我想读取从雅虎获得的数据的价格和计算回报,传递无法读取数据的符号。代码
library("TTR")
source("util.r")
symbols =
for (sym in c("CSI","XCSIX","IGI")) {
cat("\nreading data for",sym,"\n")
tryCatch(
{
stk = getYahooData(sym, start = 20000101, end = 20200101, freq = "daily")
ndays = length(index(stk))
logret = ((log(stk$Close) - lag(log(stk$Close)))) [2:ndays]
print(summary(logret))},
error = cat("could not read data for ",sym))
}
不起作用,提供输出
reading data for CSI
could not read data for CSI Index Close
Min. :2000-01-04 00:00:00 Min. :-0.1640284
1st Qu.:2003-10-27 06:00:00 1st Qu.:-0.0028756
Median :2007-08-16 12:00:00 Median : 0.0000000
Mean :2007-08-16 05:37:08 Mean : 0.0003147
3rd Qu.:2011-06-05 06:00:00 3rd Qu.: 0.0037004
Max. :2015-03-26 00:00:00 Max. : 0.2523210
reading data for XCSIX
could not read data for XCSIXError in tryCatchOne(expr, names, parentenv, handlers[[1L]]) :
attempt to apply non-function
Calls: tryCatch -> tryCatchList -> tryCatchOne
In addition: Warning message:
In file(file, "rt") : cannot open: HTTP status was '404 Not Found'
Execution halted
如何正确使用tryCatch?
答案 0 :(得分:2)
# This may work
library("TTR")
source("util.r")
symbols =
for (sym in c("CSI","XCSIX","IGI")) {
cat("\nreading data for",sym,"\n")
tryCatch(
{
stk = getYahooData(sym, start = 20000101, end = 20200101, freq = "daily")
ndays = length(index(stk))
logret = ((log(stk$Close) - lag(log(stk$Close)))) [2:ndays]
print(summary(logret))},
error=function(err) {
cat("Data doesn't exist for company:", sym, "and the error is", conditionMessage(err), "\n")
})
}
答案 1 :(得分:1)
如果其他所有方法都失败了,请按照?tryCatch
中的示例操作。 tryCatch(..., error = function(e) e)
。 error
是一个函数,而不是表达式。
library("TTR")
for (sym in c("CSI","XCSIX","IGI")) {
cat("\nreading data for",sym,"\n")
tryCatch(getYahooData(sym, start=20000101, end=20200101),
error = function(e) cat("could not read data for ",sym))
}