如何向量化长度-频率计算？

Question

At the moment I have a quite long code with a for loop calculating the frequency of the various lengths at different maturities of a dataset, I would like to vectorize the code/find a more elegant solution, however so far I've not been able to work out how to do that. The frequency calculation is a relatively simple one: (count of occurances of a specific length at a certain maturity/total number of females or males)*100

Example data:

   Species Sex Maturity    Length
1     HAK   M        1         7
2     HAK   M        2         24
3     HAK   F        2         10
4     HAK   M        3         25
5     HAK   F        5         25
6     HAK   F        4         12

Code that I'm currently using:

reps <- seq(min(Length), max(Length), by = 1)
m1      <- m2 <- m3 <- m4 <- m5 <- rep(NA, length(reps))
f1      <- f2 <- f3 <- f4 <- f5 <- rep(NA, length(reps))
# Makes vectors for each maturity stage for both sexes 
# same length as the reps vector filled with NA for the loop:
# Loop:

for (i in 1:length(reps)) # repeats for each value of the x axis

{

        m1[i]<- length(Length[Length == reps[i] & Sex == "M" & Maturity == 1])/total.m*100
        m2[i]<- length(Length[Length == reps[i] & Sex == "M" & Maturity == 2])/total.m*100
        m3[i]<- length(Length[Length == reps[i] & Sex == "M" & Maturity == 3])/total.m*100
        m4[i]<- length(Length[Length == reps[i] & Sex == "M" & Maturity == 4])/total.m*100
        m5[i]<- length(Length[Length == reps[i] & Sex == "M" & Maturity == 5])/total.m*100
        f1[i]<- length(Length[Length == reps[i] & Sex == "F" & Maturity == 1])/total.f*100
        f2[i]<- length(Length[Length == reps[i] & Sex == "F" & Maturity == 2])/total.f*100
        f3[i]<- length(Length[Length == reps[i] & Sex == "F" & Maturity == 3])/total.f*100
        f4[i]<- length(Length[Length == reps[i] & Sex == "F" & Maturity == 4])/total.f*100
        f5[i]<- length(Length[Length == reps[i] & Sex == "F" & Maturity == 5])/total.f*100

}
#Stitching together the output of the  loop.
males_all<-rbind(m1, m2, m3, m4, m5)
females_all<-rbind(f1, f2, f3, f4, f5)

This is the output I usually get from the loop:

 mat       X8       X9       X10       X11      X12       X14       X15
1  m1 0.104712 0.104712 0.6282723 1.3612565 1.884817 0.1047120 0.2094241
2  m2 0.000000 0.000000 0.3141361 0.8376963 2.198953 2.4083770 1.3612565
3  m3 0.000000 0.000000 0.0000000 0.0000000 0.104712 0.2094241 0.1047120
4  m4 0.000000 0.000000 0.0000000 0.0000000 0.000000 0.0000000 0.0000000
5  m5 0.000000 0.000000 0.0000000 0.0000000 0.000000 0.0000000 0.2094241

The columns after mat are the lengths, for the sake of brevity I've not included all of them, they would go up to 30 or so. The females_all looks the same, just with f1, f2 etc. in the mat column.

Answer 1

Near as I can tell, this is what you want:

library(dplyr)
counts = count(df, Sex, Maturity, Length)
totals = count(df, Sex, name = "total")

counts = counts %>% left_join(totals) %>%
  mutate(prop = n / total)
# # Joining, by = "Sex"
# # A tibble: 6 x 6
#   Sex   Maturity Length     n total  prop
#   <fct>    <int>  <int> <int> <int> <dbl>
# 1 F            2     10     1     3 0.333
# 2 F            4     12     1     3 0.333
# 3 F            5     25     1     3 0.333
# 4 M            1      7     1     3 0.333
# 5 M            2     24     1     3 0.333
# 6 M            3     25     1     3 0.333

counts %>% select(Sex, Maturity, Length, prop) %>%
  tidyr::spread(key = Length, value = prop, fill = 0)
# # A tibble: 6 x 7
#   Sex   Maturity   `7`  `10`  `12`  `24`  `25`
#   <fct>    <int> <dbl> <dbl> <dbl> <dbl> <dbl>
# 1 F            2 0     0.333 0     0     0    
# 2 F            4 0     0     0.333 0     0    
# 3 F            5 0     0     0     0     0.333
# 4 M            1 0.333 0     0     0     0    
# 5 M            2 0     0     0     0.333 0    
# 6 M            3 0     0     0     0     0.333

Using this data:

df = read.table(text = "   Species Sex Maturity    Length
1     HAK   M        1         7
2     HAK   M        2         24
3     HAK   F        2         10
4     HAK   M        3         25
5     HAK   F        5         25
6     HAK   F        4         12", header = T)