R语言：基于多列二进制数据添加新列的实现问题

无法在R的数据框中添加新列，需求是新增一列，标记所有病毒检测列中是否存在数值"1"（阳性），该列将用于后续概率计算。

样本数据 #

Filovirus (MOD) PCR   :    Phlebo (Sanchez-Seco) PCR
0                          0         
0                          1            
0                          0            
0                          0        
0                          0         
0                          0        
0                          0       
0                          0         
0                          0        
0                          0   


species code  forest site
<fctr>  <dbl> <fctr>
SM      1     UMNP-mangabey
SM      1     UMNP-mangabey
RC      9     UMNP-hondohondoc
BWC     9     UMNP-hondohondod
BWC     9     UMNP-hondohondod
BWC     9     UMNP-hondohondod
BWC     9     UMNP-hondohondod
BWC     9     UMNP-hondohondod
BWC     9     UMNP-hondohondod
BWC     9     UMNP-hondohondod

尝试过的代码（未成功） #

tmp=which(data==1,arr.ind=T)    
tmp=tmp[order(tmp[,"row"]),]
c("positive","negative")[tmp[,"col"]] -> data$new

数据的dput结构 #

structure(list(`Filovirus (MOD) PCR` = c("0", "0", "0", "0", 
"0", "0", "0", "0", "0", "0"), `Filovirus (A) PCR` = c("0", "0", 
"0", "0", "0", "0", "0", "0", "0", "0"), `Filovirus (B) PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Filo C PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Filovirus (D) PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Coronavirus   (Quan) PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Coronavirus (Watanabe) PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Paramyxo  (Tong)  PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Flavivirus Moureau PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Flavivirus  Sanchez-seco PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Arena Lozano 1 PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Retrovirus Courgnard PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Simian Foamy Goldberg (Pol) PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Simian Foamy Goldberg (LTR Region) PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Influenza (Anthony) PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Influenza (Liang) PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Rhabdo (CII) PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Enterovirus CII I PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Enterovirus CII-II PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Alphav   (Sanchez-Seco) PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Lyssavirus (Vasquez-Moron) PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Seadornavirus (CII) PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Hantavirus (Raboni) PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Hantavirus (Klempa) PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Nipah (Wacharapleusadee) PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Henipa (Feldman) PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Bunya S (Briese) PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Bunya L (Briese) PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), `Phlebo (Sanchez-Seco) PCR` = c("0", 
"0", "0", "0", "0", "0", "0", "0", "0", "0"), species = structure(c(3L, 
5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L), .Label = c("SM", "SY", "BWC", 
"YB", "RC"), class = "factor"), code = c(2, 5, 5, 5, 5, 5, 5, 
5, 5, 5), forestsite = structure(c(3L, 14L, 14L, 14L, 14L, 14L, 
14L, 14L, 14L, 14L), .Label = c("Magombera1", "Magombera2", "NDUFR", 
"Ndundulu1", "Ndundulu2", "Ndundulu3", "Nyumbanitu", "UMNP-campsite3", 
"UMNP-hondohondoa", "UMNP-hondohondob", "UMNP-hondohondoc", "UMNP-hondohondod", 
"UMNP-hondohondoe", "UMNP-HQ", "MamaGoti", "UMNP-mangabey", "UMNP-njokamoni", 
"UMNP-Sanje1", "UMNP-Sanje2", "UMNP-Sanje3", "Sonjo", "SonjoRoad"
), class = "factor")), row.names = c(NA, -10L), class = c("tbl_df", 
"tbl", "data.frame"))

可行解决方案 #

问题根源 #

原代码失败的原因有两个：

1. 病毒检测列存储为字符型（"0"），而非数值型，data==1无法匹配到任何值；
2. 逻辑错误：原代码试图按列索引生成标记，但实际需要行级判断——判断每行是否存在至少一个"1"。

方法1：Base R实现（无需额外包） #

# 1. 提取所有病毒检测列（列名包含PCR）
pcr_cols <- grep("PCR", names(data), value = TRUE)

# 2. 可选：将字符型的检测列转为数值型，方便后续计算
data[pcr_cols] <- lapply(data[pcr_cols], as.numeric)

# 3. 逐行判断是否存在阳性（1），生成标记列
data$positive_status <- ifelse(
  rowSums(data[pcr_cols] == 1, na.rm = TRUE) > 0,
  "positive",
  "negative"
)

方法2：tidyverse/dplyr实现（更简洁） #

如果习惯使用tidyverse语法：

library(dplyr)

data <- data %>%
  # 转换PCR列为数值型（可选）
  mutate(across(contains("PCR"), as.numeric)) %>%
  # 生成阳性标记列：任意PCR列等于1则标记为positive
  mutate(positive_status = case_when(
    if_any(contains("PCR"), ~ .x == 1) ~ "positive",
    TRUE ~ "negative"
  ))

验证结果 #

运行代码后，positive_status列会标记每行是否存在病毒阳性结果，可直接用于后续概率计算。

内容的提问来源于stack exchange，提问作者Marnee Roundtree