Sample version of Anderson Darling test statistic from the theoretical version
In literature, I have seen two types of Anderson-Darling test statistic. One is expressed as
$A_T^2 = n\int_{-\infty}^{\infty}\frac{(F_n(x)-F(x))^2}{F(x)(1-F(x))}dF(x)$ and the other is given by $A_s^...
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$U$-statistics and their limiting distributions
Let $X_1,X_2, . . . ,X_n$ be i.i.d. observations from a continuous distribution
$F$. Consider the parametric function $\mathbb{P}([\text{min}(X_1,X_2) > X3])$. Find the U-Statistics and its ...
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Relation between gini coefficient/accuracy ratio and roc_auc_score when there are many identical predictions
I have been working on ranking metrics related to various estimators lately, and cam a across a curious phenomenon related to the Gini-coefficient which I would like to understand better.
I will start ...
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Doubt on non-parametric ANCOVA with two groups and pre-post scores and pre scores (baseline) as covariate
I have used a non parametric ANCOVA to analyze scores of a questionnaire (BSCS) with factors: Type of intervention(A and B) and timepoint (pre- and post) as well as baseline (same distribution as pre-)...
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Help selecting an interpretable model to measure the impact of customer journey touchpoints on satisfaction
Context
I'm working on a project where I need to undestand the impact of customer journey touchpoints on satisfaction. My goal is to create an interpretable model rather than a purely predictive one, ...
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What test should I perform given repeated measures of one subject in three time periods?
I have data that represents the measurements of the concentration of PM particles in the air at different times (every hour of every day from 2018 onwards), and I am supposed to test whether the rules ...
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Nonparametric way to perform ANOVA of linear mixed model for small sample and power calculation
I have a small data where there are 3 groups (A,B,C) and 5 participants from each group. All of those participants are measured 6 times on each of 7 different exams, so each participant get 6*7=42 ...
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Does taking the ratio of Empirical Distributions (histogram bins) show their differences?
Background
I have two Empirical distributions, both derived from social media data.
The first represents a broad sample of ~4.8 million posts and the number of followers each post author has. The ...
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Fisher information or Bayesian Uncertainty for non-parametric distributions
This question sounds ridiculous, let me clarify motivation:
Fisher information & Bayesian inference uncertainty seemed very cool to me because they can effectively tell you "how ...
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What test do I use when comparing multiple dependent groups that are non-parametric?
Basically, I am comparing outcomes in a variable that applies to everyone in a field to each subcategory of the group (e.g., average annual pay for all nurses versus annual pay for all of the ...
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Linear model for maximizing rank correlation between observed and predicted response
linear regression is modelled as
$$Y = X\beta + \epsilon$$
for response variable $Y$ (vector), design matrix $X$, and iid Gaussian noise $\epsilon$ (vector).
instead of minimizing the mean squared ...
- 2,480
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Appropriate non-parametric test for repeated measures in two groups
I have two different study groups (A: intervention, B: no intervention/control), each around n~220 patients. Now, every patient has had monthly check-ups for 12 months where blood was drawn, so for ...
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Statistical significance test on 2-sample percentages
In the context of my thesis, i have created a corpus in order to compare the use of "z" vs "s" in specific words like organisation, organised, recognise, authorise etc.
I have ...
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Mixed design experiment: median reduction or linear mixed model?
I collected data from an acoustic localization experiment with a mixed-design, where the factors are populations (one with hearing devices (HA) and one with cochlear implants (CI)), and conditions, ...
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Multiple IVs and DVs with non-normally distributed data
I am performing a research study aiming at answering the research question:
How does job design satisfaction differ between employees working in hybrid and remote work arrangements?
For that I ...
