Re: [R] When creating a data frame with data.frame() transforms integers into factors
1. Please always cc. the list; do not reply just to me.
2. OK, I see. I ERRED. Had you cc'ed the list, someone might have
pointed this out. The correct example reproduces what you saw.
z- sample(1:10,30,rep=TRUE)
table(z)
w - data.frame(table(z))
w
z Freq
1 12
2 23
3 31
4 43
5 55
6 63
7 75
8 84
9 91
10 103
sapply(w,class)
z Freq
factor integer
This is exactly what is expected and documented. See ?table. So the
question is: What do you expect? table() produces an array whose
cross-classifying factors are the dimensions. data.frame converts this
into a data frame. Perhaps the following will help clarify:
z - data.frame(fac1= sample(LETTERS[1:3],10,rep=TRUE),
fac2 = sample(c(j,k),10,rep=TRUE))
z
fac1 fac2
1 Ak
2 Bk
3 Ck
4 Ck
5 Bk
6 Ck
7 Ck
8 Aj
9 Aj
10Cj
table(z)
fac2
fac1 j k
A 2 1
B 0 2
C 1 4
data.frame(table(z))
fac1 fac2 Freq
1Aj2
2Bj0
3Cj1
4Ak1
5Bk2
6Ck4
table(z['fac1'])
A B C
3 2 5
data.frame(table(z['fac1']))
Var1 Freq
1A3
2B2
3C5
Cheers,
Bert
On Sat, May 25, 2013 at 6:54 PM, António Camacho toin...@gmail.com wrote:
Hello Bert
Thanks for your prompt reply.
I tried your example and it worked without a problem.
But what i want is to create a data frame from the output of the function
table(), so in your example i tried sapply(data.frame(tbl),class) and the
output was z -- factor and Freq ---integer.
What is happening in the table() function that is transforming the integers
in z into values with labels ?
because when i do names(tbl) it returns each value of z as a name
I read the manual for [ but i didn't understand it completely. I have to
read the introduction to R more carefully.
I also tried using [, [[ and $ for the extraction of the values from
the 'posts' column, but the problem persisted.
Like i said, this code was taken from an example in a webpage. I contacted
the author and he confirmed me that the code worked on his machine, that was
running R 2.15.1
Maybe something changed between versions in the data.frame() ??
I really don't understant what I am doing wrong.
António
On 2013/05/26, at 01:44, Bert Gunter wrote:
Huh?
z - sample(1:10,30,rep=TRUE)
tbl - table(z)
tbl
z
1 2 3 4 5 6 7 8 9 10
4 3 2 6 3 3 2 2 2 3
data.frame(z)
z
1 5
2 2
3 4
4 1
5 6
6 4
7 10
8 4
9 3
10 8
11 10
12 4
13 3
14 9
15 2
16 2
17 6
18 1
19 4
20 7
21 9
22 10
23 7
24 5
25 5
26 6
27 8
28 1
29 1
30 4
sapply(data.frame(z),class)
z
integer
Your error: you used df['posts'] . You should have used df[,'posts'] .
The former is a data frame. The latter is a vector. Read the
Introduction to R tutorial or ?[ if you don't understand why.
-- Bert
-- Bert
On Sat, May 25, 2013 at 12:36 PM, António Camacho toin...@gmail.com
wrote:
Hello
I am novice to R and i was learning how to do a scatter plot with R using
an example from a website.
My setup is iMac with Mac OS X 10.8.3, with R 3.0.1, default install,
without additional packages loaded
I created a .csv file in vim with the following content
userID,user,posts
1,user1,581
2,user2,281
3,user3,196
4,user4,150
5,user5,282
6,user6,184
7,user7,90
8,user8,74
9,user9,45
10,user10,20
11,user11,3
12,user12,1
13,user13,345
14,user14,123
i imported the file into R using : ' df - read.csv('file.csv')
to confirm the data types i did : 'sappily(df, class) '
that returns userID -- integer ; user --- factor ; posts ---
integer
then i try to create another data frame with the number of posts and its
frequencies,
so i did: 'postFreqCount-data.frame(table(df['posts']))'
this gives me the postFreqCount data frame with two columns, one called
'Var1' that has the number of posts each user did, and another collumn
'Freq' with the frequency of each number of posts.
the problem is that if i do : 'sappily(postFreqCount['Var1'],class)' it
returns factor.
So the data.frame() function transformed a variable that was integer
(posts) to a variable (Var1) that has the same values but is factor.
I want to know how to prevent this from happening. How do i keep the
values
from being transformed from integer to factor ?
Thank you for your help
António
[[alternative HTML version deleted]]
__
R-help@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.
