similar to: R and QSAR equations

Displaying 20 results from an estimated 900 matches similar to: "R and QSAR equations"

2007 Aug 30
1
categorical variable coefficients in QSAR
Dear list: I am interested in the following sort of problem, as is found frequently in the field of QSAR. I have biological activity as a function of chemical structure, with structure defined in a categorical manner in that the SUBSTITUENT is the levels of the POSITION factor. For example, data from Kubinyi (http://www.kubinyi.de/dd-12.pdf) for this type of analysis is presented as follows:
2010 Mar 06
3
scientific (statistical) foundation for Y-RANDOMIZATION in regression analysis
Dear all, I am a statistician doing research in QSAR, building regression models where the dependent variable is a numerical expression of some chemical activity and input variables are chemical descriptors, e.g. molecular weight, number of carbon atoms, etc. I am building regression models and I am confronted with a widely a technique called Y-RANDOMIZATION for which I have difficulties in
2007 Aug 30
5
Single plot multiple levels in x?
Plotting with 2 x axis? One axis inside another, for example salary within state, 1-50 | 50 ? 100 | 100+ | 1- 50 | 50 -100 | 100+ | ? repeated bins for salary AL ! AR ?? more states The values are all stored with a single data frame. I have tried different things with the axis function and done many
2012 Mar 08
2
Regarding randomForest regression
Sir, This query is related to randomForest regression using R. I have a dataset called qsar.arff which I use as my training set and then I run the following function - rf=randomForest(x=train,y=trainy,xtest=train,ytest=trainy,ntree=500) where train is a matrix of predictors without the column to be predicted(the target column), trainy is the target column.I feed the same data
2008 Nov 01
2
antispam plugin problem
Hi people! (Especially Johannes, probably =) I recently switched to DSPAM + antispam plugin combination. Mostly I am happy but there is a problem with calling dspam-exec in order to relearn the messages. Moving messages to spam folder does not work, giving the error message 'Failed to call dspam' to client. I tried to add some debug output and here are the results: This is the output of
2010 Jul 07
2
how to define method for "+" function in a new class
Dear R developers, I have a new class, which I called "Molecule", and have tried to define = a "+" operation for 2 objects of this class. This is what I have written so far, although the method is not complete = (I'm trying to look at it at intermediate stages): setMethod( f=3D"+", signature(x=3D"Molecule",y=3D"Molecule"),
2011 May 19
3
A better way to do this
Hello gurus, I have a dataframe containing two groups viz., 'control' and 'case', each of these groups contains longitudinal data for 100 subjects. I have to plot all these subjects on a single chart and then put a regression line for each of the group for all the subjects. I have written a function to do the chart grpcharts<-function (dat, group,group2,molecule,cutoff){
2011 Apr 29
6
Bigining with a Program of SVR
Hi: I'm starting a research of Support Vector Regression. I want to obtain a model to predict a property A with a set of property B, C, D, ... This problem is very common for example in QSAR models. I want to know some examples and package that could help me in this way. I know about caret and e1071. But I' don't know if this package can work with continues variables.?
2012 Jan 30
1
Need to Write a Code that can find the molecular weight of various compounds
Hi! Just started working at a lab and have only minimal experience with R. I was wondering if there was a way to write a code that would intake a data set of chemical compounds (ex: H2O, CH3) and be able to give an output column of the molecular weight? I tried some really basic coding to try to work with a being a matrix of data with the assigned variables. if (A<-'H')
2003 Jan 14
3
PLS regression?
Hi all, I would like to do some QSAR analysis (quantitative structure activity relationship). I need to use some Partial Least Squares (PLS) regression, but I have not seen this option on the R-project. Is it possible to do this kind of regression on R? thank you in advance best regards, olivier [[alternate HTML version deleted]]
2011 Nov 30
1
Invalid number of components, ncomp
Error in mvr(Kd_nM ~ qsar, ncomp = 6, data = my, validation = "CV", method = "kernelpls") :   Invalid number of components, ncomp How I can fix this? [[alternative HTML version deleted]]
2010 Mar 01
0
Is package "dr" appropriate for reducing the dimensionality of molecules conformational space ?
I anticipate lacking of prior experience with dimensionality reduction problems. Some scientists concerned with drug discovery performed several steered Molecular Dynamics simulations of the alanine-dipeptide molecule dragged by a radial force from an equilibrium conformation to another different equilibrium conformation. They sampled at regular intervals 7 dihedral angles, 5 bending angles, and
2004 Feb 23
1
Reference to use of MLR in industry and biology
I apologize in advance for posting a question not related to R. I need references to papers that use multiple linear regression in an industrial application and also in a biological experiment. This is aimed to biologists/chemists (non-statisticans) so if anyone has written a brilliant paper where the use of multiple regression is important and also understandable to people with little
2005 Oct 10
1
text(x,y,greek character)
Dear list, I would like to plot points with two types of labels, one at the data point (the name of the point) and another offset a bit with another factor which is either of the two greek characters alpha or beta. I have tried to get the routine to plot a greek character with expression() or with substitute() and have not yet had any success. The following only plots the word in english in
2012 Sep 14
0
rcdk package, fingerprint without name?
Hi! I have a question concerning the rcdk package: I generated a test sdf-file with 3 molecules in it and tried to perform clustering by fingerprints and plot the results in a dendogramm. This is what I did: mols <- load.molecules ("molecules.sdf") fp.list <- lapply (mols, get.fingerprint, 'maccs') fp.dist <- fp.sim.matrix (fp.list, method='tanimoto')
2022 Nov 16
2
Trouble with kernel-3.10.0-1160.80.1.el7.x86_64
> > On 2022-11-08 15:49, Orion Poplawski wrote: > > On 11/8/22 13:12, Simon Matter wrote: > > Is anyone else experiencing trouble with > kernel-3.10.0-1160.80.1.el7.x86_64? > > I'm seeing a kernel panics in the kvm module on one of our VM hosts with > > it. > > I did notice a new libvirt
2005 Aug 10
3
Hitachi wip5000
Hi all, Saw on the net the wip5000 SIP wireless phone from Hitachi, a suprising rig. As anyone successfull in making it work with Asterisk? If so, how do you like it? Regards, Francois Random Thought: --------------- Molecule, n.: The ultimate, indivisible unit of matter. It is distinguished from the corpuscle, also the ultimate, indivisible unit of matter, by a closer resemblance to
2012 Oct 05
5
IPv6 & SSL
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi, I have a dual stack server with Dovecot 2.1.10 listening on v4 and v6 Dovecot has a Comodo SSL certificate issued via NameCheap that works as expected with IPv4 in 10-ssl.conf I have enabled these configuraction directives: ssl = yes ssl_cert = < /path/to/file.crt ssl_key = < /path/to/file.key ssl_parameters_regenerate = 202 hours If I
2009 Sep 09
2
ggplot2: mixing colour and linetype in geom_line
Hi all, I try to represent a multiple curve graphic where the x-axis is the temperature and the different y-axes are the different X (X22,X43,X44...) some X corresponds to the same molecule (22 and 44 are for CO2 for instance) so I use the same colour for them. I wanna mix the linetype with the colour to be able to visually see the difference between X43 and X45 The best I have done up to now
2006 Dec 20
3
How to use strings from a data.frame as the argument of an expression() for plot
Greetings, I would like to use a data.frame with strings to feed the expression() in the title of a plot. The way I did this is: molecules <-data.frame(name=c("o3","no","no2"),expression=c("quote(O[3])","quote(NO)","quote(NO[2])")) for (mol in c(5,7,9)) { plot(x, y, type="b",