[R] Basic help on DF creation row by row

[arun]

Hi,

Not sure if this helps.

deviceSummary <- data.frame(item = character(0) ,  value = numeric(0) , unit = character(0) ,stringsAsFactors=FALSE)
newlst<-  list("primitiveSpace",1.1,"mm2")
deviceSummary[nrow(deviceSummary)+1,]<- newlst

newlst2<-  list("primitiveSpace",2.2,"mm2")
 deviceSummary[nrow(deviceSummary)+1,]<- newlst2


 str(deviceSummary)
#'data.frame':    2 obs. of  3 variables:
# $ item : chr  "primitiveSpace" "primitiveSpace"
# $ value: num  1.1 2.2
# $ unit : chr  "mm2" "mm2"
 deviceSummary
#            item value unit
#1 primitiveSpace   1.1  mm2
#2 primitiveSpace   2.2  mm2

A.K.

----- Original Message -----
From: "rolf.kemper at renesas.com" <rolf.kemper at renesas.com>
To: r-help at r-project.org
Cc: 
Sent: Tuesday, October 1, 2013 9:24 AM
Subject: [R] Basic help on  DF creation row by row



Dear Experts

I'm very new to R and after some days or reading and testing  I tried to make my first small application (and failed ...)
In general I would like to work with sqldf , ggplot2 to create some graphical output.

At present I got stuck with this:

PROG #############################################################################
deviceSummary <- data.frame(item = character(0) ,  value = numeric(0) , unit = character(0) )
print ( sapply(deviceSummary, class))

newRow <- c("primitiveSpace", 1.1 , "mm2")
deviceSummary <-rbind(deviceSummary , newRow )
print(deviceSummary)

newRow <- c("primitiveCellSpace", 2.2 , "mm2")
deviceSummary <-rbind(deviceSummary , newRow )
print(deviceSummary )

OUTPUT ############################################################################
    item     value      unit
"factor" "numeric"  "factor"
  X.primitiveSpace. X.1.1. X.mm2.
1    primitiveSpace    1.1    mm2
  X.primitiveSpace. X.1.1. X.mm2.
1    primitiveSpace    1.1    mm2
2              <NA>   <NA>    mm2
Warning messages:
1: In `[<-.factor`(`*tmp*`, ri, value = "primitiveCellSpace") :
  invalid factor level, NA generated
2: In `[<-.factor`(`*tmp*`, ri, value = "2.2") :
  invalid factor level, NA generated

Inserting the first record went fine , but the next one will fail as you can see.
Repeating only the first one (value1.1) went fine.

May be my imagination of DF is totally wrong. Hope someone can guide me.

Thanks a lot

Rolf




Rolf  Kemper, Manager, Mixed Signal Design, Networking, Renesas Electronics Europe GmbH, , Arcadiastr. 10, 40472, Duesseldorf, Germany,  Phone:+49 211
6503-1475, Fax:+49 211 6503-1540, mailto:Rolf.Kemper at renesas.com, http://www.renesas.eu

This message is intended only for the use of the address...{{dropped:24}}

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