新列中的计算

Question

我测量了两种土壤类型的化合物在两天内的排放量。

现在我想计算一下每天丙酮和乙醛对每一种土壤类型总排放量的贡献。我想在我的数据中建立一个新的列，例如计算(丙酮排放/总排放量) *100。

有什么想法吗？

这是数据

df <- structure(list(soil_type = c("SOC<10", "SOC<10", "SOC<10", "SOC<10", 
"SOC<10", "SOC<10", "SOC>10", "SOC>10", "SOC>10", "SOC>10", "SOC>10", 
"SOC>10"), compound = c("Acetaldehyde", "Acetaldehyde", "Acetone", 
"Acetone", "Total emission", "Total emission", "Acetaldehyde", "Acetaldehyde", 
"Acetone", "Acetone", "Total emission", "Total emission"), day = c(0L, 
4L, 0L, 4L, 0L, 4L, 0L, 4L, 0L, 4L, 0L, 4L), mean = c(0.03, 0.07, 
0.02, 0.04, 0.06, 0.11, 0.01, 0.04, 0.05, 0.07, 0.08, 0.13)), row.names = c(NA, 
-12L), groups = structure(list(soil_type = c("SOC<10", "SOC<10", 
"SOC<10", "SOC>10", "SOC>10", "SOC>10"), compound = c("Acetaldehyde", 
"Acetone", "Total emission", "Acetaldehyde", "Acetone", "Total emission"
), .rows = structure(list(1:2, 3:4, 5:6, 7:8, 9:10, 11:12), ptype = integer(0), class = c("vctrs_list_of", 
"vctrs_vctr", "list"))), row.names = c(NA, -6L), class = c("tbl_df", 
"tbl", "data.frame"), .drop = TRUE), class = c("grouped_df", 
"tbl_df", "tbl", "data.frame"))

Answer 1

对于每一个soil_type和day，你可以计算出丙酮发射/总排放量*100的比率。

library(dplyr)

df %>%
  group_by(soil_type, day) %>%
  mutate(ratio = mean[match('Acetone', compound)]/
                 mean[match('Total emission', compound)] * 100) %>%
  ungroup -> result

result

#   soil_type compound         day  mean ratio
#   <chr>     <chr>          <int> <dbl> <dbl>
# 1 SOC<10    Acetaldehyde       0  0.03  33.3
# 2 SOC<10    Acetaldehyde       4  0.07  36.4
# 3 SOC<10    Acetone            0  0.02  33.3
# 4 SOC<10    Acetone            4  0.04  36.4
# 5 SOC<10    Total emission     0  0.06  33.3
# 6 SOC<10    Total emission     4  0.11  36.4
# 7 SOC>10    Acetaldehyde       0  0.01  62.5
# 8 SOC>10    Acetaldehyde       4  0.04  53.8
# 9 SOC>10    Acetone            0  0.05  62.5
#10 SOC>10    Acetone            4  0.07  53.8
#11 SOC>10    Total emission     0  0.08  62.5
#12 SOC>10    Total emission     4  0.13  53.8