Re: [R] create a dummy variables for companies with complete history.
You may want to consider another way of getting your answer that takes
advantage of some of R's features:
# Make some example data
cods - LETTERS[1:10] # Ten companies
yrs - 2010:2014 # 5 years
set.seed(42) # Set random seed so we all get the same values
# Chances of revenue for a given year are 95%
rev - round(rbinom(50, 1, .95)*runif(50, 25, 50), 2)
z - data.frame(expand.grid(year=yrs, cod=cods)[, 2:1], rev)
# Remove years with missing (0) revenue
z - z[z$rev 1, ]
str(z)
'data.frame': 45 obs. of 3 variables:
$ cod : Factor w/ 10 levels A,B,C,D,..: 1 1 1 1 1 2 2 2 2 2 ...
$ year: int 2010 2011 2012 2013 2014 2010 2011 2012 2013 2014 ...
$ rev : num 33.3 33.7 35 44.6 26 ...
# Construct the dummy variable
tbl - xtabs(~cod+year, z)
tbl
year
cod 2010 2011 2012 2013 2014
A11111
B11111
C11111
D10111
E11011
F11111
G11111
H11111
I11101
J01101
dummy - as.integer(apply(tbl, 1, all))
dummy
[1] 1 1 1 0 0 1 1 1 0 0
-
David L Carlson
Department of Anthropology
Texas AM University
College Station, TX 77840-4352
-Original Message-
From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of Michael Dewey
Sent: Wednesday, June 24, 2015 2:12 PM
To: giacomo begnis; r-help@r-project.org
Subject: Re: [R] create a dummy variables for companies with complete history.
Comments below
On 24/06/2015 19:26, giacomo begnis wrote:
Hi, I have a dataset (728 obs) containing three variables code of a company,
year and revenue. Some companies have a complete history of 5 years, others
have not a complete history (for instance observations for three or four
years).I would like to determine the companies with a complete history using
a dummy variables.I have written the following program but there is somehting
wrong because the dummy variable that I have create is always equal to
zero.Can somebody help me?Thanks, gm
z-read.table(file=c:/Rp/cddat.txt, sep=, header=T)
attach(z)
n-length(z$cod) // number of obs dataset
Could also use nrow(z)
d1-numeric(n) // dummy variable
for (i in 5:n) {
if (z$cod[i]==z$cod[i-4]) // cod is the code of a company
{ d1[i]=1} else { d1[i]=0} // d1=1 for a
company with complete history, d1=0 if the history is not complete }d1
Did you really type = which means less than or equals to? If so, try
replacing it with - and see what happens.
When I run the program d1 is always equal to zero. Why?
Once I have create the dummy variable with subset I obtains the code of the
companies with a complete history and finally with a merge I determine a
panel of companies with a complete history.But how to determine correctly
d1?My best regards, gm
[[alternative HTML version deleted]]
__
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--
Michael
http://www.dewey.myzen.co.uk/home.html
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and provide commented, minimal, self-contained, reproducible code.
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] create a dummy variables for companies with complete history.
Giacomo,
Please include some representative data. It is not clear why your offset of 4
(z$cod[i - 4]) is going to be an accurate surrogate for complete data.
Since I do not have your data set or its true structure I am having to guess.
# make 5 copies of 200 companies
companies - paste0(rep(LETTERS[1:4], 5, each = 50), rep(1:50, 5))
companies - companies[order(companies)]
years - rep(1:5, 200)
z - data.frame(cod = companies, year = years,
revenue = round(rnorm(1000, mean = 10, sd = 1)))
# trim this down to the 728 rows you have by pulling out records at random
set.seed(1) # so that you can repeat these results
z - z[sample.int(1000, 728), ]
z - z[order(z$cod, z$year), ]
#No matter how you order these data, your offset approach will not tell you
which companies have full records.
head(z, 10)
cod year revenue
1 A11 112192
2 A12 105840
4 A14 112357
5 A15 91772
7 A102 102601
8 A103 105183
11 A111 101269
12 A112 100719
14 A114 86138
15 A115 105044
#You can do something like the following.
