[R-sig-teaching] Create new variables

[Gerrit Eichner]

Hello, Abou,

try

datatest1$z <- 1- datatest1$type
datatest1$xz <- datatest1$x * datatest$z

and try reading an introductory manual/book on R.

  Hth  --  Gerrit

---------------------------------------------------------------------
Dr. Gerrit Eichner                   Mathematical Institute, Room 212
gerrit.eichner at math.uni-giessen.de   Justus-Liebig-University Giessen
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On Tue, 20 Mar 2012, AbouEl-Makarim Aboueissa wrote:

> Dear All:
>
> I need to create new variables based on the old data set:
>
>
> old data:
> ===================
>
> type      x     y
> 0          3     4
> 0          2     2
> 0          4     55
> 0          3     4
> 1          2     3
> 1         11    22
> 1         2      33
> 0         34     11
> 1         2       6
> 0         35     77
> 1         64     8
> 0         32     12
> 0         12     40
> 0         67     30
> 0         3       43
> 1         4       23
> 1         2       15
> 1         5       51
> 0         8       6
> 0         9       23
> 1         56     16
> 1         43     27
> 1         21     17
> 0         12     27
> 0         34     47
>
>
>
>
> datatest<-read.table(file="F:\\00 - Spring 2012\\STA 591\\notes\\Module 2 - Linear Regression and Correlation\\Zar chapters 17-20\\olddata.txt",head=TRUE)
>
> ##### datatest
>
> datatest1<-data.frame(type =datatest[,1], x = datatest[,2], y = datatest[,3])
>
> ##### datatest1
>
>
> I want to get:
> ===============
>
> Create a new variable z as follows:
>
> if type =0 then z=1   and if type = 1 then z=0
>
> then create one more variable called xz = x*z
>
>
> new data should look like this one
> ===============================
>
>
> type     x     y      z      xz
> 0         3     4      1      3
> 0         2     2      1      2
> 0         4     55    1      4
> 0         3     4      1      3
> 1         2     3      0      0
> 1        11    22     0      0
> 1         2     33     0      0
> 0        34    11     1      34
> 1        2      6       0      0
> 0        35     77    1      35
> 1        64     8      0      0
> 0        32     12    1      32
> 0        12     40    1      12
> 0        67     30    1      67
> 0        3       43    1      3
> 1        4       23    0      0
> 1        2       15    0      0
> 1        5       51    0      0
> 0        8       6      1      8
> 0        9       23    1      9
> 1        56     16    0      0
> 1        43     27    0      0
> 1        21     17    0      0
> 0        12     27    1      12
> 0        34     47    1      34
>
>
>
> Thank you very much
> abou
>
>
>
>
>
> ==========================
> AbouEl-Makarim Aboueissa, Ph.D.
> Associate Professor of Statistics
> Graduate Program Coordinator
> Department of Mathematics & Statistics
> University of Southern Maine
> 96 Falmouth Street
> P.O. Box 9300
> Portland, ME 04104-9300
> USA
>
>
> Tel: (207) 228-8389
> Fax: (207) 780-5607
> Email: aaboueissa at usm.maine.edu
>          aboueiss at yahoo.com
>
> Office: 301C Payson Smith
>
>
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>
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