R中的波浪线Tilde_in

这篇具有很好参考价值的文章主要介绍了R中的波浪线Tilde_in_R。希望对大家有所帮助。如果存在错误或未考虑完全的地方，请大家不吝赐教，您也可以点击"举报违法"按钮提交疑问。

Tilde in R ~

Tilde symbol l is used within formulas of statistical models, as mainly this symbol is used to define the relationship between the dependent variable and the independent variables in the statistical model formula in the R programming language. The left side of the tilde symbol specifies the target variable (dependent variable or outcome) and the right side of the tilde specifies the predictor variable(independent variables). (Source: https://www.geeksforgeeks.org/use-of-tilde-in-r/)

Below source: https://bookdown.org/danieljcarter/r4steph/two-sample-t-test.html

Two-sample t-test

We can also conduct a two-sample t-test to determine if the mean population birthweight in boys is the same as the mean population birthweight in girls. The syntax here is slightly different as it uses R’s formula interface. A formula is indicated by the presence of a tilde (~), and the tilde is shorthand for ‘estimate’. So the formula in the code chunk below says: estimate birthweight from sex. This is slightly counter-intuitive for the t-test but will make more sense when applied more generally under a regression framework later on.

We use the var.test() command to conduct an F test to assess whether the equality of variance assumption holds.


```r
#--- Run the two-sample t-test
bab9 %$% t.test(bweight ~ sex, var.equal = T)

## 
##  Two Sample t-test
## 
## data:  bweight by sex
## t = 3, df = 600, p-value = 0.001
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
##   66.6 267.7
## sample estimates:
##   mean in group male mean in group female 
##                 3211                 3044

Bonferroni correction for multiple tests

Source: https://book.phylolab.net/binf8441/lab7.html
R中的波浪线Tilde_in_R,r语言,开发语言


```r
numtest = 4
pvalue = 1:numtest
for(i in 1:numtest){
    pvalue[i] = t.test(data[,i+1] ~ data[,1])$p.value
}

print("the Bonferroni adjusted pvalues")
pvalue*numtest

We estimate the four columns based on the first column, 0 or 1 group. 是按照第一列分成的两组。文章来源地址https://www.toymoban.com/news/detail-835997.html

> t.test(data[,i+1] ~ data[,1])

	Welch Two Sample t-test

data:  data[, i + 1] by data[, 1]
t = -2.9682, df = 17.128, p-value = 0.008566
alternative hypothesis: true difference in means between group 0 and group 1 is not equal to 0
95 percent confidence interval:
 -2.6167353 -0.4430667
sample estimates:
mean in group 0 mean in group 1 
      0.3970631       1.9269641

到了这里，关于R中的波浪线Tilde_in_R的文章就介绍完了。如果您还想了解更多内容，请在右上角搜索TOY模板网以前的文章或继续浏览下面的相关文章，希望大家以后多多支持TOY模板网！