[R] a question on sqldf's handling of missing value and factor

[Gabor Grothendieck]

On Wed, Mar 2, 2011 at 10:17 AM, xin wei <xinwei at stat.psu.edu> wrote:
> I am sorry for posting the wrong source file. the correct source file is as
> follows:
> a       b       c
> aa              23
> aaa     34.6
> aaaa            77.8
>
> They are tab delimited but somehow could not be displayed correctly in
> browser.

The problem is that you are using empty fields to represent missing
values but SQLite regarded them as zero length character fields.  See
FAQ 14 on  the sqldf home page for a solution:
http://code.google.com/p/sqldf/#14._How_does_one_read_files_where_numeric_NAs_are_represented_as

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