R help - Aug 2010 - Why do the results of paste() depend on how the argument (data.frame) is constructed?

Hi,

The following two 'df's should be the same, although their
constructions are different. But the results of paste() are different.
I don't see this is explained in ?paste. Could you help me understand
why it is like this?
> df=data.frame(X=c(1, 2, 3), Y=c(4, 5, 6))
> df
  X Y
1 1 4
2 2 5
3 3 6
> paste(df)
[1] "c(1, 2, 3)" "c(4, 5, 6)"
> df=data.frame(X=1:3, Y=4:6)
> df
  X Y
1 1 4
2 2 5
3 3 6
> paste(df)
[1] "1:3" "4:6"
>

-- 
Tom

On 08/01/2010 08:48 PM, thmsfuller066 at gmail.com
wrote:
> Hi,
>
> The following two 'df's should be the same, although their
> constructions are different.
But they aren't the same.

df1 <- data.frame(X=c(1, 2, 3), Y=c(4, 5, 6))
df2 <- data.frame(X=1:3, Y=4:6)
identical(df1, df2)

yields FALSE

See

str(df1)
str(df2)

to see how they differ.



  But the results of paste() are different.
> I don't see this is explained in ?paste. Could you help me understand
> why it is like this?
>
>> df=data.frame(X=c(1, 2, 3), Y=c(4, 5, 6))
>> df
>    X Y
> 1 1 4
> 2 2 5
> 3 3 6
>> paste(df)
> [1] "c(1, 2, 3)" "c(4, 5, 6)"
>> df=data.frame(X=1:3, Y=4:6)
>> df
>    X Y
> 1 1 4
> 2 2 5
> 3 3 6
>> paste(df)
> [1] "1:3" "4:6"
>>
>
>

At the risk of repeating a post I haven't read, the two constructs are
different because 1:3 returns a vector of integers (class "integer")
and
c(1, 2, 3) is a bit more conservative about what '1' and the like mean
and returns a vector of class "numeric".

lapply(df1, class)
lapply(df2, class)



On 08/01/2010 08:48 PM, thmsfuller066 at gmail.com
wrote:
> Hi,
>
> The following two 'df's should be the same, although their
> constructions are different.
But they aren't the same.

df1 <- data.frame(X=c(1, 2, 3), Y=c(4, 5, 6))
df2 <- data.frame(X=1:3, Y=4:6)
identical(df1, df2)

yields FALSE

See

str(df1)
str(df2)

to see how they differ.



  But the results of paste() are different.
> I don't see this is explained in ?paste. Could you help me understand
> why it is like this?
>
>> df=data.frame(X=c(1, 2, 3), Y=c(4, 5, 6))
>> df
>    X Y
> 1 1 4
> 2 2 5
> 3 3 6
>> paste(df)
> [1] "c(1, 2, 3)" "c(4, 5, 6)"
>> df=data.frame(X=1:3, Y=4:6)
>> df
>    X Y
> 1 1 4
> 2 2 5
> 3 3 6
>> paste(df)
> [1] "1:3" "4:6"
>>
>
>
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______________________________________________
R-help at r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.


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