r-Mutate语句无法启用图形

Question

通过一个关于太阳黑子数据的tidyverse时间序列示例，当我试图以10年为增量绘制图时，得到了以下错误消息，似乎无法识别步骤1中创建的新日期变量，不知道这是否是格式问题
错误：mutate()列decade出现问题。idecade = f(date)。x下标越界

感谢的任何帮助

# libraries
library(datasets)
library(tidyverse)
library(tsibble)
library(ggplot)
# Tidy the data
tidy_ts <- sunspots %>%  
as_tsibble() %>%        # Convert to timeseries tibble
mutate(                 # Create new variables
year = year(index),   # Create a year column
month = month(index)  # Create a month column
) %>%
select(                 # Select, reorder, rename vars
date = index,         # Rename "index" to "date"
year,                 # Use "year" as second variable
month,                # Use "month" as third variable
spots = value         # Rename "value" as "spots"
) %>%
print()                 # Show data
view(tidy_ts)
# Graph the tidy data by decade
tidy_ts %>%
index_by(                            # By decade
decade = ~ floor_date(tidy_ts$date, years(10))
) %>%
summarise(mean_s = mean(spots)) %>%  # Mean for decade
ggplot(aes(decade, mean_s)) +        # Plot means
geom_point() +                       # Scatterplot
geom_smooth() +                      # Smoother
ylab("Sunspots: Mean by Decade")     # Label

Answer 1

尝试替换：

index_by(                            # By decade
decade = ~ floor_date(tidy_ts$date, years(10))
)

带有：

index_by(decade = floor(year/10)*10)