[R] "Missing value representation in Excel before extraction to R with RODBC"
Prof Brian Ripley
ripley at stats.ox.ac.uk
Mon Jan 9 09:36:06 CET 2006
On Mon, 9 Jan 2006, Petr Pikal wrote:
> I believe it has something to do with the column identification
> decision. When R decides what is in a column it uses only some values
> from the beginning of a file.
Not R, Excel. Excel tells ODBC what the column types are.
> I do not use RODBC as read.delim("clipboard", ...) is usually more
> convenient but probably there is a way how to tell RODBC what is in
> the column instead of let R decide from the top of the file.
Using as.is=TRUE stops RODBC doing any conversion.
> But I may be completely mistaken.
> On 6 Jan 2006 at 20:47, Fredrik Lundgren wrote:
> From: "Fredrik Lundgren" <fredrik.bg.lundgren at bredband.net>
> To: "R-help" <r-help at stat.math.ethz.ch>
> Date sent: Fri, 6 Jan 2006 20:47:29 +0100
> Subject: [R] "Missing value representation in Excel before extraction to R
> with RODBC"
>> Dear list,
>> How should missing values be expressed in Excel before extraction to R
>> via RODBC. I'm bewildered. Sometimes the representation with NA in
>> Excel appears to work and shows up in R as <NA> but sometimes the use
>> of NA in Excel changes the whole vector to NA's. Blank or nothing or
>> NA as representation for missing values in Excel with dateformat gives
>> NA's of the whole vector in R but with general format in Excel gives
>> blanks for missing values in R. How should I represent missing values
>> in Excel?
>> Best wishes and thanks for any help
>> Fredrik Lundgren
Brian D. Ripley, ripley at stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
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