r - 对速度波束和方向扇区进行分类

Question

我有一个速度矢量和另一个方向矢量。

我想按 [0-2,2-4,4-6....] 的波束对我的速度进行分类，并为每个波束按扇区返回统计摘要。例如:

**光束 [2-4] 米/秒

sector        Mean          Sigma 
345-15:        3.12         0.49
15-45:         3.16         0.52
45-75:         3.10         0.45
...

目前，通过使用 cut 我获得了:

vel_bins: (0,5] (0,5] (0,5] (0,5] (0,5] (0,5]

(5,10] (5,10] (5,10] (5,10] (10,15] (10,15] (10,15]

(10,15] (10,15] (10,15] (10,15]

dir_bins: (67.5,90] (67.5,90] (67.5,90] (67.5,90] (67.5,90]

(67.5,90] (67.5,90] (67.5,90] (67.5,90] (45,67.5] (45,67.5]

(45,67.5] (67.5,90] (67.5,90] (45,67.5]

如果我使用 table(vel_bins,dir_bins) 我得到:

> vel_dir_table
           vel_bins
dir_bins    (0,5] (5,10] (10,15] (15,20] (20,25] (25,30]

  (0,22.5]   1956   1122     196       3       0       0

  (22.5,45]  2435   2628     618      62       2       0

  (45,67.5]  2800   7196    6744     422       5       0

  (67.5,90]  2970   5806    3422      16       0       0

  (90,112]   2908   2156     381       0       0       0

  (112,135]  2031   1221      55       0       0       0

  (135,158]  1990   1271     172       8       0       0

  (158,180]  1966   1397     274      10       1       0

  (180,202]  2272   1509     623      57      13       3

  (202,225]  2423   2611    2022     407      26       9

  (225,248]  3605   4963    1782     451      64      16

  (248,270]  2889   6480    2804     289      21       9

  (270,292]  2113   3610    2117     126      11       6

  (292,315]  1811   2268     996     102      14       0

  (315,338]  2022   1900    1044      69      28       0

  (338,360]  1769   1150     258       4       0       0

但是我不知道怎么跟进。如果有人愿意帮助将非常感激! 谢谢!

Answer 1

希望你能看懂我的代码:

# max values, velocity v and position x
max.v <- 12
max.x <- 100

# number of segments
l.v <- 5
l.x <- 4

# random data
data <- data.frame(x=runif(1000, 0, max.x + 3), v=runif(1000, 0, max.v + 3))

dir.v <- seq(0, max.v, length=l.v)
dir.x <- seq(0, max.x, length=l.x)

# create empty matrix of lists
m <- matrix(list(NA), l.x, l.v)

# sort x and v
pos.x <- floor(data$x/max.x * (l.x-1)) + 1
pos.v <- floor(data$v/max.v * (l.v-1)) + 1

# if >l.x then it is put in the last one
pos.x[pos.x>=l.x] <- l.x
pos.v[pos.v>=l.v] <- l.v

# sort
for(i in 1:length(data$v)){
  m[[pos.x[i], pos.v[i]]] <- append(m[[pos.x[i], pos.v[i]]], data$v[i])
}

# write to file
fileConn<-file("output.txt", open="w")
for(i in 1:l.v){
  write(paste("v", "x", "mean(v)", "\t\tsd(v)", sep="\t"), file=fileConn, append=TRUE)
  for(j in 1:l.x){
    write(paste(dir.v[i], round(dir.x[j],1), mean(m[[j,i]], na.rm = TRUE), sd(m[[j,i]], na.rm=TRUE), sep="\t"), file=fileConn, append=TRUE)
  }
  write("\n", file=fileConn, append=TRUE)
}
close(fileConn)

希望对您有所帮助。