抑制警告消息并在r中继续循环

更新 ahmohamed的解决方案

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lapplyquote_数据为.null，因此您可以像在中按列表_清理qoute_数据一样清理列表。首先，您需要检查下载过程中是否发生错误。您可以在getPrice函数中完成此操作

getPrice<-function(ticker){
    ticker<-paste(ticker,'ss',sep='.')
    price <- try(get.hist.quote(instrument=ticker,start='2013-01-01',end='2015-02-14',quiet=TRUE))
    if(class(price) == "try-error") #if error occurred
        price <- NULL
    return(price)
}

注意：我没有使用get_hist_quote函数的经验，但是如果每次调用它时它都会下载数据，那么您应该为列表中的所有股票代码调用getPrice函数一次，并将数据存储在一个变量中供以后使用。比如说,

screenStock<-function(list_in){

quote_data <- lapply(list_in, getPrice)
filtered_quote_data <- quote_data[-which(lapply(quote_data,is.null))]

for (i in 1:(length(filtered_quote_data)-1)){
    s1<-filtered_quote_data[i]
         for (j in 2:length(filtered_quote_data)){
                s2<-filtered_quote_data[j]

# Continue your code. 

---

谢谢你，这比我的原始代码有了很大的改进。但是它仍然不能避免一些错误。屏幕停止在列表中第一个元素之后的。我已经知道HSlist中的000002将在GetPrice中返回错误。这不是编程问题。出现错误是因为url不存在。即使在浏览器中粘贴也会出现错误。你是对的。该列表包含一些不再存在的代码，即，这是一个“脏”列表。有没有办法确定和清理清单？也就是说，识别“不存在错误类型”，然后从列表中删除相应的ticker。脏ticker在上述代码中给出，其中applyquote_数据为.null，因此您可以像我们在中通过列表清理qoute_数据一样清理列表

getPrice<-function(ticker){
    ticker<-paste(ticker,'ss',sep='.')
    tryCatch({price<-get.hist.quote(instrument=ticker,start='2013-01-01',end='2015-02-14',quiet=TRUE)})
    return(price)
}

tts<-function(s1,s2){
    require(fUnitRoots)
    a<-getPrice(s1)[,4]
    b<-getPrice(s2)[,4]
    if (length(a)==length(b)){
    fit<-lm(a~b+0)
    result<-suppressWarnings(adfTest(fit$residuals,type='nc'))
    return(result)
    }
    else return(NULL)
}

screenStock<-function(list_in){

            result<-data.frame()
            n<-0
            for (i in 1:(length(list_in)-1)){
                s1<-getPrice(list_in[i])
                for (j in 2:length(list_in)){
                    s2<-getPrice(list_in[j])
                    adf_T<-tts(s1,s2)
                    if (!is.null(adf_T) && adf_T@test$p.value==0.01){
                        n<-n+1
                        result[n,1]<-list_in[i]
                        result[n,2]<-list_in[j]    
                        result[n,3]<-adf_T@test$statistic}                        
                    }
                }
            return(result) 
        }

> screenStock(HSlist)
download error, retrying ...
download error, retrying ...
download error, retrying ...
download error, retrying ...
Error in get.hist.quote(instrument = ticker, start = "2013-01-01", end = "2015-02-14",  : 
  cannot open URL 'http://chart.yahoo.com/table.csv?s=c("000001", "000002", "000004", "000005", "000006", "000007", "000008", "000009", "000010", "000011", "000012", "000014", "000016", "000017", "000018", "000019", "000020", "000021", "000022", "000023", "000024", "000025", "000026", "000027", "000028", "000029", "000030", "000031", "000032", "000033", "000034", "000035", "000036", "000037", "000039", "000040", "000042", "000043", "000045", "000046", "000048", "000049", "000050", "000055", "000056", "000058", "000059", "000060", "000061", "000062", 
"000063", "000065", "000066", "000068", "000655", "000656", "000659", "000661", "000662", "000663", "000665", "000666", "000667", "000668", "000669", "000671", "000673", "000676", "000677", "000678", "000679", "000680", "000682", "000683", "000685", "000686", "000687", "000690", "000691", "000692", "000695", "000697", "000698", "000700", "000701", "000702", "000703", "000705", "000707", "000708", "000709", "000710", "000711", "0007
In addition: Warning messages:
1: In download.file(url, destfile, method = method, quiet = quiet) :
  cannot open: HTTP status was '0 (nil)'
2: In download.file(url, destfile, method = method, quiet = quiet) :
  cannot open: HTTP status was '0 (nil)'
3: In download.file(url, destfile, method = method, quiet = quiet) :
  cannot open: HTTP status was '0 (nil)'
4: In download.file(url, destfile, method = method, quiet = quiet) :
  cannot open: HTTP status was '0 (nil)'
5: In download.file(url, destfile, method = method, quiet = quiet) :
  cannot open: HTTP status was '0 (nil)'

getPrice<-function(ticker){
    ticker<-paste(ticker,'ss',sep='.')
    price <- try(get.hist.quote(instrument=ticker,start='2013-01-01',end='2015-02-14',quiet=TRUE))
    if(class(price) == "try-error") #if error occurred
        price <- NULL
    return(price)
}

if (!is.null(s1) && !is.null(s2) && (length(a)==length(b))){
# Do your test    
}

screenStock<-function(list_in){

quote_data <- lapply(list_in, getPrice)
filtered_quote_data <- quote_data[-which(lapply(quote_data,is.null))]

for (i in 1:(length(filtered_quote_data)-1)){
    s1<-filtered_quote_data[i]
         for (j in 2:length(filtered_quote_data)){
                s2<-filtered_quote_data[j]

# Continue your code.