具有缺失值的因子的变量平均值

Question

我正在使用一个大数据集来按因子计算变量的均值。示例简单数据集如下所示。

 +------+-----+------+--------+------+-------+------+------+
| year | mon | site | region |  rf  | avg 1 | avg2 | avg3 |
+------+-----+------+--------+------+-------+------+------+
| 2000 | jan | A    | high   | 28.2 |       |      |      |
| 2000 | feb | A    | high   | 26.6 |       |      |      |
| 2000 | mar | A    | high   | 30.3 |       |      |      |
| 2000 | apr | A    | high   | 33.2 |       |      |      |
| 2000 | may | A    | high   |      |       |      |      |
| 2000 | jun | A    | high   | 28.3 |       |      |      |
| 2000 | jul | A    | high   | 28.6 |       |      |      |
| 2000 | aug | A    | high   | 28.9 |       |      |      |
| 2000 | sep | A    | high   | 28.1 |       |      |      |
| 2000 | oct | A    | high   | 28.8 |       |      |      |
| 2000 | nov | A    | high   | 31.6 |       |      |      |
| 2000 | dec | A    | high   | 26.9 |       |      |      |
| 2001 | jan | A    | high   | 28.6 |       |      |      |
| 2001 | feb | A    | high   | 29.6 |       |      |      |
| 2002 | jan | B    | mid    | 21.4 |       |      |      |
| 2002 | feb | B    | mid    | 24.5 |       |      |      |
| 2002 | mar | B    | mid    | 24.2 |       |      |      |
+------+-----+------+--------+------+-------+------+------+

但是主变量 (rf) 有一些缺失值。但我想计算删除缺失值的方法 (avg 1, avg2 avg3)。可以使用以下输入代码访问我的数据集。

structure(list(year = c(2000L, 2000L, 2000L, 2000L, 2000L, 2000L, 
2000L, 2000L, 2000L, 2000L, 2000L, 2000L, 2001L, 2001L, 2002L, 
2002L, 2002L), mon = structure(c(5L, 4L, 8L, 1L, 9L, 7L, 6L, 
2L, 12L, 11L, 10L, 3L, 5L, 4L, 5L, 4L, 8L), .Label = c("apr", 
"aug", "dec", "feb", "jan", "jul", "jun", "mar", "may", "nov", 
"oct", "sep"), class = "factor"), site = structure(c(1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L), .Label = c("A", 
"B"), class = "factor"), region = structure(c(1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L), .Label = c("high", 
"mid"), class = "factor"), rf = c(28.2, 26.6, 30.3, 33.2, NA, 
28.3, 28.6, 28.9, 28.1, 28.8, 31.6, 26.9, 28.6, 29.6, 21.4, 24.5, 
24.2), avg_rf_site_allyears = c(NA, NA, NA, NA, NA, NA, NA, NA, 
NA, NA, NA, NA, NA, NA, NA, NA, NA), avg_mon_rf_all_site = c(NA, 
NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA
), avg_rf_year_ele = c(NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, 
NA, NA, NA, NA, NA, NA, NA)), .Names = c("year", "mon", "site", 
"region", "rf", "avg_rf_site_allyears", "avg_mon_rf_all_site", 
"avg_rf_year_ele"), class = "data.frame", row.names = c(NA, -17L
))

avg 1 是所有年份的平均降雨量（我有 15 年的月度）。

avg 2 是所有地点所有年份的平均月降雨量

avg 3 是各地区年平均降雨量

我正在使用以下代码，但这些代码不适用于具有缺失值的网站。

平均 1

df$avg.1<- with(df,ave(rf, site)) # mean rf by sites across all years. This does not calculate values for sites if it has got even one missing value.

平均 2

df$avg2<- with(df,ave(rf, mon))#this works in this example but not with my    big dataset. When I run with my dataset, it gives all NAs.

如果有人也能告诉我这个问题的潜在原因，那就太好了。

avg 3 - 我需要按年按地区计算均值。但是找不到解决方法。

如能提供上述任何帮助，我们将不胜感激。

Answer 1

我们可以在ave中指定FUN参数。默认情况下，即没有指定，它给出 mean 和 na.rm=FALSE。因此，使用 FUN，可以使用 min、max 等任何其他函数。

df$avg.1 <- with(df, ave(rf, site, 
        FUN= function(x) mean(x, na.rm=TRUE)))

'avg.2'.

同样如此

对于第三种情况

df$avg.3 <- with(df, ave(rf, region, year, 
        FUN= function(x) mean(x, na.rm=TRUE))

如果我们使用 dplyr

library(dplyr)
df %>%
  group_by(site) %>% 
  mutate(avg.1 = mean(rf, na.rm=TRUE)) %>% 
  group_by(mon) %>% 
  mutate(avg.2 = mean(rf, na.rm=TRUE)) %>% 
  group_by(region, year) %>%
  mutate(avg.3= mean(rf, na.rm=TRUE))

具有缺失值的因子的变量平均值

Mean of variables by factors with missing values

average

r

factors

missing-data