按条件在 R 中随机子集行

Question

我正在尝试根据列值之一将 dataframe 子集化为一个较小的值，数据帧如下 head()

Experiment SRA_Sample              Sample_Name Grupo_analisis body_site
1  SRX567480  SRS626942 GTEX-111CU-0226-SM-5GZXC              1   Thyroid
2  SRX615964  SRS644174 GTEX-111FC-1026-SM-5GZX1              1   Thyroid
3  SRX563960  SRS625636 GTEX-111VG-0526-SM-5N9BW              3   Thyroid
4  SRX564185  SRS625665 GTEX-111YS-0726-SM-5GZY8              1   Thyroid
5  SRX559141  SRS624025 GTEX-1122O-0226-SM-5N9DA              1   Thyroid
6  SRX561718  SRS625313 GTEX-1128S-0126-SM-5H12S              1   Thyroid
         molecular_data_type    sex Group ShortName
1 Allele-Specific Expression   male   NIT 111CU_NIT
2              RNA Seq (NGS)   male   NIT 111FC_NIT
3              RNA Seq (NGS)   male   ELI 111VG_ELI
4 Allele-Specific Expression   male   NIT 111YS_NIT
5              RNA Seq (NGS) female   NIT 1122O_NIT
6 Allele-Specific Expression female   NIT 1128S_NIT

有3组ELI，NIT y SCI，我想随机select每个class的10个样本。 我正在努力：

> set.seed(12)
> targets10<- filter(targets, targets$Group== ("NIT", "ELI", "SFI")) %>% sample_n(., 10)

or

>targets10<-filter(targets, targets$Group== "NIT","ELI","SFI") %>% sample_n(., 10)

给我以下错误： (~targets$Group == "NIT") & ~"ELI": 操作只能用于数字、逻辑或复杂类型

有人可以帮我吗？？？

比你提前这么多

Answer 1

尝试像这样重新格式化您的代码：

dplyr解决方案：

targets10 <- targets %>% 
  filter(Group %in% c("NIT", "ELI", "SFI")) %>% 
  sample_n(., 10)

base R解决方案：

targets10 <- subset(survey, Group %in% c("NIT", "ELI", "SFI"))
targets10 <- sample_n(targets10, 10)

编辑：

要从每组中抽取 10 个样本，您只需添加group_by ：

targets10 <- targets %>% 
  filter(Group %in% c("NIT", "ELI", "SFI")) %>% 
  group_by(Group) %>% 
  sample_n(., 10)