sigmoid function

March 22, 2015 Leave a comment

What is a sigmoid function ?

It is http://mathworld.wolfram.com/SigmoidFunction.html

This simple code is the standard way to plot it. I am using Octave.

x = -10:0.1:10;
a = 1.0 ./ (1.0 + exp(-x));
figure;
plot(x,a,'-','linewidth',3)

sigmoid

Filed under Machine Learning, R

R wordcloud

March 22, 2015 Leave a comment

A piece of R code to beat the rut of my day job.

I have a document in the directory.

 transcript<-Corpus(DirSource("~/Documents/Algorithms/rcloud/"))
 transcript<-tm_map(transcript,stripWhitespace)
 transcript<-tm_map(transcript,tolower)
 transcript<-tm_map(transcript,stemDocument)
 transcript<-tm_map(transcript,PlainTextDocument)
 wordcloud(transcript,scale=c(5,0,5),max.words=100,random.order=FALSE,rot.per=0.35,use.r.layout=FALSE,colors=brewer.pal(8,"Dark2"))

wordcloud

Filed under R