counts - table(z$cod)
complete - names(counts[as.integer(counts) == 5])
# It is probably better to keep the dummy variable inside the dataframe.
z$complete - ifelse(z$cod %in% complete, TRUE, FALSE)
head(z, 20)
cod year revenue complete
1 A11 112192FALSE
2 A12 105840FALSE
4 A14 112357FALSE
5 A15 91772FALSE
7 A102 102601FALSE
8 A103 105183FALSE
11 A111 101269FALSE
12 A112 100719FALSE
14 A114 86138FALSE
15 A115 105044FALSE
20 A125 95872FALSE
21 A131 78513 TRUE
22 A132 90502 TRUE
23 A133 108683 TRUE
24 A134 110711 TRUE
25 A135 87842 TRUE
28 A143 99939FALSE
30 A145 111289FALSE
31 A151 100930FALSE
32 A152 93765FALSE
Do not use HTML. Use plain text. The character string // is not a comment
indicator in R. Do not use attach(). It does not do anything in your example,
but it is poor practice. Always write out TRUE and FALSE
R. Mark Sharp, Ph.D.
msh...@txbiomed.org
On Jun 24, 2015, at 1:26 PM, giacomo begnis gmbeg...@yahoo.it wrote:
Hi, I have a dataset (728 obs) containing three variables code of a company,
year and revenue. Some companies have a complete history of 5 years, others
have not a complete history (for instance observations for three or four
years).I would like to determine the companies with a complete history using
a dummy variables.I have written the following program but there is somehting
wrong because the dummy variable that I have create is always equal to
zero.Can somebody help me?Thanks, gm
z-read.table(file=c:/Rp/cddat.txt, sep=, header=T)
attach(z)
n-length(z$cod) // number of obs dataset
d1-numeric(n) // dummy variable
for (i in 5:n) {
if (z$cod[i]==z$cod[i-4]) // cod is the code of a company
{ d1[i]=1} else { d1[i]=0} // d1=1 for a company with
complete history, d1=0 if the history is not complete }d1
When I run the program d1 is always equal to zero. Why?
Once I have create the dummy variable with subset I obtains the code of the
companies with a complete history and finally with a merge I determine a
panel of companies with a complete history.But how to determine correctly
d1?My best regards, gm
[[alternative HTML version deleted]]
__
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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.
__
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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.
Re: [R] create a dummy variables for companies with complete history.
Please repost your question in plain text rather than HTML - you can
see below that your code got rather mangled. Please also include some
sample data using dput() - made-up data of similar form is fine, but
it's very hard to answer a question based on guessing what the data
look like.
Sarah
On Wed, Jun 24, 2015 at 2:26 PM, giacomo begnis gmbeg...@yahoo.it wrote:
Hi, I have a dataset (728 obs) containing three variables code of a company,
year and revenue. Some companies have a complete history of 5 years, others
have not a complete history (for instance observations for three or four
years).I would like to determine the companies with a complete history using
a dummy variables.I have written the following program but there is somehting
wrong because the dummy variable that I have create is always equal to
zero.Can somebody help me?Thanks, gm
z-read.table(file=c:/Rp/cddat.txt, sep=, header=T)
attach(z)
n-length(z$cod) // number of obs dataset
d1-numeric(n) // dummy variable
for (i in 5:n) {
if (z$cod[i]==z$cod[i-4]) // cod is the code of a company
{ d1[i]=1} else { d1[i]=0} // d1=1 for a company with
complete history, d1=0 if the history is not complete }d1
When I run the program d1 is always equal to zero. Why?
Once I have create the dummy variable with subset I obtains the code of the
companies with a complete history and finally with a merge I determine a
panel of companies with a complete history.But how to determine correctly
d1?My best regards, gm
[[alternative HTML version deleted]]
--
Sarah Goslee
http://www.functionaldiversity.org
__
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] create a dummy variables for companies with complete history.
Comments below
On 24/06/2015 19:26, giacomo begnis wrote:
Hi, I have a dataset (728 obs) containing three variables code of a company,
year and revenue. Some companies have a complete history of 5 years, others
have not a complete history (for instance observations for three or four
years).I would like to determine the companies with a complete history using a
dummy variables.I have written the following program but there is somehting
wrong because the dummy variable that I have create is always equal to zero.Can
somebody help me?Thanks, gm
z-read.table(file=c:/Rp/cddat.txt, sep=, header=T)
attach(z)
n-length(z$cod) // number of obs dataset
Could also use nrow(z)
d1-numeric(n) // dummy variable
for (i in 5:n) {
if (z$cod[i]==z$cod[i-4]) // cod is the code of a company
{ d1[i]=1} else { d1[i]=0} // d1=1 for a
company with complete history, d1=0 if the history is not complete }d1
Did you really type = which means less than or equals to? If so, try
replacing it with - and see what happens.
When I run the program d1 is always equal to zero. Why?
Once I have create the dummy variable with subset I obtains the code of the
companies with a complete history and finally with a merge I determine a panel
of companies with a complete history.But how to determine correctly d1?My best
regards, gm
[[alternative HTML version deleted]]
__
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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.
--
Michael
http://www.dewey.myzen.co.uk/home.html
__
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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.
