Questions tagged [statistics]
For statistical questions related to bioinformatics. If the nature of question is purely statistical, consider stats.stackexchange.com instead.
161
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How to get enriched pathways in the data using continous statistic measure?
I was doing pathway enrichment analysis using the below code
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Heritability estimate in LD Score Regression (LDSC)
I am trying to replicate the heritability estimates based on the insomnia GWAS summary statistics using LDSC. However, I have encountered a problem as my estimates seem to be only about half of the ...
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Simes method in R
I have data that looks like this: 3 column SNPs their gene based on Annovar and a p-value for every SNP. What I would like is to aggregate the p values for every gene.
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GLM for multinomial using r - results of genotyping
I have next data:
age - how old is person, e.g. 17 or 25
bmi - body mass index, e.g. 18.25 or 29.35
rsXXX - results of genotyping in rs(point), e.g. rs10852521: C/C, C/T and T/T
I devide all data ...
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Using Multi-Dimensional Scaling (MDS) to produce a vector in order to account for patient bias when constructing DGE lists from RNA-seq datasets in R?
I am currently working on my PhD and as part of my thesis, I intend to analyse gene expression within multiple sclerosis (MS) lesions by looking at RNA-seq datasets on Gene Expression Omnibus (https://...
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153
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How to z-transform Fst and -log(p) values for genome wide selection scan?
I saw in the literature a lot genome wide scans showing $F_{ST}$ values in a 'z-transformed' format which seems to be bounded between 0 to infinity.
Examples are found easily searching for 'genome-...
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70
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How to statistically test the strength and weakness of a correlated pair?
Subset of df before groupby looks like
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Genomic inflation factor distribution (lambda)
Considering that the p-value of a chi statistic(df=1) is uniform, the expected genomic inflation factor is λ=1. I show its calculation in R with the next chunk of code:
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Understanding regularization step in Meta-cell pre processing
I'm reading through this paper: Baran, Y., Bercovich, A., Sebe-Pedros, A., Lubling, Y., Giladi, A., Chomsky, E., ... & Tanay, A. (2019). MetaCell: analysis of single-cell RNA-seq data using K-nn ...
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Multivariate analysis of cell culture bioprocess
I am seeking statistical support for the following bacterial growth time series.
In the lab, we have cell cultures growing in bioreactors. Every day we measure the concentration in mmol-1 of a set of ...
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Non-parametric, background-based tests on proteomics data from Proteome Discoverer v2.5?
I am new to proteomics analysis, so apologies if my question is silly! For context, I am working with proteome samples from the postmortem human brain for a case-control study.
Our lab generally ...
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29
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hypergeometric test in R
I have 15800 genes in a dataset, of which 5233 are differentially expressed, of which 1707 are upregulated. I have a second population of 17763 genes, I have selected a group of 119, of which 65 are ...
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Clustering individuals by gene presence/absence
I have a binary matrix with individuals as row names, and gene name as column name.
So, if the gene is present in an individual, we have 1, otherwise 0.
I would like to cluster individuals based on ...
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Regarding chi square?
I need some suggestions regarding an analysis. I might be wrong as I have no stats background.
I have list of exon with differential usage across samples. I can find lots of denovo mutations from both ...
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29
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MLPE in lmer (lme4 in R)
I am trying to conduct some landscape genetics analysis by testing association between landscape resistance matrices and pairwise genetic distances using linear mixed models.
When I run lmer package, ...
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How to select the best ligands in a virtual screening matrix
I have the results of a virtual screening experiment using docking simulations with Autodock Vina. The result is a matrix of 7 (proteins) by 28000 (ligands) with the calculated binding energies for ...
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How to calculate distance matrix from fasta?
I’d like to perform the following, but I am having difficulty.
I want to convert amino acid sequences in multifasta files into matrices (or vectors) with Euclidean distance and Pearson correlation ...
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Statistical significance of pairwise protein sequence alignment
I have identified a conserved region in a protein I'm studying, by doing multiple sequence alignments against a dozen of its orthologs. I've then found that this region also aligns relatively well ...
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52
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statistical test and visualization of genes present in an experiment
I have a list of genes (n = 120) that are involved in breast cancer. And I have a list of differentially expressed genes (n = 70) that are present in the breast cancer gene list. My question is: Are ...
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Calculating the effect of differences between two groups of nucleotide sequences at every position
I'm investigating two different groups of short nucleotide sequences. The behaviour of a certain DNA-binding protein is likely influenced by common differences between these two groups leading high or ...
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282
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Why all values become 1 after dcast?
I am reshaping my dataframe as follows.
I want to set the Wavelength column as the column names with the code as follows.
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Why is the p-value significance threshold for HLA association tests $5*10^{-8}$? [closed]
Typically, a p-value of $p<=5*10^{-8}$ is used for genome-wide association testing, as there are roughly $1/p$ independent LD blocks in the human genome, so it correct for multiple testing across ...
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What is the best way to perform batch ajustment between two experiments?
I have duplicate drug efficacy experiments performed six months apart. I would like to know what is the right way to perform statistical analysis to understand fold changes after treatment with a drug....
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Association analysis for methylation beta value and phenotypes in R
I am trying to learn how to do association analysis of methylation array data with numerical trait like body weight, eGFR.
As I have seen some of the publications, methylation data association with ...
