Displaying 20 results from an estimated 1000 matches similar to: "row-wise means"
2009 Oct 19
2
Filtering on a dataframe- newbie question
Hi,
newbie question. I have a data-frame with 3 named columns: Name, Obs1, Obs2.
The Name column members are made of alphanumeric characters: T1, T2, T3 etc.
I would like to acess only that subset of the data-frame with Name == T44.
X <- dataframe[dataframe$Name=='T44'] does not work.
Any ideas on how to do this?
I'm sure I'm missing a simple concept here.
Thanks,
Anjan
--
2009 Jan 22
3
quantile question
Hi,
A simple quantile question:
I need to calculate the 95% and 5% quantiles (aka percentiles) for the
following data:
67.12
64.51
62.06
55.45
51.41
43.78
10.74
10.14
if I use the formula: 95% quantile point= 95 (8+1)/100, I get the 8.55th
point as the 95% quantile. Which does not make too much sense as I have only
8 data points.
The other option is to use (95*8)/100 = 7.6th data point (which can
2009 Jan 19
3
Perl-R bridge
Hi,
I'm planning to access R from my perl scripts.
The only noteworthy bridge seems to be
Statistics-R-0.03<http://search.cpan.org/%7Ectbrown/Statistics-R/lib/Statistics/R.pm>.
Would anyone like to share their experience with this Perl-R bridge?
I'd like to install it in a Mac OS X.
Suggestions on alternate solutions will be appreciated.
Thanks in advance,
Anjan
--
2008 Sep 09
2
printing all rows
Hi,
my data table has 38939 rows. R prints the first 11111 columns and then
prints an error message:[ reached getOption("max.print") -- omitted 27821
rows ]].
is it possible to set the maxprint parameter so that R prints all the rows?
tia,
anjan
--
=============================
anjan purkayastha, phd
bioinformatics analyst
whitehead institute for biomedical research
nine cambridge
2008 Nov 15
3
Statistics forums
Hi,
Given that the R forum is mostly a site to discuss issues related to the
language, are there any forums that discuss statistical issues? I am
specifically interested in the statistical issues in experimental design.
TIA,
Anjan
--
=============================
anjan purkayastha, phd
bioinformatics analyst
whitehead institute for biomedical research
nine cambridge center
cambridge, ma 02142
2009 Oct 03
2
Calculating the average after adding 3 matrices
Hi all,
Here is my problem:
I have 3 matrices , A, B, C.
Each is an nXn matrix.
I need to create matrix D such that : D[i,j]= (A[i,j]+B[i,j]+C[i,j])/3.
Being a newbie this is proving to be a challenge.
Any ideas on how best to accomplish this?
Thanks!
Anjan
--
=============================
anjan purkayastha, phd
bioinformatics analyst
whitehead institute for biomedical research
nine cambridge
2008 Oct 06
1
package question
hi,
am new to R. what command do i use to check of certain packages have been
loaded?
Also, it seems that most packages come with "vignette"- is this a document
that describes the usage of the package?
thanks for your help,
anjan
--
=============================
anjan purkayastha, phd
bioinformatics analyst
whitehead institute for biomedical research
nine cambridge center
cambridge, ma
2009 Feb 17
1
Uninstall question
I need to uninstall R 2.7.1 from my Mac. What is the best way to uninstall
it? Simply delete the R icon in the Applications folder?
Or is it more involved?
TIA,
Anjan
--
=============================
anjan purkayastha, phd
bioinformatics analyst
whitehead institute for biomedical research
nine cambridge center
cambridge, ma 02142
purkayas [at] wi [dot] mit [dot] edu
703.740.6939
[[alternative
2009 Jul 18
1
Plotting question
Hi I have a data set that needs to be plotted (see below)
When I plot it using the simple plot(read_count ~ Cn), I get box plots for
the read_count numbers plotted according to Cn. The Cn's on the x-axis are
ordered: 10000, 100, 1000, 40, 400, 4000...
How do I plot so that Cn is plotted on the x-axis in an ascending order: 40,
60, 80, .......10000?
Thanks for your help.
Anjan
ID
2009 Apr 22
2
drawing a plot with SEM
I have a data matrix:
repeat1 repeat2
1 30 34
2 12 23
3 50 13
4 56 98
.
.
.
I would like to plot for the mean and standard error of mean of repeat 1 and
repeat2 for each row.
