similar to: Stepwise regression and PLS

Dear all, I hope to remove a whole column from a data frame or matrix (> 2000 columns). All value in the column are same. The first thing is to select those columns. For instance, I hope to remove the V3~6 column, for all the value in those colume is zero. V3 V4 V5 V6 V7 V8 V9 V10 1 0 0 0 0 0.000 0.000 0.000 0.000 2 0 0 0 0 0.000 0.000 0.000 0.000 3 0 0 0

Dear all, In one S+ program, I found the following code. if (impres) cat("blah blah blah \n") Would someone here like to tell me what's the counterpart in R to impres in S+? Thanks in advance! Best wishes, Jinsong ===== (Mr.) Jinsong Zhao Ph.D. Candidate School of the Environment Nanjing University 22 Hankou Road, Nanjing 210093 P.R. China E-mail: jinsong_zh at yahoo.com

Dear all, I found pls.pcr package will give different results if the data are centered and scaled using scale(). I am not sure about when I should scale my data, and whether the dependent variable should be scaled. If the dependent variable is scaled, how I give a prediction to the real data? I appreciate for any suggestions and comments. Best regards, Jinsong ===== (Mr.) Jinsong Zhao Ph.D.

Dear all, I have encountered a problem when perform stepwise regression. The dataset have more 9 independent variables, but 7 observation. In R, before performing stepwise, a lm object should be given. fm <- lm(y ~ X1 + X2 + X3 + X11 + X22 + X33 + X12 + X13 + X23) However, summary(fm) will give: Residual standard error: NaN on 0 degrees of freedom Multiple R-Squared: 1, Adjusted

Dear all, The following is a example that I run and hope to get a linear model. However, I find the lm() can not give correct coefficients for the linear model. I hope it's just my own mistake. Please help. TIA. Regards, Jinsong > x [1] 3.760216 3.997288 3.208872 3.985417 3.265704 3.497505 2.923540 3.193937 [9] 3.102787 3.419574 3.169374 2.928510 3.153821 3.100385 3.768770 3.610583

Dear R-helpers, I am trying to do a stepwise procedure in which I want to force some variables in the model. I have searched around and it seems that only leaps package allows to force the variable in the stepwise procedure. I use the leaps package and use the regsubsets(lm1, force.in = 1, data) to force 1 variable in the model. However, the force.in command only allow me to force 1 variable

Hi, Is there any facility in R to perform a stepwise process on a model, which will remove any highly-correlated explanatory variables? I am told there is in SPSS. I have a large number of variables (some correlated), which I would like to just chuck in to a model and perform stepwise and see what comes out the other end, to give me an idea perhaps as to which variables I should focus on. Thanks

I would like to run a loop in R. I have never done this before, so I would be very grateful for your help ! 1. I have a sample set: 25 objects. I would like to draw 1 object from it and use it as a test set for my future external validation. The remaining 24 objects I would like to use as a training set (to select a model). I would like to repeat this process until all 25 objects are used as a

Hi there, I tried to export the names of country to a csv file with write.csv(). In the resulted file, ?land was coverted to <c5>land. Is there any way could prevent this happening? Thanks! > abc [1] "?land" > write.table(abc, file = "") "x" "1" "<c5>land" Best, Jinsong

Hi there, In SPSS, small piece of data can be input as following: DATA LIST LIST /x1 x2 x3 x4 x5 . BEGIN DATA 5700 12.8 2500 270 25000 1000 10.9 600 10 10000 3400 8.8 1000 10 9000 3800 13.6 1700 140 25000 4000 12.8 1600 140 25000 8200 8.3 2600 60 12000 1200 11.4 400 10 16000 9100 11.5 3300 60 14000 9900 12.5 3400 180 18000 9600 13.7 3600 390 25000

Hi there, I am a Chinese R user. I hope to display Chinese character in a plot, and than save it in PostScript format. I have read the article titled "Non-Standard Fonts in PostScript and PDF Graphics", especially the section about CJK fonts. I also tried the code: > pdf("chinese.pdf", width=3, height=1) > grid.text("\u4F60\u597D", y=2/3,

Dear all, I am wondering why the step() procedure in R has the description 'Select a formula-based model by AIC'. I have been using Stata and SPSS and neither package made any reference to AIC in its stepwise procedure, and I read from an earlier R-Help post that step() is really the 'usual' way for doing stepwise (R Help post from Prof Ripley, Fri, 2 Apr 1999 05:06:03

Hi there, I don't know why the following codes are return different results. > ifelse(3 > 2, 1:3, length(1:3)) [1] 1 > if (3 > 2) 1:3 else length(1:3) [1] 1 2 3 Any hints? Best, Jinsong

Hi there, Why the same string is displayed in different form? > abc[,1] [1] "?land" "Afghanistan" > abc name 1 <c5>land 2 Afghanistan And more... > dput(abc, "aa.txt") > dget("aa.txt") name 1 <c5>land 2 Afghanistan > dget("aa.txt")[,1] [1] "<c5>land"

Hi there, I hope to draw a plot like this: http://www.sg-chem.net/swizard/Ru-bqdi-spectra.gif is it possible to draw it using R? thanks for any suggestions. regards, Jinsong

Hello, I hope to plot my data in a dot diagram, something like the output of the last example of layout function in graphics package. The only difference is that I need the rectangle in histogram is replaced by dot. Thanks in advance. Best wishes, Jinsong Zhao

Hi there, According to ?par, 'font' is an integer which specifies which font to use for text, that 1 corresponds to plain text (the default), 2 to bold face, 3 to italic and 4 to bold italic. When I test Chinese character in pdf(), I found that 1 to bold face, 2 to italic, 3 to bold italic, 4 to symbol. and I don't find how to set plain text. In the following code, the font to use

It looks like an encoding problem. It works fine for me with R encoding set to UTF-8 Here is part of my sessionInfo() results [1] LC_CTYPE=en_CA.UTF-8 LC_NUMERIC=C [3] LC_TIME=en_CA.UTF-8 LC_COLLATE=en_CA.UTF-8 [5] LC_MONETARY=en_CA.UTF-8 LC_MESSAGES=en_CA.UTF-8 I would suggest issuing the command sessionInfo() and seeing what your encoding is. On Tue, 20 Oct 2020 at 08:22,

On 2020/10/20 17:23, Dr Eberhard W Lisse wrote: > ?file.write() > > look for fileEncoding? > > el > There is no file.write(). I have tried fileEncoding = "utf8" and "latin1" in write.csv(). However, it does not have effect. The output is is <U+00C5>land or <c5>land. Best, Jinsong > On 20/10/2020 11:13, Jinsong Zhao wrote: >> Hi

Hi there, I hope to modify values in a vector or matrix in the following code: for (i in 1:9) { assign(paste("a.", i, sep = ""), 1:i) get(paste("a.", i, sep = ""))[i] <- i+50 } I get the following error message: Error in get(paste("a.", i, sep = ""))[i] <- i + 50 : target of assignment expands to non-language object