--
Bert Gunter
Genentech Nonclinical Biostatistics
Internal Contact Info:
Phone: 467-7374
Website:
Re: [R] When creating a data frame with data.frame() transforms integers into factors
Hello Bert.
I didn't reply to the list because i forgot. I hit reply instead of reply
all
Thanks for your example.
I understood now that i was trying to do something that didn't made sense and
that was why it failed.
I should have used an histogram do do a graph of the frequency of each number
of 'posts' instead of going the convoluted way around and trying to do a
scatterplot.
I now understand that table() transforms each value of the variable into a
factor and counts how many times it shows up. It makes sense that these
factors are then tranformed into character when in the data frame, because
they are not a quantity, but the representation of the number.
Thanks for the help. Problem solved.
António Brito Camacho
No dia 26/05/2013, às 15:00, Bert Gunter gunter.ber...@gene.com escreveu:
1. Please always cc. the list; do not reply just to me.
2. OK, I see. I ERRED. Had you cc'ed the list, someone might have
pointed this out. The correct example reproduces what you saw.
z- sample(1:10,30,rep=TRUE)
table(z)
w - data.frame(table(z))
w
z Freq
1 12
2 23
3 31
4 43
5 55
6 63
7 75
8 84
9 91
10 103
sapply(w,class)
z Freq
factor integer
This is exactly what is expected and documented. See ?table. So the
question is: What do you expect? table() produces an array whose
cross-classifying factors are the dimensions. data.frame converts this
into a data frame. Perhaps the following will help clarify:
z - data.frame(fac1= sample(LETTERS[1:3],10,rep=TRUE),
fac2 = sample(c(j,k),10,rep=TRUE))
z
fac1 fac2
1 Ak
2 Bk
3 Ck
4 Ck
5 Bk
6 Ck
7 Ck
8 Aj
9 Aj
10Cj
table(z)
fac2
fac1 j k
A 2 1
B 0 2
C 1 4
data.frame(table(z))
fac1 fac2 Freq
1Aj2
2Bj0
3Cj1
4Ak1
5Bk2
6Ck4
table(z['fac1'])
A B C
3 2 5
data.frame(table(z['fac1']))
Var1 Freq
1A3
2B2
3C5
Cheers,
Bert
On Sat, May 25, 2013 at 6:54 PM, António Camacho toin...@gmail.com wrote:
Hello Bert
Thanks for your prompt reply.
I tried your example and it worked without a problem.
But what i want is to create a data frame from the output of the function
table(), so in your example i tried sapply(data.frame(tbl),class) and the
output was z -- factor and Freq ---integer.
What is happening in the table() function that is transforming the integers
in z into values with labels ?
because when i do names(tbl) it returns each value of z as a name
I read the manual for [ but i didn't understand it completely. I have to
read the introduction to R more carefully.
I also tried using [, [[ and $ for the extraction of the values from
the 'posts' column, but the problem persisted.
Like i said, this code was taken from an example in a webpage. I contacted
the author and he confirmed me that the code worked on his machine, that was
running R 2.15.1
Maybe something changed between versions in the data.frame() ??
I really don't understant what I am doing wrong.
António
On 2013/05/26, at 01:44, Bert Gunter wrote:
Huh?
z - sample(1:10,30,rep=TRUE)
tbl - table(z)
tbl
z
1 2 3 4 5 6 7 8 9 10
4 3 2 6 3 3 2 2 2 3
data.frame(z)
z
1 5
2 2
3 4
4 1
5 6
6 4
7 10
8 4
9 3
10 8
11 10
12 4
13 3
14 9
15 2
16 2
17 6
18 1
19 4
20 7
21 9
22 10
23 7
24 5
25 5
26 6
27 8
28 1
29 1
30 4
sapply(data.frame(z),class)
z
integer
Your error: you used df['posts'] . You should have used df[,'posts'] .
The former is a data frame. The latter is a vector. Read the
Introduction to R tutorial or ?[ if you don't understand why.
-- Bert
-- Bert
On Sat, May 25, 2013 at 12:36 PM, António Camacho toin...@gmail.com
wrote:
Hello
I am novice to R and i was learning how to do a scatter plot with R using
an example from a website.
