an entry level (stupid) question

-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
project.org] On Behalf Of Yanyuan Zhu
Sent: Thursday, December 20, 2012 7:48 AM
To: r-help at r-project.org
Subject: [R] an entry level (stupid) question

Hello all, i'm a newbie to R and now I get stuck by the question, would
anybody help me please?

Suppose, I got the following

test <- data.frame(test1=c(c(0.00, 0.005, 0.01, 0.015, 0.02)))
test

  test1
1 0.000
2 0.005
3 0.010
4 0.015
5 0.020

Now I want another column inside test, named test2
for i=c(1:5), If test$test1[i] is 0, then the value of test$test2[i] is
1/test1[i]
or else If test$test1[i] is not 0, then the value of test$test2[i] is
39

how should i programme in R to make it happen?

thanks a lot!

You probably want to use the ifelse() function, but your description of the problem change zeros into  inf (i.e. infinity) and all other values into 39.  Is that what you really want?


Dan

Daniel J. Nordlund
Washington State Department of Social and Health Services
Planning, Performance, and Accountability
Research and Data Analysis Division
Olympia, WA 98504-5204

Hi Yanyuan

Check out:
   
?"=="
?"["
?"<-"
   
You should be able to assign the column quickly with no more than two lines of code using square brackets and assign.   
   
Or to literally use if, look at:   
   
?"ifelse"
   

Happy Christmas
   
Chris
   

Chris Campbell   
Tel. +44 (0) 1249 705 450?| Mobile. +44 (0) 7929 628349   
mailto:ccampbell at mango-solutions.com?| http://www.mango-solutions.com   
Mango Solutions  
2 Methuen Park 
Chippenham 
Wiltshire  
SN14 OGB 
UK 

-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of Yanyuan Zhu
Sent: 20 December 2012 15:48
To: r-help at r-project.org
Subject: [R] an entry level (stupid) question

Hello all, i'm a newbie to R and now I get stuck by the question, would anybody help me please?

Suppose, I got the following

test <- data.frame(test1=c(c(0.00, 0.005, 0.01, 0.015, 0.02))) test

test1
1 0.000
2 0.005
3 0.010
4 0.015
5 0.020

Now I want another column inside test, named test2 for i=c(1:5), If test$test1[i] is 0, then the value of test$test2[i] is 1/test1[i] or else If test$test1[i] is not 0, then the value of test$test2[i] is 39

how should i programme in R to make it happen?

thanks a lot!


______________________________________________
R-help at r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

--

LEGAL NOTICE\ \ This message is intended for the use of ...{{dropped:18}}

Hello,

Inline.
Em 20-12-2012 15:47, Yanyuan Zhu escreveu:

Hello all, i'm a newbie to R and now I get stuck by the question, would
anybody help me please?

Suppose, I got the following

test <- data.frame(test1=c(c(0.00, 0.005, 0.01, 0.015, 0.02)))
test

   test1
1 0.000
2 0.005
3 0.010
4 0.015
5 0.020

Now I want another column inside test, named test2
for i=c(1:5), If test$test1[i] is 0, then the value of test$test2[i] is
1/test1[i]

Note that this gives 1/0 == Inf.
Anyway, a possibility is

test$test2 <- 39
test$test2[test$test1 == 0] <- 1/test$test1[test$test1 == 0]
test


Hope this helps,

Rui Barradas

or else If test$test1[i] is not 0, then the value of test$test2[i] is 39

how should i programme in R to make it happen?

thanks a lot!

	[[alternative HTML version deleted]]

______________________________________________
R-help at r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.