R 如何逐行变异并将第一个'n'值替换为0

我正在try 构建一个测量跟踪器表单.我想根据各行的Quantity值将0填充到每行的"Measures"列中.(对于数量=2，前2个测量值=0，行的其余部分=NA).(对于数量=4，所有测量值=0).

我想知道如何改变这些行，并在正确索引的位置用适当数量的0替换，如下所示:

 Feature Tool MIN MAX Quantity Measurement_1 Measurement_2 Measurement_3 Measurement_4
1       a    m 0.5 1.0        2             0             0            NA            NA
2       b    n 0.4 1.2        4             0             0             0             0

生成数据帧的示例代码如下所示:

#sample data
A1 <- data.frame(Feature = c("a","b"), Tool = c("m","n"), MIN = c(0.5,0.4), MAX = c(1.0,1.2), Quantity = c(2,4))  

# Create empty data frame of NA
df <- data.frame(matrix(NA,    
                          nrow = 1,
                          ncol = max(A1$Quantity)))

#create list of sequential measurements based on maximum quantity of measurements
M <- c(sprintf("Measurement_%01d", seq(1,max(A1$Quantity)))) 

#set column names to these measurements
colnames(df) <- M  

#combine sample data with measurements
new_dat <- cbind(A1, df)  

我第一次try 做到这一点是这样的:

new_dat %>% rowwise() %>% mutate(new_dat[,6:new_dat$Quantity] <- 0)

但很明显我漏掉了一些东西.

谢谢!