Displaying 20 results from an estimated 20000 matches similar to: "store and retrieve object names in a vector"
2005 Dec 08
2
how to change a dataframe with characters to a numeric matrix?
hi netters,
i have a dataframe TEST like this:
Y1 Y2 Y3
X1 4 7 8
X2 6 2 Z
X3 8 0 1
i would like to change it to a numeric matrix, replacing "Z" with NA
Y1 Y2 Y3
X1 4 7 8
X2 6 2 NA
X3 8 0 1
i've tried the function data.matrix but it didn't work. is there any easy
way to do this?
thanks a lot!
2008 Apr 17
1
how to use a function in aggregate which accepts matrix and outputs matrix?
Dear netters, suppose I have a matrix X [1,] 'c1' 'r6' '150'[2,] 'c1' 'r4' '70'[3,] 'c1' 'r2' '20'[4,] 'c1' 'r5' '90'[5,] 'c2' 'r2' '20'[6,] 'c3' 'r1' '10'I want to apply some funciton to groups of rows by the first column.If the function is just to
2008 Jan 26
3
An R clause to bind dataframes under certain contions
Hi netters,
Suppose I have two data frames X and Y. X has three colnames A, B and C. Y has three colnames A,B and D.
I want to combine them into one matrix, joining the rows having the same A and B values (X$A==Y$A and X$B = Y$B). So the resulting dataframe has four variables/columns: A,B,C and D.
I was wondering what's the best way to do it in R. Could anyone give me some advice?
Thanks!
2007 Jul 19
3
Error: evaluation nested too deeply when doing heatmap with binary distfunction
Hi netters,
I have a matrix X of the size (1000,100). The values are from -3 to +3.
When I tried
heatmap(X,
distfun=function(c),dist(c,method="bin"),hclustfun=function(m),hclust(m,method="average"))
I got the error message:
Error: evaluation nested too deeply: infinite recursion /
options(expressions=)?
However, if I used default parameters for distfunction:
2008 Mar 07
4
locate the rows in a dataframe with some criteria
Hi, netters,
This is probably a rookie question but I couldn't find the answer after hours of searching and trying.
Suppose there'a a dataframe M:
x y
10 A
13 B
8 A
11 A
I want to locate the rows where x >=10 and y="A". I know how to do it to vectors by using
which, but how to do it with the dataframe?
Thank you very much!
Zhihua Li
2008 Jan 26
3
Comparison of aggregate in R and group by in mysql
Hi, netters,
First of all, thanks a lot for all the prompt replies to my earlier question about "merging" data frames in R.
Actually that's an equivalence to the "join" clause in mysql.
Now I have another question. Suppose I have a data frame X with lots of columns/variables:
Name, Age,Group, Type, Salary.
I wanna do a subtotal of salaries:
aggregate(X$Salary,
2005 Jun 23
2
quotient and remainder
hi netters
Is there a function in R that can compute the quotient and remainder of a
division calculation? such that when 11 is given as the dividend and 5
the divider, the function returns 2(quotient) and 1(remainder).
Thanks a lot!
_________________________________________________________________
伱佲伔佈佅伮佋佖 MSN Explorer: http://explorer.msn.com/lccn/
2005 Dec 03
2
how to subset rows using regular expression patterns
hi netters,
i have a dataframe A with several columns(variables). the elements of
column M are character strings. so
A$M=c("ab","abc","bcd","ac","abcd","fg",....."fl").
i wanna extract all the rows where A$M match some regular expression
pattern.
for a simple example, let the pattern be just "ab", i wanna subset
2007 Jul 02
2
working with R graphics remotely
Hi netters,
Now I'm connecting from my local windows machine to a remote linux machine
and launch R out there using SSH. When I tried to create grahics, like
using plot or heatmap, I cannot see the output. Maybe a new R window
displaying the graphics has popped out in the remote machine? Or I need to
change some settings for the graphics to display? I don't know. I googled
it and
2005 Jun 21
2
how to count "associated" factors?
hi netters
Suppose I have a factor X, with 10 elements and 3 levels: A B B C A C B A C
C .
It is easy to count the number of elements for each level:
tapply(X,X,length).
Now I have another factor Y, which formed a matrix with X:
X| A B B C A C B A C C
Y| B B C C C A A A B B
I wanna count the number of elements for each of these conditions: when X=A
and Y=A; when X=A and Y=B; when X=A and
2005 May 13
1
manipulating dataframe according to the values of some columns
hi netters,
I'm a newbie to R and there are some very simple problems puzzeled me for
two days.