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How to do enrichment analysis with scipy.stats.hypergeom.sf function
I want to do pathway enrichment analysis in python using scipy.stats.hypergeom.sf function to select pathways that are significantly enriched in at least one tissue....
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45
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IBM SPSS- 2-years survival of cohort
Over the past few months I have been retrospectively analyzing patient files for my master's thesis in medicine. As the median overall survival of my cohort is low, I have decided that I want to ...
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4
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136
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LD Score Regression Derivation hard to follow
I am trying to understand the derivations from Sullivan et al. (2015) in the Supplementary Material. There, it is mentioned in the first page that the least squares estimate of the j-th SNP effect, ...
2
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2
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159
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Comparing differential expression across samples - is batch effect correction needed?
I have a bulk RNA-seq dataset made up of control and treatment conditions for a range of cell lines. This dataset was generated in two batches, such that the cell lines are split between batches but ...
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2
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44
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How Does Cox Proportional Hazard Model Describe Interaction between Covariates
I have read STDHA and the documentation for the coxph() function in R. I understand that the cox PH model explores how different covariates simultaneously impact survival. Based on the Lung data ...
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90
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What statistics can I use on qPCR data composed of several runs if all normality tests fail on the dataset?
I have >100 qPCR experiments that I'd like to analyze together, each containing the same set of genes (10 genes of interest and 2 reference genes).
I have four different samples (untreated & 3 ...
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101
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Linking UK biobank patient IDs with their corresponding genetic data
I am analyzing ukbb data and I have patient IDs for both cases and controls. Now I want the genetic data of all patients based on their IDs.
I am trying to test with chromosome 5 as I have both bgen ...
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1
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70
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Understanding the different designs in DESeq2
I am using DEseq2 and trying to understand the results obtained using different models.
I have a data design with 2 genotypes and 2 time points.
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5
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1
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171
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UPGMA computation
The unweighted pair group method with arithmetic mean (UPGMA) is a hierarchical clustering method, for example used in phylogeny. In a phylogenetic tree it would result in a global molecular clock ...
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1
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Statistical or performance test for genomic intervals between 2 samples
Is there an appropriate statistical or performance test to perform when I want to compare genomic intervals between 2 samples. Sample A is the the benchmark of comparing the intervals and sample B is ...
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Adjusted P-value from DESeq2
What does the padj really mean? I believe it's a BH method, where it attempts to quantify the likelihood of a "false positive" but I am not sure. Also, what does it mean if the resulting ...
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General Question: Statistical Alternatives to Oncoprint
I am a computational genomics student who has recently joined a research lab as an RA. We often work with oncoprints (comuts/heatmaps), and we visualize molecular signatures by reorganizing the comut. ...
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Question about the practical relevance of chromosome position and p-value
Article of interest: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3023908/#SD1
Referring to Figure 2b of that article, if I understand correctly, the x-axis refers to the position of each variant in a ...
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Where can I find a basic example for testing association between a phenotype and each of the variants of a chromosome?
I am a statistics student trying to find data suitable for a particular method. From what I have read so far, it is of interest to determine if variants within a chromosome are associated with a ...
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2
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What is the tP statistic from ANGSD?
We were looking for genetic diversity in the exon level of an MHC transcript and analysing the data under ANGSD (Analysis of next generation Sequencing Data) written in C++
We used ANGSD to calculate ...
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P value recalculation from multiple analysis (Transcriptomics)
I've done a differential expression analysis with transcriptomic information (microarrays and RNAseq) from different datasets by applying for some of them t-test and for the rest Wald-test. I've got ...
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383
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How to create Beta Diversity distance boxplot
I'm trying to generate boxplot from Beta diversity boxplot between two conditions from a phyloseq object.
I have a Morisita-horn distance generated by vegdist fonction :
...
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How to compare Log2 Fold Change values
I have 5 sets of Log2 Fold Change values pulled off DualSeqDB. Each of the 5 groups corresponds to a different microbial taxon. Within the 5 groups, there are many Log2 Fold Change values, each ...
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How to decide between standardized mean difference (SMD) and log2fold change (log2FC) before doing meta-analysis?
I want to do meta-analysis of alpha diversity between test and control groups across 10 different populations. I want to see what is the summed effect (pool effect) of intervention between the two ...
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What are the best practices for comparing .seg copy number outputs from iChorCNA to VisCapCancer?
I have shallow whole genome sequence data that I used the tool iChorCNA to find the mean copy number segmentation per region. The tool produces a seg file and can be seen here: https://github.com/...
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Tajima-Nei Distance estimate with BioPerl
I have been trying to estimate Tajima-Nei distance for my data (link below). The output is s phylogenetics distance (pairwise) matrix which accommodates a detailed transition transversion and the ...
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How do you find differences when your metagenome sample size is small?
I received a matrix of genomics features (KEGG annotated metagenomes) abundance from 6 samples belonging to 2 groups. My collaborator is interested in finding differences between the two groups.
The ...
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How is the t-statistic value calculated in GEO2R or Bioconductor?
I was trying to calculate t-statistics using Python's scipy and numpy as np-
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1
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107
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Multiple box plot
I am using below code to plot multiple box plot but I am still struggling to understand how I can add whisker to box plot and how to change sample order like in this figure SampleType?
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