[R] Simple Model in R

[Rui Barradas]

Hello,

What you can do is to write a function to do the change. When you want 
to change a value in column Value, it will update the value in column 
New. Something like this:


fun <- function(data, row, newval){
	data$Value[row] <- newval
	data$New <- c(NA, diff(data$Value))
	data
}

fun(dat, 2, 101.5)


Hope this helps,

Rui Barradas

Em 07-09-2013 12:19, Ankur Seth escreveu:
> Is there a way in which I can setup a model like that?
>
> Regards,
> Ankur Seth
>
>
> On Sat, Sep 7, 2013 at 4:49 PM, Rui Barradas <ruipbarradas at sapo.pt> wrote:
>
>> Hello,
>>
>> It will not change the value automatically, you will have to rerun the
>> code.
>>
>> Rui Barradas
>>
>> Em 07-09-2013 11:52, Ankur Seth escreveu:
>>
>>> Thanks Rui, but this does not change the value in the new column
>>> automatically if I change the value in the data column. Any ideas?
>>>
>>> Regards,
>>> Ankur Seth
>>>
>>>
>>> On Sat, Sep 7, 2013 at 2:11 PM, Rui Barradas <ruipbarradas at sapo.pt>
>>> wrote:
>>>
>>>   Hello,
>>>>
>>>> Try the following.
>>>>
>>>> dat <- read.table(text = "
>>>>
>>>> Date                                Value
>>>> 08/01/2013                        100
>>>> 08/02/2013                         100.5
>>>> 08/03/2013                         102
>>>> ", header = TRUE)
>>>>
>>>>
>>>> dat$New <- c(NA, diff(dat$Value))
>>>> dat
>>>>
>>>>
>>>> Hope this helps,
>>>>
>>>> Rui Barradas
>>>>
>>>> Em 07-09-2013 06:06, Ankur Seth escreveu:
>>>>
>>>>   Hello All,
>>>>>
>>>>> I am trying to build a model in R. I am facing the following problem...
>>>>>
>>>>> My Data Frame contains the following data...
>>>>>
>>>>> Date                                Value
>>>>> 08/01/2013                        100
>>>>> 08/02/2013                         100.5
>>>>> 08/03/2013                         102
>>>>> ....
>>>>>
>>>>> Now I want to add a column to this data frame where New Column Value =
>>>>> Difference of two subsequent observations. For Eg. on 08/02/2013 the new
>>>>> value = 100.5 - 100=0.5
>>>>>
>>>>> I want to do this dynamically such that if I change the value in Value
>>>>> column the new column should recalculate automatically.
>>>>>
>>>>> Is there a way to do this in R?
>>>>>
>>>>> Regards,
>>>>> Ankur Seth
>>>>>
>>>>>           [[alternative HTML version deleted]]
>>>>>
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>>>>>>
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>>>
>>>
>
>