在R中的汇总预测表中按组加入残差

时间:2018-12-17 09:18:07

标签: r dplyr data.table lapply

可复制的示例

df=structure(list(group = c(1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 
                            2L, 2L, 2L), year = c(1973L, 1974L, 1975L, 1976L, 1977L, 1978L, 
                                                  1973L, 1974L, 1975L, 1976L, 1977L, 1978L), Jan = c(9007L, 7750L, 
                                                                                                     8162L, 7717L, 7792L, 7836L, 9007L, 7750L, 8162L, 7717L, 7792L, 
                                                                                                     7836L), Feb = c(8106L, 6981L, 7306L, 7461L, 6957L, 6892L, 8106L, 
                                                                                                                     6981L, 7306L, 7461L, 6957L, 6892L), Mar = c(8928L, 8038L, 8124L, 
                                                                                                                                                                 7767L, 7726L, 7791L, 8928L, 8038L, 8124L, 7767L, 7726L, 7791L
                                                                                                                     ), Apr = c(9137L, 8422L, 7870L, 7925L, 8106L, 8192L, 9137L, 8422L, 
                                                                                                                                7870L, 7925L, 8106L, 8192L), May = c(10017L, 8714L, 9387L, 8623L, 
                                                                                                                                                                     8890L, 9115L, 10017L, 8714L, 9387L, 8623L, 8890L, 9115L), Jun = c(10826L, 
                                                                                                                                                                                                                                       9512L, 9556L, 8945L, 9299L, 9434L, 10826L, 9512L, 9556L, 8945L, 
                                                                                                                                                                                                                                       9299L, 9434L), Jul = c(11317L, 10120L, 10093L, 10078L, 10625L, 
                                                                                                                                                                                                                                                              10484L, 11317L, 10120L, 10093L, 10078L, 10625L, 10484L), Aug = c(10744L, 
                                                                                                                                                                                                                                                                                                                               9823L, 9620L, 9179L, 9302L, 9827L, 10744L, 9823L, 9620L, 9179L, 
                                                                                                                                                                                                                                                                                                                               9302L, 9827L), Sep = c(9713L, 8743L, 8285L, 8037L, 8314L, 9110L, 
                                                                                                                                                                                                                                                                                                                                                      9713L, 8743L, 8285L, 8037L, 8314L, 9110L), Oct = c(9938L, 9129L, 
                                                                                                                                                                                                                                                                                                                                                                                                         8466L, 8488L, 8850L, 9070L, 9938L, 9129L, 8466L, 8488L, 8850L, 
                                                                                                                                                                                                                                                                                                                                                                                                         9070L), Nov = c(9161L, 8710L, 8160L, 7874L, 8265L, 8633L, 9161L, 
                                                                                                                                                                                                                                                                                                                                                                                                                         8710L, 8160L, 7874L, 8265L, 8633L), Dec = c(8927L, 8680L, 8034L, 
                                                                                                                                                                                                                                                                                                                                                                                                                                                                     8647L, 8796L, 9240L, 8927L, 8680L, 8034L, 8647L, 8796L, 9240L
                                                                                                                                                                                                                                                                                                                                                                                                                         )), .Names = c("group", "year", "Jan", "Feb", "Mar", "Apr", "May", 
                                                                                                                                                                                                                                                                                                                                                                                                                                        "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"), class = "data.frame", row.names = c(NA, 
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              -12L))

Perforcat按组分组

library(forecast)
ld <- split(df[, -1], df$group)
ld <- lapply(ld, function(x) {ts(c(t(x[,-1])), start = min(x[,1]), frequency = 12)})

lts <- lapply(ld, ets, model = "ZZZ")

结果

$`1`
         Point Forecast     Lo 80     Hi 80    Lo 95     Hi 95
Jan 1979       8397.497  8022.399  8772.595 7823.834  8971.160
Feb 1979       7599.221  7162.825  8035.616 6931.812  8266.630
Mar 1979       8396.595  7906.510  8886.679 7647.075  9146.115
Apr 1979       8646.510  8108.063  9184.957 7823.026  9469.994

从1979年开始,它是预测值,我想要得到残差的结果 1973-1978。(初始值)

res <- lapply(lts, residuals)

和结果

$`1`
            Jan        Feb        Mar        Apr        May        Jun        Jul        Aug        Sep        Oct        Nov
1973  497.69233   99.50607   64.44947  -15.20925   77.85009  390.89045 -277.67369   26.92614   72.42590  -85.69894 -338.10035

