The largest database of trusted experimental protocols

R statistical computing software

Sourced in United States

R is an open-source software environment for statistical computing and graphics. It provides a wide variety of statistical and graphical techniques, and is highly extensible. R is a language and environment for statistical computing and graphics.

Automatically generated - may contain errors

19 protocols using r statistical computing software

1

Alzheimer's Disease Genetic Risk Analysis

Check if the same lab product or an alternative is used in the 5 most similar protocols
Clinical variables from PSEN1 A79V MCs and individuals with LOAD were summarized using descriptive statistics. Continuous numerical variables were compared using the non-parametric Mann-Whitney U-test. Categorical data was compared using Fisher’s exact test. The relationship between APOE ε4 carrier status and age at symptomatic onset (AAO) was considered through a Kaplan-Meier survival analysis. Overall differences in survival were assessed using the Mantel-Cox (log-rank) statistic. Statistical analyses were conducted using statistical software (IBM SPSS Statistics 23, IBM Corporation; and R Statistical Computing Software, www.r-project.org). Statistical significance was reported when p<0.05.
+ Open protocol
+ Expand
2

Pharmacogenomics of Anastrozole Metabolism

Check if the same lab product or an alternative is used in the 5 most similar protocols
Only patients known to be compliant to drug therapy were included in the GWAS. Therefore, subjects with undetectable levels of anastrozole as well as all assayed anastrozole metabolites (anastrozole glucuronide, hydroxyl‐anastrozole, and hydroxyl‐anastrozole glucuronide) were excluded from the analysis. An additional three extreme outliers subjects were excluded who had anastrozole metabolite concentrations greater than 6 SDs above the mean. A total of 687 women remained for the final analysis. The distribution of anastrozole concentrations was right skewed, so a Van der Waerden22 transformation was applied to render the distribution normal. We used both simple and multiple linear regression models to identify clinical and demographic variables that were associated with anastrozole concentrations. For the GWAS analysis, we used a linear regression model with additive SNP effects, with European Ancestry captured by the first and second eigenvectors from a principal components analysis. The top two independent SNP signals from the GWAS were also assessed for a possible SNP–SNP interaction. Linear regression models and both line and bar plots were used to assess this relationship. All analyses were performed using R statistical computing software (version 3.0.2; https://www.r-project.org/) and Plink (version 1.07; http://zzz.bwh.harvard.edu/plink/).23
+ Open protocol
+ Expand
3

Methylation Profiling of Blood Samples

Check if the same lab product or an alternative is used in the 5 most similar protocols
Before analysis, data was subjected to stringent quality control. First, we removed all probes for SNPs and X-chromosome sites. Next, CpG sites where >23 subjects had beta values of zero, as well as sites where >3 subjects had signals below background detection were removed. Lastly, we removed probes with polymorphic CpGs that may interfere with the analysis14 (link)27 (link). This left 998 CpG loci, and 25 subjects ranging from 26 to 45 years in age (10 male and 15 female). Methylation measurements of zero were replaced with the minimum measurement for either PBMC (0.033) or BEC (0.03). All analysis was performed using the R statistical computing software (http://www.r-project.org), and statistical tests were conducted with alpha level of 0.05.
+ Open protocol
+ Expand
4

Normality Assessment and Hormone Comparison

Check if the same lab product or an alternative is used in the 5 most similar protocols
Q-Q plot and boxplot were used to check the normality of the data. One-sample t-test and one-sample Wilcoxon signed-rank test were applied as needed to test the differences of hormone measurements at both baseline and after FSH stimulation for Phase I compared to Phase II. We also tested for differences in the log fold change of E2, Inh B and insulin hormone before and after FSH. For all analysis, p values of < 0.05 were considered statistically significant. Statistical analysis were performed using the R statistical computing software (version 2.6.2, http://www.r-project.org, 2009).
+ Open protocol
+ Expand
5

Coronary Artery Calcification Genetic Analysis

Check if the same lab product or an alternative is used in the 5 most similar protocols
All statistical analyses were carried out using the R statistical computing software (https://www.R-project.org). For all transfection experiments, luciferase reporter activity levels were normalized as log2 fold change relative to the non-deletion construct baseline average. To determine if co-transfection produced a dose-dependent effect and whether there was an interaction between dose and vector type (non-deletion/deletion luciferase reporters) a two-way analysis of variance (ANOVA) was performed for each co-transfection experiment. Dose, luciferase reporter type plus a dose:vector interaction variable were included in each ANOVA. P ≤ 0.05 were considered significant. Tukey's post-hoc analysis was performed when there was significant interaction between vector type and dose.
To determine the association of the rs3045215 deletion with coronary artery calcification a linear regression model was used. The rs3045215 variant was coded as counts of the minor (deletion) allele, i.e., HNR = 0, HET = 1, and HR = 2. The analysis was split by sex and CAD case status with smoking status and age included in the linear model. Agatston scores were normalized using log2 after adding 1 to address zero values in the data. Linear regression was performed using the lm function in R and data was plotted using the data visualization package ggplot2 (39 ).
+ Open protocol
+ Expand
6

