抽样分布和表格总和

Question

我做了一些实验，每个实验都导致了颜色的显现。 由于我不能做更多的实验，我想要samplesize=30，看看我可以获得1000次采样的频率表（颜色）。产生的频率表应该是1000频率表的总和。

我认为有关串联表如下，并尝试agregate，但没有奏效：

mydata=structure(list(Date = structure(c(11L, 1L, 9L, 9L, 10L, 1L, 2L, 
3L, 4L, 4L, 5L, 5L, 5L, 5L, 5L, 6L, 7L, 4L, 4L, 4L, 6L, 6L, 11L, 
5L, 4L, 7L, 10L, 6L, 6L, 2L, 5L, 7L, 11L, 1L, 9L, 11L, 11L, 11L, 
1L, 1L), .Label = c("01/02/2016", "02/02/2016", "03/02/2016", 
"08/02/2016", "10/02/2016", "11/02/2016", "16/02/2016", "22/02/2016", 
"26/01/2016", "27/01/2016", "28/01/2016"), class = "factor"), 
    Color = structure(c(30L, 33L, 11L, 1L, 18L, 18L, 11L, 
    16L, 19L, 19L, 22L, 1L, 18L, 18L, 13L, 14L, 13L, 18L, 24L, 
    24L, 11L, 24L, 2L, 33L, 25L, 1L, 30L, 5L, 24L, 18L, 13L, 
    35L, 19L, 19L, 18L, 23L, 19L, 8L, 19L, 14L), .Label = c("ARD", 
    "ARP", "BBB", "BIE", "CFX", "CHR", "DDD", "DOO", "EAU", "ELY", 
    "EPI", "ETR", "GEN", "GER", "GGG", "GIS", "ISE", "JUV", "LER", 
    "LES", "LON", "LYR", "MON", "NER", "NGY", "NOJ", "NYO", "ORI", 
    "PEO", "RAY", "RRR", "RSI", "SEI", "SEP", "VIL", "XQU", "YYY", 
    "ZYZ"), class = "factor"), Categorie = structure(c(1L, 1L, 
    1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
    1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
    1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = c("1", "1,2", "1,2,3", 
    "1,3", "2", "2,3", "3", "4", "5"), class = "factor"), Portion_Longueur = c(3L, 
    4L, 1L, 1L, 2L, 4L, 5L, 6L, 7L, 7L, 8L, 8L, 9L, 8L, 8L, 9L, 
    11L, 7L, 7L, 7L, 9L, 8L, 3L, 8L, 7L, 11L, 2L, 9L, 8L, 5L, 
    8L, 12L, 3L, 4L, 1L, 3L, 3L, 3L, 4L, 5L)), .Names = c("Date", 
"Color", "Categorie", "Portion_Longueur"), row.names = c(NA, 
40L), class = "data.frame") 

for (i in 1:1000) { 
mysamp= sample(mydata$Color,size=30) 
x=data.frame(table(mysamp)) 

if (i==1) w=x 
else w <- c(w, x) 

} 
aggregate(w$Freq, by=list(Color=w$mysamp), FUN=sum) 

例如，对于3个采样，for (i in 1:3)我希望有金额如下：

但我没有总和，而是我有：

Color x 
1 ARD 2 
2 ARP 1 
3 BBB 0 
4 BIE 0 
5 CFX 0 
6 CHR 0 
7 DDD 0 
8 DOO 1 
9 EAU 0 
10 ELY 0 
11 EPI 3 
12 ETR 0 
13 GEN 2 
14 GER 2 
15 GGG 0 
16 GIS 1 
17 ISE 0 
18 JUV 4 
19 LER 5 
20 LES 0 
21 LON 0 
22 LYR 1 
23 MON 1 
24 NER 2 
25 NGY 1 
26 NOJ 0 
27 NYO 0 
28 ORI 0 
29 PEO 0 
30 RAY 1 
31 RRR 0 
32 RSI 0 
33 SEI 2 
34 SEP 0 
35 VIL 1 
36 XQU 0 
37 YYY 0 
38 ZYZ 0 

如何做到这一点？

非常感谢

Answer 1

你for循环是什么导致你的问题。你最终创建一个有点难以执行计算的大列表（查看names(w)查看我的意思）。更好的数据结构可以使计算更容易：

x = NULL #initialize 
for (i in 1:1000) { 
    mysamp = sample(mydata$Color,size=30) #sample 
    mysamp = data.frame(table(mysamp)) #frequency 
    x = rbind(x, mysamp) #bind to x 
} 
aggregate(Freq~mysamp, data = x, FUN = sum) #perform calculation 

请注意，该循环运行速度比循环慢一点。这是因为rbind()函数。看到这个post。也许有人会提出更有效的解决方案。