Any pointers on how to do this in R?
TIA,
Anjan
--
=============================
anjan purkayastha, phd
bioinformatics analyst
whitehead
2009 Aug 31
4
Book on R programming
Most books on R I come across describe running statistical procedures in R.
Any suggestions on a good book that teaches *programming* in R?
Thanks,
Anjan
--
=============================
anjan purkayastha, phd
bioinformatics analyst
whitehead institute for biomedical research
nine cambridge center
cambridge, ma 02142
purkayas [at] wi [dot] mit [dot] edu
703.740.6939
[[alternative HTML version
2011 Jan 05
3
Plotting colour-coded points
Hi,
I have a file of the following type:
id a b
1 0.5 5
2 0.7 15
3 1.6 7
4 0.5 25
....................
I would like to plot the data in column a on the y-axis and the
corresponding data in column id on the x-axis, so plot(a~id). However I
would like to colour these points according to the data in column b.
column b data may be colour coded into the
2010 Oct 12
3
How do I tell whether two vectors are identical?
Hi,
I have two vectors, each of length 45000.
How do I compare the vectors to ascertain if they are identical. Secondly if
they are NOT identical, how do I determine the indices of positions at which
the vectors differ?
Thanks,
Anjan
--
===================================
anjan purkayastha, phd.
research associate
fas center for systems biology,
harvard university
52 oxford street
cambridge ma
2010 Dec 29
2
subset question
Hi,
I'm having a problem with a step that should be pretty simple.
I have a dataframe, d, with column names : gene s1 s2 s3. The column "gene"
stores an Id; the rest of the columns store intensity data.
I would like to extract the rows for gene Ids i1, i2, i3 ( I know a priori
that those rows exist).
So I do this:
subset(d, gene %in% c(i1, i2, i3)).
This does not give me the
2010 Oct 07
2
problem with colors
Hi,
I have a data set of 47 columns. I would like to create a boxplot for each
column, each boxplot of a different colour.
So I created a vector "col1". This vector has a subset of the colors
returned by color()- "red", "cyan", "green" etc.
Now I use the command: boxplot(dataset, col= col1) expecting to see 47
boxplots, each of a different colour.
Here is
2010 May 30
3
subsetting
Hi,
I have a data-frame, r (column names below), that needs subsetting:
date, time, strain, gene, deltact
When I try to subset r by applying selection criteria on two columns I get
an empty data frame. For example I would like to extract all rows that have
time == 0h and strain == ROC.
So, t <- subset(r, (r$time == "0h" && r$strain == "ROC"), select= c(time,
2010 Oct 05
2
Plotting x-axis labels perpendicular to the axis
Hi,
The following command: axis(1, at= 1:50, labels= sampleNames(data)) produces
an X-axis with 50 ticks and labels drawn from the sampleNames namespace.
Problem is the labels at each tick are printed parallel to the x-axis and
thus run into each other. How do I specify for the labels to be printed
perpendicular to the x-axis?
Thanks in advance.
Anjan
--
===================================
anjan
2010 May 29
1
modifying only certain rows in a data-frame
Hi,
I have a data-frame r (shown below is a subset) with the following column
names:
date time sample vct norm hct deltact
$time has 8 levels: 0h, 0.5h, .....24h. $deltact holds real numbers.
I want to subset this dataframe by the levels of $time. For all the rows
which have r$time == "0h" I would like to convert the present value of
r$deltact to 0.
Any pointers to a
2010 Oct 24
1
Subsetting a dataframe
Hi,
I have a dataframe with 43 columns and a 1000 rows. Each entry in the
dataframe can be either P or A.
here is a small chunk:
c1 c2 ... c43
r100 P A ... P
r101 A A ... A
r102 P P ... P
How does one subset this data frame to select those rows that have only P's
in them?
Thanks in advance.
Anjan
--
===================================
2010 Nov 01
1
Error message when creating a dataframe
Hi,
I'm creating a data frame of 24 columns and 45101 rows.
Here is the error I get:
R(147,0xa04d8720) malloc: *** mmap(size=184320) failed (error code=12)
*** error: can't allocate region
*** set a breakpoint in malloc_error_break to debug
Any idea of what I can do to trouble-shoot?
Attached is the session info:
R version 2.11.1 (2010-05-31)
i386-apple-darwin9.8.0
locale:
[1]