使用magrittr T形三通%T>；%运算符创建错误

我试图创建两个图：一个是整个数据集，另一个是按“站点”分组因子分割的平均图

以下是源数据：

site.data <- structure(list(site = structure(c(1L, 1L, 1L, 1L,1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 3L), 
.Label = c("ALBEN", "ALDER", "AMERI"), class = "factor"),  
year = c(5L, 10L, 20L, 50L, 100L, 200L, 500L, 5L, 10L, 20L, 50L, 100L, 200L, 500L, 5L, 10L, 20L, 50L, 100L, 200L),
peak = c(101529.6, 117483.4, 132960.9, 153251.2, 168647.8, 184153.6, 204866.5, 6561.3, 7897.1, 9208.1, 10949.3,12287.6, 13650.2, 15493.6, 43656.5, 51475.3, 58854.4, 68233.3, 75135.9, 81908.3)),
.Names = c("site", "year","peak"), class = "data.frame", row.names = c(NA, -20L))  

但我得到了这个错误信息： as.vector（x，模式）中出错：无法将“环境”类型强制为“任意”类型的向量

现在，如果我用常规的magrittr管道操作符替换tee操作符，并注释掉第一个ggplot行，那么至少我得到了第二个ggplot，如下所示：

site.data %>%                                 
   #   ggplot(aes(year, peak, color = site)) + geom_line() + geom_point(size = 6)   %>%
group_by(site) %>%
summarize(mean = mean(peak)) %>%
ggplot(aes(site, mean, color = site)) + geom_point(size = 6)

---

有什么建议吗？谢谢

在这种情况下，操作顺序很重要。

%%

运算符的绑定比

+

更紧密。所以当你说

site.data %T>% ggplot(aes(year, peak, color = site)) + geom_line() 

那跟

( site.data %T>% ggplot(aes(year, peak, color = site)) ) + geom_line() 

这基本上是在做什么

site.data + geom_line()

返回与您得到的错误相同的错误。您需要将所有ggplot图层添加/修改显式分组到一个代码块中。试一试

site.data %T>%     
{print(ggplot(., aes(year, peak, color = site)) + geom_line() + geom_point(size = 6))}  %>%
group_by(site) %>%  
summarize(mean = mean(peak)) %>%
{ggplot(., aes(site, mean, color = site)) + geom_point(size = 6)}

---

有关R中的操作顺序，请参见

？语法
帮助页。
site.data %T>%     
{print(ggplot(., aes(year, peak, color = site)) + geom_line() + geom_point(size = 6))}  %>%
group_by(site) %>%  
summarize(mean = mean(peak)) %>%
{ggplot(., aes(site, mean, color = site)) + geom_point(size = 6)}