将 R 中的粒子包应用于海洋速度答案

【问题标题】：Applying particles package in R to ocean velocity将 R 中的粒子包应用于海洋速度
【发布时间】：2021-06-12 13:40:22
【问题描述】：

我正在尝试将 R“粒子”包中的示例应用于海洋速度数据（动能）。示例数据如下：

ke1<-c(0.394610137,0.203202814,0.12364389,0.069784589,0.048573241,0.043057494,0.03826768,0.034176417,0.032129359,0.03122394
)
ke2<-c(0.094138406,0.169889584,0.086677499,0.070593894,0.049883354,0.042339094,0.038856283,0.037967827,0.036562074,0.037240546
)
ke3<-c(0.054365572,0.096576959,0.10304369,0.061354585,0.053624138,0.042112421,0.040727202,0.039870735,0.042947762,0.043291345
)
ke4<-c(0.030527802,0.075901449,0.08003746,0.068991989,0.048506431,0.044592839,0.04071483,0.042985249,0.042403288,0.044974718
)
ke5<-c(0.021374704,0.047852065,0.070487022,0.059393879,0.051129311,0.042866949,0.040003292,0.040003441,0.044107087,0.04578279
)
ke<-cbind(ke1,ke2,ke3,ke4,ke5)

library(particles)
library(tidygraph)

kee<-as.numeric(unlist(ke))

sim <- create_empty(1000) %>% 
  simulate(alpha_decay = 0, setup = aquarium_genesis(vel_max = 1)) %>%
  wield(reset_force, xvel = 0, yvel = 0) %>% 
  wield(field_force, angle = kee, vel = kee , xlim = c(-5, 5), ylim = c(-5, 5)) %>% 
  evolve(1000, record)

我已将粒子包中的脚本应用于示例数据，但出现以下错误。

Error in matrix(vel, ncol = ncol(angle), nrow = nrow(angle)) : 
  non-numeric matrix extent

感谢评论，我成功解决了非数字矩阵的问题。

接下来增加速度数据量(row = 233, col = 154)，出现如下错误。

Error: cannot allocate vector of size 152.6 Mb

我尝试使用 gc() 检查我使用的内存量。

 gc()
            used   (Mb) gc trigger   (Mb)  max used   (Mb)
Ncells   2765657   84.5    4718054  144.0   4718054  144.0
Vcells 311435640 2376.1  480298947 3664.4 439560179 3353.6

memory.limit 是 4000（上限）。可以说是电脑内存造成的吗？

【问题讨论】：

我建议您提出一个新问题，因为您的编辑内容有所不同。但是，是的，我认为可以公平地说你没有足够的内存。要么删除未使用的对象rm(...)，获得更多内存的机器，或者看看你是否有办法以更高的内存效率来处理它

标签： r particles ocean

【解决方案1】：

问题在于kee 是向量而不是矩阵。所以ncol 和nrow 返回为NULL 而不是实际数字。这是一个较小的可重现示例，说明它失败的原因：

v1 = 1:3
v2 = 2:4

mat = cbind(v1, v2)
non_mat = as.numeric(unlist(mat))

## works!
matrix(mat, ncol(mat), ncol(mat))
#>      [,1] [,2]
#> [1,]    1    3
#> [2,]    2    2

## doesn't work!!
matrix(non_mat, ncol = ncol(non_mat), nrow = nrow(non_mat))
#> Error in matrix(non_mat, ncol = ncol(non_mat), nrow = nrow(non_mat)): non-numeric matrix extent

## it doesn't work because we return ncol = NULL and nrow = NULL
### the matrix needs an actual number!
ncol(non_mat)
#> NULL
nrow(non_mat)
#> NULL

要解决此问题，请在第二个 wield() 调用中使用 ke 而不是 kee。

【讨论】：