R中的Foreach循环：错误任务2失败-“找不到对象”

Question

我正在尝试在循环内的循环上运行带有%dopar% 的foreach 循环，但出现以下错误：Error in { : task 2 failed - "object 'price_floor' not found"。这是代码（错误似乎发生在foreach (n = 2:nrow(timesaleDat_id)) %dopar%...行之后）：

numCores <- parallel::detectCores() - 1

myCluster <- parallel::makeCluster(numCores, type = "PSOCK")

print(myCluster) # Returns "socket cluster with 7 nodes on host ‘localhost’"

doParallel::registerDoParallel(cl = myCluster)

foreach::getDoParRegistered() # Returns "TRUE"

foreach::getDoParWorkers() # Returns "7"

tStopLoss <- seq(0.00, 0.03, by = 0.01)

for (l in 1:length(tStopLoss)) {
        for (m in 1:nrow(bids_entity_id)) {
          bidTStamp <- bids_entity_id$tStamp[m]
          timesaleDat_id <- timesaleDat_time[timesaleDat_time$tStamp >= bidTStamp, ]
          if (nrow(timesaleDat_id) >= 2) {
            foreach (n = 2:nrow(timesaleDat_id)) %dopar% {
              if (n == 2) {
                if (timesaleDat_id$price[n] >= timesaleDat_id$price[n - 1] * (1 - tStopLoss[l])) {
                  price_floor <- timesaleDat_id$price[n - 1]
                  price_init <- timesaleDat_id$price[n - 1]
                  time_init <- timesaleDat_id$tStamp[n - 1]
                  if (timesaleDat_id$price[n] > price_floor) {
                    price_floor <- timesaleDat_id$price[n]
                  }
                } else if (timesaleDat_id$price[n] < timesaleDat_id$price[n - 1] * (1 - tStopLoss[l])) {
                  bids_entity_id$priceChange[m] <- timesaleDat_id$price[n] - timesaleDat_id$price[n - 1]
                  bids_entity_id$priceChangePct[m] <- (timesaleDat_id$price[n] - timesaleDat_id$price[n - 1]) / 
                    timesaleDat_id$price[n - 1]
                  bids_entity_id$timeChange[m] <- timesaleDat_id$tStamp[n] - timesaleDat_id$tStamp[n - 1]
                  break
                }
              } else if (n > 2) {
                if (timesaleDat_id$price[n] >= price_floor * (1 - tStopLoss[l])) {
                  if (timesaleDat_id$price[n] > price_floor) {
                    price_floor <- timesaleDat_id$price[n]
                  }
                } else if (timesaleDat_id$price[n] < price_floor * (1 - tStopLoss[l])) {
                  bids_entity_id$priceChange[m] <- timesaleDat_id$price[n] - price_init
                  bids_entity_id$priceChangePct[m] <- (timesaleDat_id$price[n] - price_init) / price_init
                  bids_entity_id$timeChange[m] <- timesaleDat_id$tStamp[n] - time_init
                  break
                }
              }
            }
          }
        }
      }

bids_entity_id 是具有以下结构的数据帧，其中length(unique(bids_entity_id$tick)) == 1、length(unique(bids_entity_id$entity)) == 1 和length(unique(bids_entity_id$bid_ask)) == 1：

'data.frame':   5988 obs. of  11 variables:
 $ tStamp        : num  1624455002264 1624455010287 1624455011778 1624455012780 1624455013749 ...
 $ tick          : chr  "ATOS" "ATOS" "ATOS" "ATOS" ...
 $ entity        : chr  "MEMX" "MEMX" "MEMX" "MEMX" ...
 $ bid_ask       : chr  "bid" "bid" "bid" "bid" ...
 $ price         : num  6.5 6.57 6.59 6.61 6.63 6.66 6.65 6.65 6.65 6.65 ...
 $ size          : int  100 600 500 400 100 300 800 400 400 400 ...
 $ x             : int  30596619 30610012 30611053 30612308 30613618 30614531 30615664 30615664 30615664 30615664 ...
 $ diffFromPrice : chr  NA NA NA NA ...
 $ priceChange   : logi  NA NA NA NA NA NA ...
 $ priceChangePct: logi  NA NA NA NA NA NA ...
 $ timeChange    : logi  NA NA NA NA NA NA ...

timesaleDat_time 是具有以下结构的数据帧，其中length(unique(timesaleDat_time$tick)) == 1:

'data.frame':   48540 obs. of  6 variables:
 $ seq   : int  595 596 597 598 599 600 601 602 603 604 ...
 $ tick  : chr  "ATOS" "ATOS" "ATOS" "ATOS" ...
 $ tStamp: num  1624455000313 1624455000315 1624455000315 1624455000315 1624455000315 ...
 $ price : num  6.6 6.61 6.6 6.59 6.59 6.58 6.58 6.57 6.57 6.57 ...
 $ size  : int  309468 100 100 400 129 165 100 176 400 100 ...
 $ index : int  24833 24834 24835 24836 24837 24838 24839 24840 24841 24842 ...

Answer 1

price_floor 不会在 else if (n > 2) 之后的第一个 if 之前分配。