[R] How to import and create time series data frames in an efficient way?

[Bert Gunter]

So you've made no attempt at all to do this for yourself?!

That suggests to me that you need to spend time with some R tutorials.

Also, please post in plain text on this plain text list. HTML can get
mangled, as it may have here.

-- Bert
"The trouble with having an open mind is that people keep coming along and
sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )


On Thu, Nov 14, 2019 at 4:11 PM Nhan La <lathanhnhan using gmail.com> wrote:

> I have many separate data files in csv format for a lot of daily stock
> prices. Over a few years there are hundreds of those data files, whose
> names are the dates of data record.
>
> In each file there are variables of ticker (or stock trading code), date,
> open price, high price, low price, close price, and trading volume. For
> example, inside a data file named 20150128.txt it looks like this:
>
> FB,20150128,1.075,1.075,0.97,0.97,725221
> AAPL,20150128,2.24,2.24,2.2,2.24,63682
> AMZN,20150128,0.4,0.415,0.4,0.415,194900
> NFLX,20150128,50.19,50.21,50.19,50.19,761845
> GOOGL,20150128,1.62,1.645,1.59,1.63,684835 ...................and many
> more..................
>
> In case it's relevant, the number of stocks in these files are not
> necessarily the same (so there will be missing data). I need to import and
> create 5 separate time series data frames from those files, one each for
> Open, High, Low, Close and Volume. In each data frame, rows are indexed by
> date, and columns by ticker. For example, the data frame Open may look like
> this:
>
> DATE,FB,AAPL,AMZN,NFLX,GOOGL,... 20150128,1.5,2.2,0.4,5.1,1.6,...
> 20150129,NA,2.3,0.5,5.2,1.7,... ...
>
> What will be an efficient way to do that? I've used the following codes to
> read the files into a list of data frames but don't know what to do next
> from here.
>
> files = list.files(pattern="*.txt") mydata = lapply(files,
> read.csv,head=FALSE)
>
> Thanks,
>
> Nathan
>
> Disclaimer: In case it's relevant, this question is also posted on
> stackoverflow.
>
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>
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