Determination of Copy Number Variation in Cancer DNA

Check if the same lab product or an alternative is used in the 5 most similar protocols
The array CGH data were analyzed with R statistical computing software (version 3.0.2; http://www.r‐project.org), and the hidden Markov model was applied, with the segmental maximum posteriori approach.18 We started by excluding the chromosome Y data and calculated the copy number ratio of cancer DNA to normal DNA. Copy number ratios were then categorized into six states with initial mean ratios of 0.50, 0.75, 1.00, 1.25, 1.50, and 2.00 with a standard deviation of 0.1. Two states, those with copy number ratios of 0.5 and 0.75, were defined as copy number loss, while those of 1.25, 1.50, and 2.00 states were defined as copy number gain. Sample no. 10 showed extremely rare copy number loss, and the estimates of two copy number states (initial values of 0.75 and 1.00) approached 1.00 (0.9783 and 0.9998, respectively). We defined these two states as representing a normal copy number for this sample. Correlations with clinicopathological features were calculated with Fisher’s exact test or the Wilcoxon rank sum test. Gene ontology analysis was carried out using the Database for Annotation, Visualization and Integrated Discovery (DAVID; http://david.abcc.ncifcrf.gov/).
+ Open protocol
+ Expand
7

Data Visualization and Statistical Analysis

Check if the same lab product or an alternative is used in the 5 most similar protocols
Data visualization and statistical analysis were performed using R statistical computing software (https://www.r-project.org/). Scatter plots were generated using ggplot2 package. Student’s t-test of the difference between two data sets were conducted using t.test function in R. For multiple comparisons, we performed ANOVA with Tukey’s test for post hoc analysis using aov and TukeyHSD function in R.
+ Open protocol
+ Expand
8

Assessing ADC Variations in MRI Test-Retest

Check if the same lab product or an alternative is used in the 5 most similar protocols
Statistical analysis was performed by using Excel (Office 2016, Microsoft) and R statistical computing software (version 3.0.3; http://www.r-project.org/). ADC variations in a test-retest scenario were assessed according to the Bland-Altman methodology [24 (link), 25 (link)]. Mean, relative difference, and standard deviation of the differences of two subsequent measurements on each machine are calculated and depicted in a Bland-Altman plot. The coefficient of variation (CoV) was estimated as CoV = standard deviation / mean (%). A Wilcoxon signed-rank test was performed to assess the variations in ADC values calculated at the MRI device and centrally. The significance level was adjusted according to the number of comparisons that were performed (Bonferroni correction, p < 0.007).
+ Open protocol
+ Expand
9

Fistula Length Predicts Abscess on MRI

Check if the same lab product or an alternative is used in the 5 most similar protocols
Continuous variables were represented as mean ± standard deviation or median and range and categorical variables as the percentage of the total number. The Fisher's exact test was performed to compare the differences between the categorical variables. Continuous variables were compared using Student's t-test. For all of the statistical analyses, a p value of <0.05 was considered statistically significant. The optimum threshold for total fistula length discriminating presence or absence of abscess on MRI was calculated based on receiver operating curve analysis (12 (link)). All statistical analyses were carried out using R statistical computing software (version 3.6.3, The R Foundation for Statistical Computing).
+ Open protocol
+ Expand
10

Predicting Prostate Cancer Outcomes

Check if the same lab product or an alternative is used in the 5 most similar protocols
Numerical variables were recorded and analysed as median [25th - 75th percentile] while categorical variables were expressed as frequencies and percentages. Comparisons between groups were based on the Mann-Whitney or Chi square tests. The predictive accuracy of testosterone was evaluated using Receiver Operating Characteristic (ROC) analysis and quantified in terms of Area Under the Curve (AUC) and corresponding 95% confidence interval (95% C.I.). The independent role of testosterone in predicting pathological outcomes at radical prostatectomy was assessed using multivariable logistic regression models; a bootstrap approach, based on 1999 bootstrap replications, was used to compare the percentage change in predictive accuracy (in terms of AUC) between nested logistic models.
Statistical analyses and modelling were performed with R statistical computing software (R Foundation for Statistical Computing, Vienna, Austria). P-values < 0.05 were considered statistically significant.
+ Open protocol
+ Expand

About PubCompare

Our mission is to provide scientists with the largest repository of trustworthy protocols and intelligent analytical tools, thereby offering them extensive information to design robust protocols aimed at minimizing the risk of failures.

We believe that the most crucial aspect is to grant scientists access to a wide range of reliable sources and new useful tools that surpass human capabilities.

However, we trust in allowing scientists to determine how to construct their own protocols based on this information, as they are the experts in their field.

Ready to get started?

Sign up for free.
Registration takes 20 seconds.
Available from any computer
No download required

Sign up now

Revolutionizing how scientists
search and build protocols!