Hi,

   I find the problem. Some of the numbers like "1357" are presented as
"1,357". After deleting the comma, everything is ok. Thank you for your
attention!

Miao

2012/8/22 jpm miao <miaojpm@gmail.com>

> Hi,
>
>    I am reading several .csv file of time series. Some values of the time
> series are unavailable. Some of the unavailable series are marked "NA", and
> some are just blank. The "NA" value can be read, but the blank cannot be
> read. Then I change the change the blank to "NA", but they can't be
> properly read.
>
>    When I check the difference between the two types of "NA", I find:
>
>    Those can be read are outputed as  "NA".
>    Those can't be read (which I change from the blank) are outputed as
> "<NA>".
>
>    Could anyone tell me how I can input the NA properly?
>
>    Thanks,
>
> Miao
>

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