search for: vioravi

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2011 Nov 17
7
Spatial Statistics using R
I am looking for online courses to learn Spatial Statistics using R. Statistics.com is offering an online course in December on the same topic but that schedule doesn't suit mine. Are there any other similar modes for learning spatial statistics using R??? Can someone please advice??? Thank you. Ravi -- View this message in context:
2011 May 20
8
Building Custom GUIs for R
I am looking to build simple GUIs based on the R codes I have. The main objective is to hide the scary R codes from non-programming people and make it easier for them to try out different inputs. For example, 1. The GUI will have means to upload a csv file which will be read by the R code. 2. A button to preprocess data (carried out by a R function behind) 3. A button to build some models
2011 Nov 10
2
Removing numbers from a list
I am using gsub to remove numbers for each element of a list. Code is given below. testList <- list("this contains a number 1000","this does not contain") removeNumbers <- function(X) { gsub("\\d","",X) } outputList <- lapply(testList,removeNumbers) However, when I try to find the number of words in outputList as follows
2012 Jul 20
3
Crosstab with Average and Count
I have the following data: x <- as.factor(c(1,1,1,2,2,2,3,3,3)) y <- as.factor(c(10,10,10,20,20,20,30,30,30)) z <- c(100,100,NA,200,200,200,300,300,300) I could create the cross tab of x and y with Sum of z as its elements using the xtabs function as follows: # X Vs. Y with Sum Z xtabs(z ~ x + y) y x 10 20 30 1 200 0 0 2 0 600 0 3 0 0 900 How do I replace
2012 Jul 09
4
Skipping lines and incomplete rows
I have a text file that has semi-colon separated values. The table is nearly 10,000 by 585. The files looks as follows: ******************************************* First line: Skip this line Second line: skip this line Third line: skip this line variable1 Variable2 Variable3 Variable4 Unit1 Unit2 Unit3 10 0.1 0.01 0.001 20
2011 May 31
2
Text Summarization
Is there a text mining/ NLP package in R that could do text summarization? For example, take a huge text as input and provide a summary of the text. In package tm, summarization is defined more as high frequency terms which is not what I want. I actually want a summary of what is present in the huge volume of text. Any help on a R package would be helpful. Thank you. Ravi -- View this message
2011 May 04
3
Error in .Fortran Call
I have the following FORTRAN code converted to a DLL: ! my_xmean.f90 ! ! FUNCTIONS/SUBROUTINES exported from my_function.dll: ! my_function - subroutine ! subroutine my_xmean(X,N,XMEAN) ! Expose subroutine my_function to users of this DLL ! !DEC$ ATTRIBUTES DLLEXPORT,C,REFERENCE,ALIAS:'my_xmean_'::my_xmean ! Body of my_function DOUBLE PRECISION X(N) XMEAN=0D0 DO J=1,N
2011 Aug 08
3
Distance between a vector and matrix rows
I am trying to find the distance between a vector and each row of a dataframe. I am using the function "distancevector" in the package "hopach" as follows: mydata<-as.data.frame(matrix(c(1,1,1,1,0,1,1,1,1,0),nrow=2)) V1 V2 V3 V4 V5 1 1 1 0 1 1 2 1 1 1 1 0 vec <- c(1,1,1,1,1) d2<-distancevector(mydata,vec,d="euclid") The Euclidean distance
2011 May 24
1
Fortran DLL in Spotfire
I have a R code that loads a FORTRAN DLL to do some calculations. The code works fine when I use it in R. But when I try it in spotfire it throws an error that the it is unable to load the shared library and the specified DLL cannot be found. I have used "setwd" to point to the location in the spotfire statistical services server library. Is this the correct way to call the DLL in
2011 Dec 06
1
HTML Forms to R
I have currently a R function that reads a csv file, does some computations, produces some plots and writes a csv file as output. I would like to use HTML forms to make a user interface for calling appropriate parts of the functions (reading csv file, doing computations, displaying plots and writing csv files). Are there are tutorials available that would help me get started?? Thank you. Ravi
