distinct(test,Species,.keep_all = T)#.keep_all意思是把所有列都保存下来mutate,数据框新增一列mutate(test, new = Sepal.Length...select(filter(iris,Sepal.Width>3), Sepal.Length,Sepal.Width), Sepal.Length)专题三:条件和循环一....条件语句if(){ } *只有if没有else,那么条件是FALSE时就什么都不做i = -1if (i0) print('up')#理解下面代码if(!...tumor");k1ifelse(k1,"tumor","normal")k2 = str_detect(samples,"normal");k2ifelse(k2,"normal","tumor")多个条件...,z = 30:27);test#返回值是列表,对列表中的每个元素(向量)求均值(试试方差var,分位数quantile)lapply(test,mean)lapply(test,fivenum)#3.