[R] Small vector into large data frame

Adams, Jean jvadams at usgs.gov
Fri Nov 14 15:56:56 CET 2014


Use the p_f numbers as an "index" of spot$pxlast.  Suppose your data frame
is called mydata,

mydata$newvar <- spot$pxlast[mydata$p_f]

Jean

On Fri, Nov 14, 2014 at 8:48 AM, Francesca Pancotto <
francesca.pancotto at unimore.it> wrote:

> Dear Contributors
> I seem not to get the general rule applying to the use of loops.
> I need some help. I have a database in which i need to generate a variable
> according to the following rule.
>
>
> This is the database head
>
>       bank_name       date px_last       Q_Y p_made p_for p_m p_f
> aba.1       ABA 2006-10-24    1.28 p406-q406    406   406   1   1
> aba.2       ABA 2006-11-30    1.31 p406-q406    406   406   1   1
> aba.3       ABA 2006-10-24    1.29 p406-q107    406   107   1   2
> aba.4       ABA 2006-11-30    1.33 p406-q107    406   107   1   2
> aba.5       ABA 2006-10-24    1.31 p406-q207    406   207   1   3
> aba.6       ABA 2006-11-30    1.35 p406-q207    406   207   1   3
>
>
> the variable p_f takes values from 1 to 19 in a non regular way.
>
> then I have a vector of 19 elements
>
> > spot$pxlast
>  [1] 1.32 1.34 1.35 1.43 1.46 1.58 1.58 1.41 1.40 1.33 1.40 1.46 1.43 1.35
> 1.22 1.36 1.34 1.42 1.42
>
> I need to create a variable to attach to the data frame which is composed
> of 11500 rows that takes values
> 1.32 when p_f==1
> 1.34 when p_f==2
>
> It seems so easy but I cannot find a way to do it in an efficient way.
> Thanks in advance for any help.
>
>
>
> Francesca
>
>
>
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>
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