R help - Aug 2013 - Manipulations of a data frame or list -- rename or re-assign?

If I am to do a lot of pre-processing operations on some data,
comprising many steps such as:

-- despike a set of signals
-- smooth a set of signals
-- filter
-- subset
-- impute missing values

etc... Should I be assigning the result of each operation to a new
object, and then destroying the old one, or is it fine to reassign the
object to itself?

df <- sapply(df, someFunction, arg=10)
OR
df.new <- sapply(df, someFunction, arg=10)

Ben
University of Melbourne

Hello,

Maybe you could keep the original, and reuse only one (another) object 
for the intermidiate steps. That's how I would do it.

Hope this helps,

Rui Barradas

Em 03-08-2013 12:27, Ben Harrison escreveu:
> If I am to do a lot of pre-processing operations on some data,
> comprising many steps such as:
>
> -- despike a set of signals
> -- smooth a set of signals
> -- filter
> -- subset
> -- impute missing values
>
> etc... Should I be assigning the result of each operation to a new
> object, and then destroying the old one, or is it fine to reassign the
> object to itself?
>
> df <- sapply(df, someFunction, arg=10)
> OR
> df.new <- sapply(df, someFunction, arg=10)
>
> Ben
> University of Melbourne
>
> ______________________________________________
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> PLEASE do read the posting guide
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> and provide commented, minimal, self-contained, reproducible code.
>

On 08/03/2013 09:27 PM, Ben Harrison wrote:
> If I am to do a lot of pre-processing operations on some data,
> comprising many steps such as:
>
> -- despike a set of signals
> -- smooth a set of signals
> -- filter
> -- subset
> -- impute missing values
>
> etc... Should I be assigning the result of each operation to a new
> object, and then destroying the old one, or is it fine to reassign the
> object to itself?
>
> df<- sapply(df, someFunction, arg=10)
> OR
> df.new<- sapply(df, someFunction, arg=10)
>
Hi Ben,
If you have read the initial data in from a file you can just use the 
original name. If you don't have another copy of the initial data, it is 
best to save it (e.g. write.table, save) before overwriting the object. 
Fundamentally, don't destroy an object that you can't easily recreate.

Jim