以此类推

问题 1.如何将残差结果加入汇总表。例如这样的事情 enter image description here

  1. 问题: 对于1979年及以后,我们看到了预测值,但是对于1973-1978年,在列点预测中,我们看到了残差。 当然,理想情况下,不会得到太多残差,而应得到原始值和预测值。 所以我不知道如何将1973-1978年的初始数据加入汇总表原始值中 df[df$year == 1973,],但全年如何... 然后从原始值中减去残差并得到预测值(也许我使任务复杂化了,但是否则我不知道如何获得所需的输出) enter image description here

不需要更改名称point forecastlo80hi80,我会记住,对于初始值,它们表示残差,原始值和预测值。

是否可以使用dplyr或data.table解决方案?

# Tidy-up the splits
ld <- lapply(ld, function(x) {
  x %>%
    gather(key, value, -year) %>%
    unite(date, year, key, sep = "-") %>%
    mutate(date = paste0(date, "-01")) %>%
    mutate(date = as.Date(date, format = "%Y-%b-%d"))    
})

结果

$`1`
   date value
1  <NA>  9007
2  <NA>  7750
3  <NA>  8162
4  <NA>  7717
5  <NA>  7792
6  <NA>  7836
7  <NA>  8106
8  <NA>  6981
9  <NA>  7306
10 <NA>  7461
11 <NA>  6957
12 <NA>  6892


ld=dput()
ld <- lapply(ld, function(x) {
  yr <- lubridate::year(min(x$date))
  mth <- lubridate::month(min(x$date))
  timetk::tk_ts(data = x, select = value, frequency = 12,
                start = c(yr, mth))
})

错误

 Error in x$date : $ operator is invalid for atomic vectors 

edit3

> lts_all <- lapply(names(lts), function(x, lts) {
+   output_fit <- lts[[x]][["res_fit_tbl"]] %>%
+     mutate(group = x)
+   output_fcst <- lts[[x]][["res_fcst_tbl"]] %>%
+     mutate(group = x)
+   
+   return(list(output_fit=output_fit, output_fcst=output_fcst))
+ }, lts)
> lts_all
[[1]]
[[1]]$output_fit
# A tibble: 72 x 6
   date       value residuals CI95_upper CI95_lower group
   <date>     <dbl>     <dbl>      <dbl>      <dbl> <chr>
 1 1973-01-01  8509     498         9083       7936 value
 2 1973-02-01  8006      99.5       8580       7433 value
 3 1973-03-01  8864      64.4       9437       8290 value
 4 1973-04-01  9152    - 15.2       9726       8579 value
 5 1973-05-01  9939      77.9      10513       9365 value
 6 1973-06-01 10435     391        11009       9861 value
 7 1973-07-01 11595    -278        12168      11021 value
 8 1973-08-01 10717      26.9      11291      10143 value
 9 1973-09-01  9641      72.4      10214       9067 value
10 1973-10-01 10024    - 85.7      10597       9450 value
# ... with 62 more rows

1 个答案:

答案 0 :(得分:1)

df开始,这是一个完整的解决方案,可重复的示例:

# load libraries
load_pkgs <- c("forecast", "zoo", "timetk", "tidyverse") 
sapply(load_pkgs, function(x) suppressPackageStartupMessages(library(x, character.only = T)))

第1步:预处理

# perform split by group
ld <- split(df[, -1], df$group)

# Tidy-up the splits
ld <- lapply(ld, function(x) {
  x %>%
    gather(key, value, -year) %>%
    unite(date, year, key, sep = "-") %>%
    mutate(date = paste0(date, "-01")) %>%
    mutate(date = as.Date(date, format = "%Y-%b-%d"))    
})

dput首先提示:

