similar to: R book

Displaying 20 results from an estimated 4000 matches similar to: "R book"

2004 May 13
3
storage of lm objects in a database
Hello, I'd like to use DBI to store lm objects in a database. I've to analyze many of linear models and I cannot store them in a single R-session (not enough memory). Also it'd be nice to have them persistent. Maybe it's possible to create a compact binary representation of the object (the kind of format created created by "save"), so that one doesn't need to write
2003 Oct 17
4
sub data frame by expression
Hi All, I've the following data frame with 54 rows and 4 colums: > x Ratio Dose Time Batch R.010mM.04h.NEW 0.02 010mM 04h NEW R.010mM.04h.NEW.1 0.07 010mM 04h NEW ... R.010mM.24h.NEW.2 0.06 010mM 24h NEW R.010mM.04h.OLD 0.19 010mM 04h OLD ... R.010mM.04h.OLD.1 0.49 010mM 04h OLD R.100mM.24h.OLD 0.40 100mM 24h OLD I'd
2004 May 10
5
R versus SAS: lm performance
Hello, A collegue of mine has compared the runtime of a linear model + anova in SAS and S+. He got the same results, but SAS took a bit more than a minute whereas S+ took 17 minutes. I've tried it in R (1.9.0) and it took 15 min. Neither machine run out of memory, and I assume that all machines have similar hardware, but the S+ and SAS machines are on windows whereas the R machine is Redhat
2003 Sep 05
3
all values from a data frame
Hello, I've a data frame with 15 colums and 6000 rows, and I need the data in a single vector of size 90000 for ttest. Is there such a conversion function in R, or would I have to write my own loop over the colums? thanks for your help + kind regards Arne
2006 Mar 08
5
data import problem
Dear All, I'm trying to read a text data file that contains several records separated by a blank line. Each record starts with a row that contains it's ID and the number of rows for the records (two columns), then the data table itself, e.g. 123 5 89.1791 1.1024 90.5735 1.1024 92.5666 1.1024 95.0725 1.1024 101.2070 1.1024 321 3 60.1601 1.1024 64.8023 1.1024 70.0593
2006 Sep 15
3
graphics and 'layout' question
Hello, I got stuck with a graphics question: I've 3 figures that I present on a single page (window) via 'layout'. The layout is layout(matrix(c(1,1,2,3), 2, 2, byrow=TRUE)); so that the frst plot spans the both columns in row one. Now I'd like to magnify the fist figure so that it takes 20% more vertical space (i.e. more space for the y-axis). How would I do this in R?
2004 Jul 26
5
binning a vector
Hello, I was wondering wether there's a function in R that takes two vectors (of same length) as input and computes mean values for bins (intervals) or even a sliding window over these vectros. I've several x/y data set (input/response) that I'd like plot together. Say the x-data for one data set goes from -5 to 14 with 12,000 values, then I'd like to bin the x-vector in steps of
2004 Jun 28
1
unbalanced design for anova with low number of replicates
Hello, I'm wondering what's the best way to analyse an unbalanced design with a low number of replicates. I'm not a statistician, and I'm looking for some direction for this problem. I've a 2 factor design: Factor batch with 3 levels, and factor dose within each batch with 5 levels. Dose level 1 in batch one is replicated 4 times, level 3 is replicated only 2 times. all
2004 Feb 04
3
number point under-flow
Hello, I've come across the following situation in R-1.8.1 (compile + running under RedHat 7.1): > phyper(24, 514, 5961-514, 53, lower.tail=T) [1] 1 > phyper(24, 514, 5961-514, 53, lower.tail=F) [1] -1.037310e-11 I'd expect the later to be 0 or some very small positive number. Is this a number under-flow of the calculation? Do you think I'm safe if I just set the result to 0
2006 Nov 01
4
splitting very long character string
Hello, I've a very long character array (>500k characters) that need to split by '\n' resulting in an array of about 60k numbers. The help on strsplit says to use perl=TRUE to get better formance, but still it takes several minutes to split this string. The massive string is the return value of a call to xmlElementsByTagName from the XML library and looks like this: ... 12345
2005 Jul 21
4
RandomForest question
Hello, I'm trying to find out the optimal number of splits (mtry parameter) for a randomForest classification. The classification is binary and there are 32 explanatory variables (mostly factors with each up to 4 levels but also some numeric variables) and 575 cases. I've seen that although there are only 32 explanatory variables the best classification performance is reached when
2003 Oct 08
3
updating via CRAN and http
Hello, thanks for the tips on updating packages for 1.8.0. The updating is a real problem for me, since I've to do it sort of manually using my web-browser or wget. I'm behind a firewall that requires http/ftp authentification (username and passwd) for every request it sends to a server outside our intranet. Therefore all the nice tools for automatic updating (cran, cpan ...) don't
2004 Sep 30
2
Boxplot, space to axis
Hello, I've crearted a boxplot with 84 boxes. So fat everything is as I expect, but there is quite some space between the 1st box and axis 2 and the last box and axis 4. Since 84 boxes get very slim anyway I'd like to discribute as much of the horizontal space over the x-axis. Maybe I've forgotten about a graphics parameter? Thanks for your help, Arne
2004 May 14
1
help with memory greedy storage
Hello, I've a problem with a self written routine taking a lot of memory (>1.2Gb). Maybe you can suggest some enhancements, I'm pretty sure that my implementation is not optimal ... I'm creating many linear models and store coefficients, anova p-values ... all I need in different lists which are then finally returned in a list (list of lists). The input is a matrix with 84 rows
2005 Jun 28
2
svm and scaling input
Dear All, I've a question about scaling the input variables for an analysis with svm (package e1071). Most of my variables are factors with 4 to 6 levels but there are also some numeric variables. I'm not familiar with the math behind svms, so my assumtions maybe completely wrong ... or obvious. Will the svm automatically expand the factors into a binary matrix? If I add numeric
2004 Apr 27
2
paste dimnames problem
Hello, I've the following list n: > n [[1]] [1] "NEW" "OLD" "PRG" [[2]] [1] "04h" "24h" [[3]] [1] "000mM" "010mM" "025mM" "050mM" "100mM" where n <- dimnames(some.multidim.array) I'm trying to define a generic function that generates meaningful names from this list, e.g.
2003 Oct 05
2
Jonckheere-Terpstra test
Hello, can anybody here explain what a Jonckheere-Terpstra test is and whether it is implemented in R? I just know it's a non-parametric test, otherwise I've no clue about it ;-( . Are there alternatives to this test? thanks for help, Arne
2006 Feb 02
2
calculating IC50
Hello, I was wondering if there is an R-package to automatically calculate the IC50 value (concentration of a substrance that inhibits cell growth to 50%) for some measurements. kind regards, Arne [[alternative HTML version deleted]]
2003 Nov 27
4
significance in difference of proportions
Hello, I'm looking for some guidance with the following problem: I've 2 samples A (111 items) and B (10 items) drawn from the same unknown population. Witihn A I find 9 "positives" and in B 0 positives. I'd like to know if the 2 samples A and B are different, ie is there a way to find out whether the number of "positives" is significantly different in A and B?
2004 Apr 27
3
Mixed Effects Models in S and S-Plus book
Anybody know where I can get the Pinheiro/Bates book? I can't find a bookstore w/ stock and the publisher says they don't know when they'll have it again. Thanks. -Frank