2012 May 21
1
htmlParse Error
I am trying to parse a webpage using the htmlParse command in XML package as follows: library(XML) u = "http://en.wikipedia.org/wiki/World_population" doc = htmlParse(u) I get the following error: Error in htmlParse(u) : error in creating parser for http://en.wikipedia.org/wiki/World_population I am using a R 2.13.1 (32 bit version) on a 64 bit Windows. (I tried installing it in
2011 Apr 12
2
Optimzing a nested function
I am trying to optimize a nested function using nlminb. This throws out an error that y is missing. Can someone help me with the correct syntax?? Thank you. test1 <- function(x,y) { sum <- x + y return(sum) } test2 <- function(x,y) { sum <- test1(x,y) sumSq <- sum*sum return(sumSq) } nlminb(start = c(1,1), test2,lower = c(0,0), upper = c(5,5)) -- View this message in
2013 Apr 11
2
Creating a GUI based workflow
Hello R-users, I am interested to know if there is a tool that allows us to build SAS Enterprise Miner like workflows using the R scripts. For example, let's say I have the R scripts/functions for the following tasks: 1. Data Cleaning 2. Model Building 3. Model Validation 4. Visualization I would like to drag these functions into a workflow and run them together (output of one function
2011 May 09
5
Fortran Symbol Name not in Load Table
I am trying to call a FORTRAN subroutine from R. is.loaded is turning out to be TRUE. However when I run my .Fortran command I get the following error: Error in .Fortran("VALUEAHROPTIMIZE", as.double(ahrArray), as.double(kwArray), : Fortran symbol name "valueahroptimize" not in load table I have given the FORTRAN declaration below: subroutine VALUEAHROPTIMIZE(AHR,
2012 Jul 14
3
Can't understand syntax
...t and in newDf newDateTime is of class > POSIXct. > > Solution: > > [...] > df$dateTime <- strptime(df$dateTime,"%m/%d/%Y %H:%M") > df$dateTime <- as.POSIXct(df$dateTime) > [...] > > Hope this helps, > > Rui Barradas > > Em 13-07-2012 10:24, vioravis escreveu: > >> I have the following dataframe with the first column being of type >> datetime: >> >> dateTime <- c("10/01/2005 0:00", >> "10/01/2005 0:20", >> "10/01/2005 0:40", >>...
2011 Dec 06
1
Sequential Sum in R
I am trying to code the following excel formula in R. a b c Result Formula 1 10 0.1 #N/A IF(B2<20,NA(),C2+IF(ISERROR(D1),0,D1)) 2 20 0.2 0.2 IF(B3<20,NA(),C3+IF(ISERROR(D2),0,D2)) 3 30 0.3 0.5 IF(B4<20,NA(),C4+IF(ISERROR(D3),0,D3)) 4 40
2011 May 26
1
Using read.xls
I am using read.xls command from the gdata package. I get the following error when I try to read a work sheet from an excel sheet. Error in xls2sep(xls, sheet, verbose = verbose, ..., method = method, : Intermediate file 'C:\Tmp\RtmpYvLnAu\file7f06650f.csv' missing! In addition: Warning message: running command '"C:\Apps\Perl\bin\perl.exe" "C:/Program
2011 Sep 12
1
findFreqTerms vs minDocFreq in Package 'tm'
I am using 'tm' package for text mining and facing an issue with finding the frequently occuring terms. From the definition it appears that findFreqTerms and minDocFreq are equivalent commands and both tries to identify the documents with terms appearing more than a specified threshold. However, I am getting drastically different results with both. I have given the results from both the
2011 Sep 13
1
SVD Memory Issue
I am trying to perform Singular Value Decomposition (SVD) on a Term Document Matrix I created using the 'tm' package. Eventually I want to do a Latent Semantic Analysis (LSA). There are 5677 documents with 771 terms (the DTM is 771 x 5677). When I try to do the SVD, it runs out of memory. I am using a 12GB Dual core Machine with Windows XP and don't think I can increase the memory
2010 Oct 22
2
Random Forest AUC
Guys, I used Random Forest with a couple of data sets I had to predict for binary response. In all the cases, the AUC of the training set is coming to be 1. Is this always the case with random forests? Can someone please clarify this? I have given a simple example, first using logistic regression and then using random forests to explain the problem. AUC of the random forest is coming out to be