structure(list(date = structure(c(1096, 1461, 1826, 2191, 2557, 
                                  2922, 1127, 1492, 1857, 2222, 2588, 2953, 1155, 1520, 1885, 2251, 
                                  2616, 2981, 1186, 1551, 1916, 2282, 2647, 3012, 1216, 1581, 1946, 
                                  2312, 2677, 3042, 1247, 1612, 1977, 2343, 2708, 3073, 1277, 1642, 
                                  2007, 2373, 2738, 3103, 1308, 1673, 2038, 2404, 2769, 3134, 1339, 
                                  1704, 2069, 2435, 2800, 3165, 1369, 1734, 2099, 2465, 2830, 3195, 
                                  1400, 1765, 2130, 2496, 2861, 3226, 1430, 1795, 2160, 2526, 2891, 
                                  3256), class = "Date"), value = c(9007L, 7750L, 8162L, 7717L, 
                                                                    7792L, 7836L, 8106L, 6981L, 7306L, 7461L, 6957L, 6892L, 8928L, 
                                                                    8038L, 8124L, 7767L, 7726L, 7791L, 9137L, 8422L, 7870L, 7925L, 
                                                                    8106L, 8192L, 10017L, 8714L, 9387L, 8623L, 8890L, 9115L, 10826L, 
                                                                    9512L, 9556L, 8945L, 9299L, 9434L, 11317L, 10120L, 10093L, 10078L, 
                                                                    10625L, 10484L, 10744L, 9823L, 9620L, 9179L, 9302L, 9827L, 9713L, 
                                                                    8743L, 8285L, 8037L, 8314L, 9110L, 9938L, 9129L, 8466L, 8488L, 
                                                                    8850L, 9070L, 9161L, 8710L, 8160L, 7874L, 8265L, 8633L, 8927L, 
                                                                    8680L, 8034L, 8647L, 8796L, 9240L)), class = "data.frame", row.names = c(NA, 
                                                                                                                                             -72L))

然后

# Transform time series to ts objects
ld <- lapply(ld, function(x) {
  yr <- lubridate::year(min(x$date))
  mth <- lubridate::month(min(x$date))
  timetk::tk_ts(data = x, select = value, frequency = 12,
                start = c(yr, mth))
})

dput首先提示:

structure(c(9007L, 8106L, 8928L, 9137L, 10017L, 10826L, 11317L, 
            10744L, 9713L, 9938L, 9161L, 8927L, 7750L, 6981L, 8038L, 8422L, 
            8714L, 9512L, 10120L, 9823L, 8743L, 9129L, 8710L, 8680L, 8162L, 
            7306L, 8124L, 7870L, 9387L, 9556L, 10093L, 9620L, 8285L, 8466L, 
            8160L, 8034L, 7717L, 7461L, 7767L, 7925L, 8623L, 8945L, 10078L, 
            9179L, 8037L, 8488L, 7874L, 8647L, 7792L, 6957L, 7726L, 8106L, 
            8890L, 9299L, 10625L, 9302L, 8314L, 8850L, 8265L, 8796L, 7836L, 
            6892L, 7791L, 8192L, 9115L, 9434L, 10484L, 9827L, 9110L, 9070L, 
            8633L, 9240L), .Dim = c(72L, 1L), .Dimnames = list(NULL, "value"), index = structure(c(94694400, 
                                                                                                   97372800, 99792000, 102470400, 105062400, 107740800, 110332800, 
                                                                                                   113011200, 115689600, 118281600, 120960000, 123552000, 126230400, 
                                                                                                   128908800, 131328000, 134006400, 136598400, 139276800, 141868800, 
                                                                                                   144547200, 147225600, 149817600, 152496000, 155088000, 157766400, 
                                                                                                   160444800, 162864000, 165542400, 168134400, 170812800, 173404800, 
                                                                                                   176083200, 178761600, 181353600, 184032000, 186624000, 189302400, 
                                                                                                   191980800, 194486400, 197164800, 199756800, 202435200, 205027200, 
                                                                                                   207705600, 210384000, 212976000, 215654400, 218246400, 220924800, 
                                                                                                   223603200, 226022400, 228700800, 231292800, 233971200, 236563200, 
                                                                                                   239241600, 241920000, 244512000, 247190400, 249782400, 252460800, 
                                                                                                   255139200, 257558400, 260236800, 262828800, 265507200, 268099200, 
                                                                                                   270777600, 273456000, 276048000, 278726400, 281318400), tzone = "UTC", tclass = "Date"), .indexCLASS = "Date", tclass = "Date", .indexTZ = "UTC", tzone = "UTC", class = "ts", .Tsp = c(1973, 
                                                                                                                                                                                                                                                                                           1978.91666666667, 12))

第2步:使用ets

进行培训和预测

您需要一个帮助功能来将输出转换为数据框:

# helping function
make_df <- function(ts_obj) {

  ts_df <- timetk::tk_tbl(preserve_index = TRUE, ts_obj) %>%
    mutate(index = zoo::as.Date(x = .$index, frac = 0)) %>% 
    dplyr::rename(date = index)

  return(ts_df)
}

以下函数训练ets并预测接下来的12个月;然后,准备具有拟合值和预测值的表:

lts <- lapply(ld, function(ts_obj) {
# train ets model and get fitted results
res_model <- ets(ts_obj, model = "ZZZ")
res_fit <- ts(as.numeric(res_model$fitted), start = start(ts_obj), frequency = 12)

# add extra metrics you may be interested in
model <- res_model[["method"]]
mse <- res_model[["mse"]]

# get forecasts for the next 12 months
res_fct <- forecast(res_model, h = 12)
res_fcst <- ts(res_fct$mean, start = end(ts_obj) + 1/12, frequency = 12)

# transform results to tbl
# for fitted output we keep the residuals and the 95% CI
res_fit_tbl <- make_df(res_fit) %>%
  mutate(residuals = as.numeric(res_model[["residuals"]])) %>%
  mutate(CI95_upper = value + 1.96*sqrt(res_model$sigma2), 
         CI95_lower = value - 1.96*sqrt(res_model$sigma2))
# the forecast output does not have residuals
res_fcst_tbl <- make_df(res_fcst)

return(list(res_fit_tbl = res_fit_tbl, res_fcst_tbl = res_fcst_tbl, model = model, mse = mse)) # don't forget to pass the extra metrics as output
})

第3步:将不同组的拟合结果和预测结果汇总在一起

# add groups back + other metrics of interest
lts_all <- lapply(names(lts), function(x, lts) {
  output_fit <- lts[[x]][["res_fit_tbl"]] %>%
    mutate(group = x,
           model = lts[[x]][["model"]],
           mse = lts[[x]][["mse"]])
  output_fcst <- lts[[x]][["res_fcst_tbl"]] %>%
    mutate(group = x)

  return(list(output_fit=output_fit, output_fcst=output_fcst))
  }, lts)

示例输出:

> lts_all[[1]][["output_fit"]]
# A tibble: 72 x 6
   date        value residuals CI95_upper CI95_lower group
   <date>      <dbl>     <dbl>      <dbl>      <dbl> <chr>
 1 1973-01-01  8509.     498.       9083.      7936. 1    
 2 1973-02-01  8006.      99.5      8580.      7433. 1    
 3 1973-03-01  8864.      64.4      9437.      8290. 1    
 4 1973-04-01  9152.     -15.2      9726.      8579. 1    
 5 1973-05-01  9939.      77.9     10513.      9365. 1    
 6 1973-06-01 10435.     391.      11009.      9861. 1    
 7 1973-07-01 11595.    -278.      12168.     11021. 1    
 8 1973-08-01 10717.      26.9     11291.     10143. 1    
 9 1973-09-01  9641.      72.4     10214.      9067. 1    
10 1973-10-01 10024.     -85.7     10597.      9450. 1    
# ... with 62 more rows

> lts_all[[2]][["output_fit"]]
# A tibble: 72 x 6
   date        value residuals CI95_upper CI95_lower group
   <date>      <dbl>     <dbl>      <dbl>      <dbl> <chr>
 1 1973-01-01  8509.     498.       9083.      7936. 2    
 2 1973-02-01  8006.      99.5      8580.      7433. 2    
 3 1973-03-01  8864.      64.4      9437.      8290. 2    
 4 1973-04-01  9152.     -15.2      9726.      8579. 2    
 5 1973-05-01  9939.      77.9     10513.      9365. 2    
 6 1973-06-01 10435.     391.      11009.      9861. 2    
 7 1973-07-01 11595.    -278.      12168.     11021. 2    
 8 1973-08-01 10717.      26.9     11291.     10143. 2    
 9 1973-09-01  9641.      72.4     10214.      9067. 2    
10 1973-10-01 10024.     -85.7     10597.      9450. 2    
# ... with 62 more rows

然后

# bring together the fitted respectively forecasting results
output_fit_all <- lapply(lts_all, function(x) x[[1]])
output_fit_all <- bind_rows(output_fit_all)

output_fcst_all <- lapply(lts_all, function(x) x[[2]])
output_fcst_all <- bind_rows(output_fcst_all)