My setup is iMac with Mac OS X 10.8.3, with R 3.0.1, default install,
without additional packages loaded
I created a .csv file in vim with the following content
userID,user,posts
1,user1,581
2,user2,281
3,user3,196
4,user4,150
5,user5,282
6,user6,184
7,user7,90
8,user8,74
9,user9,45
10,user10,20
11,user11,3
12,user12,1
13,user13,345
14,user14,123
i imported the file into R using : ' df - read.csv('file.csv')
to confirm the data types i did : 'sappily(df, class) '
that returns userID -- integer ; user --- factor ; posts ---
integer
then i try to create another data frame with the number of posts and its
frequencies,
so i did: 'postFreqCount-data.frame(table(df['posts']))'
this gives me the postFreqCount data frame with two columns, one called
'Var1' that has the number of posts each user did, and another collumn
'Freq' with the frequency of each
Re: [R] When creating a data frame with data.frame() transforms integers into factors
Antonio-
What exactly do you want as output? You stated you wanted a scatter plot,
but which variable do you want on the X axis and which variable do you want
on the Y axis?
-tgs
On Sat, May 25, 2013 at 3:36 PM, António Camacho toin...@gmail.com wrote:
Hello
I am novice to R and i was learning how to do a scatter plot with R using
an example from a website.
My setup is iMac with Mac OS X 10.8.3, with R 3.0.1, default install,
without additional packages loaded
I created a .csv file in vim with the following content
userID,user,posts
1,user1,581
2,user2,281
3,user3,196
4,user4,150
5,user5,282
6,user6,184
7,user7,90
8,user8,74
9,user9,45
10,user10,20
11,user11,3
12,user12,1
13,user13,345
14,user14,123
i imported the file into R using : ' df - read.csv('file.csv')
to confirm the data types i did : 'sappily(df, class) '
that returns userID -- integer ; user --- factor ; posts ---
integer
then i try to create another data frame with the number of posts and its
frequencies,
so i did: 'postFreqCount-data.frame(table(df['posts']))'
this gives me the postFreqCount data frame with two columns, one called
'Var1' that has the number of posts each user did, and another collumn
'Freq' with the frequency of each number of posts.
the problem is that if i do : 'sappily(postFreqCount['Var1'],class)' it
returns factor.
So the data.frame() function transformed a variable that was integer
(posts) to a variable (Var1) that has the same values but is factor.
I want to know how to prevent this from happening. How do i keep the values
from being transformed from integer to factor ?
Thank you for your help
António
[[alternative HTML version deleted]]
__
R-help@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.
[[alternative HTML version deleted]]
__
R-help@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.
Re: [R] When creating a data frame with data.frame() transforms integers into factors
Huh?
z - sample(1:10,30,rep=TRUE)
tbl - table(z)
tbl
z
1 2 3 4 5 6 7 8 9 10
4 3 2 6 3 3 2 2 2 3
data.frame(z)
z
1 5
2 2
3 4
4 1
5 6
6 4
7 10
8 4
9 3
10 8
11 10
12 4
13 3
14 9
15 2
16 2
17 6
18 1
19 4
20 7
21 9
22 10
23 7
24 5
25 5
26 6
27 8
28 1
29 1
30 4
sapply(data.frame(z),class)
z
integer
Your error: you used df['posts'] . You should have used df[,'posts'] .
The former is a data frame. The latter is a vector. Read the
Introduction to R tutorial or ?[ if you don't understand why.
-- Bert
-- Bert
On Sat, May 25, 2013 at 12:36 PM, António Camacho toin...@gmail.com wrote:
Hello
I am novice to R and i was learning how to do a scatter plot with R using
an example from a website.
My setup is iMac with Mac OS X 10.8.3, with R 3.0.1, default install,
without additional packages loaded
I created a .csv file in vim with the following content
userID,user,posts
1,user1,581
2,user2,281
3,user3,196
4,user4,150
5,user5,282
6,user6,184
7,user7,90
8,user8,74
9,user9,45
10,user10,20
11,user11,3
12,user12,1
13,user13,345
14,user14,123
i imported the file into R using : ' df - read.csv('file.csv')
to confirm the data types i did : 'sappily(df, class) '
that returns userID -- integer ; user --- factor ; posts ---
integer
then i try to create another data frame with the number of posts and its
frequencies,
so i did: 'postFreqCount-data.frame(table(df['posts']))'
this gives me the postFreqCount data frame with two columns, one called
'Var1' that has the number of posts each user did, and another collumn
'Freq' with the frequency of each number of posts.
the problem is that if i do : 'sappily(postFreqCount['Var1'],class)' it
returns factor.
So the data.frame() function transformed a variable that was integer
(posts) to a variable (Var1) that has the same values but is factor.
I want to know how to prevent this from happening. How do i keep the values
from being transformed from integer to factor ?
Thank you for your help
António
[[alternative HTML version deleted]]
__
R-help@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.
--
Bert Gunter
Genentech Nonclinical Biostatistics
Internal Contact Info:
Phone: 467-7374
Website:
http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm
__
R-help@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.