I've a dataframe here with several columns different in modes. Two of the
columns are special for me: column 1 has the mode "factor" and column 2 has
the mode "numeric vectors".
The values for column 1 are either "T" or "F". I wanna do two things:
2005 Jul 12
2
how to generate argument from a vector automatically
hi netters
i have a vector NAMES containing a series of variable names:
NAMES=c(x,r,z,m,st,qr,.....nn).
i wanna fit a regression tree by using the code:
my.tree<-tree(y~x+r+z+m+....nn,my.dataframe)
but i don't want to type out "x+r+z+m+....+nn" one by one, as there are so
many variables. besides, sometimes i wanna put the code in a function. so i
need to have the
2007 Jul 18
2
memory error with 64-bit R in linux
Hi netters,
I'm using the 64-bit R-2.5.0 on a x86-64 cpu, with an RAM of 2 GB. The
operating system is SUSE 10.
The system information is:
-uname -a
Linux someone 2.6.13-15.15-smp #1 SMP Mon Feb 26 14:11:33 UTC 2007 x86_64
x86_64 x86_64 GNU/Linux
I used heatmap to process a matrix of the dim [16000,100]. After 3 hours
of desperating waiting, R told me:
cannot allocate vector of size
2005 May 30
3
how to "singlify" entries
hi netters
I have a rather simple question. I have a data frame with two variables X
and Y, both of which are factors. X has 100 levels while Y has 10 levels
only. The data frame has 100 rows in all, so for X the values are unique,
and Y has many replicate values. Now I wanna reduce the data frame into 10
rows only, according to the 10 levels of Y. I don't care which value of X
is in
2005 Aug 26
2
learning decision trees with one's own scoring functins
Hi netters,
I want to learn a decision tree from a series of instances (learning data).
The packages
tree or rpart can do this quite well, but the scoring functions (splitting
criteria) are
fixed in these packages, like gini or something. However, I'm going to use
another scoring
function.
At first I wanna modify the R code of tree or rpart and put my own scoring
function in. But it
2007 Jun 05
1
rJava installation under linux: configuration failed
Hi netter,
Recently I was trying to install rJava. The operating system is suse 10.0,
and the R versionis 2.5.0.
Following the instructions of R Wiki for rJava, I did configuration first:
R CMD javareconf
and then it showed a series of information, from what it seems that java is
in the system and the configuration succeeded.
Then I tried to install rJava:
2010 Feb 18
1
aggregate by column names
Hi,
I've this dataframe:
V1 V5 V6
1 MOD13Q1_2000049 0.1723 A1
2 MOD13Q1_2000049 0.1824 B1
3 MOD13Q1_2000049 0.1824 C1
4 MOD13Q1_2000049 0.1774 A2
5 MOD13Q1_2000049 0.1953 B2
6 MOD13Q1_2000049 0.1824 C2
7 MOD13Q1_2000065 0.1921 A1
8 MOD13Q1_2000065 0.1938 B1
9 MOD13Q1_2000065 0.2009 C1
10 MOD13Q1_2000065 0.2035 A2
11 MOD13Q1_2000065 0.2157 B2
12
2009 Jul 30
4
edit.row.names taking row names from the edited dataframe
Hi all,
I am struggling to work out how to use the rownames from an edited dataframe
rather than the row names from the original dataframe. In my data set i'm
trying to extract several rows of data on particular individuals, i don't
doubt i'm using the long way round but what i have in the way of a script is
this:
##selecting the IDs from the dataframe individually
2012 Apr 19
3
How to "flatten" a multidimensional array into a dataframe?
Hi,
I have a three dimensional array, e.g.,
my.array = array(0, dim=c(2,3,4), dimnames=list( d1=c("A1","A2"),
d2=c("B1","B2","B3"), d3=c("C1","C2","C3","C4")) )
what I would like to get is then a dataframe:
d1 d2 d3 value
A1 B1 C1 0
A2 B1 C1 0
.
.
.
A2 B3 C4 0
I'm sure there is one function to do
2005 Apr 20
1
newby trying to solve a system
Dear R-gurus,
being very new to R, (as well as lazy and not too smart !) I have some
problems (and get lost in the docs) trying to write something to find
the 9 values (A1,B1,C1,A2,B2,C2....C3) which are solutions of a 12
equations system of the form :
> x1-(A1/(A1+B1+C1)) = 0
> y1-(B1/(A1+B1+C1))= 0
> z1-(C1/(A1+B1+C1)) = 0
> 3 same equations with subscript 2
> 3 same