[R] Reading in and writing out one line at a time

[Uwe Ligges]

On 20.05.2010 00:47, sedm1000 wrote:
>
> I hope that somebody can help me with this - I think very simple - issue...?
>
> I am running a package that only accepts one line at a time, but I would
> like to run this package on a dataframe of>500 lines.
>
> Dataframe "d" is a single column:
>
> APPLES
> PEARS
> AUBERGINES
> KUMQUATS
>
> I would like to read one line of my dataframe "d", individually into a new
> frame "f", then execute the program on "f" and it provides an output:
>
>> mash(f)
>
> [[1]]
> [1]  FREDBLOGGS
>
> [2]  250
>
> I would like to record this output to a two column dataframe, "r", such as:
>
> FREDBLOGGS     250
>
> and then repeat the process on the next line of dataframe "d", and so on to
> the end of dataframe "d",writing each line into "r" so that the dataframe
> "r" eventually reads:
>
> FREDBLOGGS     250
> JAMESJONES      175
> TERRYTAITE       892
> HARRYSMITH     320
>
>
> I'm afraid that I'm new to this, but think that this first step in will be
> very useful in general. Thank you kindly for any help.


This will be slow, therefore I'd suggest to read the whole data frame at 
once and then feed it row by row into your function.

Uwe Ligges