使用嵌套 group_by 时 dplyr 出错

Question

我正在尝试使用 dplyr 执行多项操作，但我卡住了，我不知道我做错了什么。

我的 60760 观察数据框的前十五行如下所示：

df <-structure(list(dem_sect = structure(c(4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 1L),
.Label = c("AB", "EP", "FE", "MF", "PA"), class = "factor"), 
area = c(1181.16, 1181.16, 2190.28, 2190.28, 956.08, 2190.28, 1181.16, 2190.28, 956.08, 2190.28, 2190.28, 1181.16, 2190.28, 956.08, 921.47), 
peso_kg = c(0.184, 0.674, 0.1, 0.152, 0.21, 0.104, 4.31, 0.048, 0.242, 0.724, 0.126, 1.13, 0.13, 0.048, 0.075),
sector = c("MFa", "MFa", "MFb", "MFb", "MFc", "MFb", "MFa", "MFb", "MFc", "MFb", "MFb", "MFa", "MFb", "MFc", "ABb")), 
row.names = c(NA, 15L), class = data.frame")

这是我正在使用的代码

test <- df %>% 
group_by(sector) %>%
summarise(md_area= mean (area),
          md_peso= mean (peso_kg),
          se_loc= sqrt(var(peso_kg))/sqrt(length (peso_kg)),
          cv_loc= sd(peso_kg)/ mean (peso_kg)*100) %>%
group_by(dem_sect) %>%
mutate(sum_sect = sum(SEloc * CVloc)))

我尝试使用 mutate(sum_sect=sum(mean(area) * mean(peso_kg)) 而不是 mutate(sum_sect = sum(SEloc * CVloc)，但在这两种情况下我都收到以下错误：

Error in group_by(): ! Must group by variables found in .data. x Column dem_sect is not found.

我尝试了几种方法但都没有成功。我不知道我做错了什么。任何提示都将非常受欢迎。提前致谢。

Answer 1

如果您想对 dem_sect 的每个唯一值进行一次观察，则：

test <- df %>%
    group_by(sector) %>%
    mutate(
        md_area = mean(area),
        md_peso = mean(peso_kg),
        se_loc = sqrt(var(peso_kg))/sqrt(length(peso_kg)),
        cv_loc = sd(peso_kg)/mean(peso_kg)*100
    ) %>%
    ungroup() %>%
    group_by(dem_sect) %>%
    summarize(sum_sect = sum(SEloc * CVloc)))

我觉得SEloc和CVloc不存在，应该是se_loc和cv_loc吧？

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