[R] Fill in empty cell in data.frame from previous value

Boris Steipe boris.steipe at utoronto.ca
Sun Jun 25 17:23:51 CEST 2017

Run it through a loop. I assume the cell contents is NA (Not Available). Test for it with is.na(). Whenever that returns TRUE, replace the NA value with the value from the previous row.


> On Jun 24, 2017, at 1:49 PM, Christophe Elek <christophe.elek at gmail.com> wrote:
> Hello Total newbie here... I hope I read the guide properly
> I have the following data.frame (I read it from a CSV file I cannot change)
>  names val
> 1 Mandy   1
> 2         2
> 3 John    2
> 4         2
> I want to read the row number 2, but I want the first column to be “Mandy” and not null
> print (frame[2,])
> 2 Mandy   2
> I can manipulate the data.frame once loaded
> How can I fill all cell in column “names” with the previous value ?
> Or is there a function that will get me the row and fill the “names” column ?
> NOTA BENE: I do not want the answer, I want to find it myself but I need guidance
> If there is a function, tell me the library and I will search
> If this is an algorithm, tell me generally how you would do and let me scratch my head first 😊
> Thanks Chris
> 	[[alternative HTML version deleted]]
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