Generate a series of column names in R

#if you want a series of column names, e.g., col1,col2,col3, ..., #you can use: mydf<-data.frame(matrix(ncol=5,nrow=4)) colnames(mydf)<-c("col1","col2","col3","col4","col5") #Well, it does work, but how about for 50 columns? #A loop! Sounds great. Okay, mydf<-data.frame(matrix(ncol=50,nrow=4)) for (n in 1:ncol(mydf)) {       colnames(mydf)[n]<-paste("col",n,sep="") } #But again, it's as urgly as the textbook. Here we offer a much better solution: colnames(mydf)<-paste(rep("col",ncol(mydf)),c(1:ncol(mydf)),sep="") #Smart, eh? At least the nicer looking :) #From http://scriptdemo.blogspot.com

Trim a string in R

# sub-functions # Copyright: http://scriptdemo.blogspot.com mytrim<-function(oristr) {      oristr<-sub("^ +","",oristr)      oristr<-sub(" +$","",oristr)      # or gsub("(^ +)|( +$)","",oristr)      return(oristr) }

Run matlab m-file in a shell script

It is common to run Matlab without splash and desktop using the following command,         matlab -nosplash -nodesktop Sometime the "-nojvm" option also help to reduce the memory requires if the java-virtual-mathine features are not necessary in your script. But, what should we do if we want to run a Matlab m-file in a shell script? The only thing we need is the option of "-r",         matlab -nosplash -nodesktop -r YourMFile However, sometimes it will be much more convenient if we can run the function-type m-file with arguments. Here it comes today's tricky stuff:                matlab -nodesktop -nosplash -r YourMFile\(Number,\'character\'\) Matlab Start Help

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Here is an example,
runMatlabScript.sh

#!/bin/bash myNum=30 myT="Demo\ of\ Peaks\(${myNum}\)" myPNG="fig_peaks_${myNum}" eval "/media/SW_Preload/matlab/bin/matlab -nodesktop -nosplash -r showPeaks\(${myNum},\'${myT}\',\'${myPNG}\'\)"

showPeaks.m:

function showPeaks(myN,myTitle,myPNG) % show the the peaks % usage: %           showPeaks(N,Title,FileName) %           http://scriptdemo.blogspot.ca if nargin~=3    disp('Usage: ')    disp(' showPeaks(N,Title,FileName) ')    return end hf=figure('visible','off'); set(hf,'color','w','render','zbuffer'); hp=pcolor(peaks(myN)); set(hp,'linestyle','none'); title(myTitle,'fontweight','bold','fontsize',16); set(gca,'linewidth',2) eval(['print -dpng -r300 ',myPNG,'.png']) close; exit