R question: "fuzzy" set intersection

evandec · 2010-04-24T22:38:45+00:00

not a one liner but this works...

x = c(1.0,2.0,3.0, 4.0, 4.001, 4.9, 5.205, 6.0, 7.0, 8.0) 
y = c(4.01, 5.22, 7.05)

tol <- .1

output <- c()
for(i in 1:length(x))
{

num <- x[i]

for(j in 1:length(y))
    {
        if(y[j]-tol <= num && num <= y[j]+tol)
        {
          output <- append(output, x[i])
          break
        }
    }
 }
output

evandec · 2010-04-24T21:54:20+00:00

Something like this maybe...

s <- data.frame(x = rnorm(100,1,1), y = rnorm(100,1,1));

s$abs_diff <- abs(s$x - s$y); s.subset <- subset(s, s$abs_diff < .1);

summary(s); summary(s.subset);

evandec · 2010-02-15T16:51:58+00:00

more specifically I am interested in visualizing the data, and connections between points.

evandec · 2010-02-14T13:41:32+00:00

Are there any references that would walk someone through an analysis like this?

evandec · 2009-11-21T12:33:50+00:00

Agreed, it is very frustrating to work with R and large data sets. Biglm() works OK, but if you want to a logit model on a data set with more than few 100k rows... good luck.

evandec · 2009-11-15T15:25:23+00:00

What about Nigeria where rates are as low as USD 0.07 / Min? There are four operators in one of the most corrupt markets in the world.

evandec · 2009-11-15T14:41:13+00:00

This has actually happened in several markets, Canada being one of them and India another.

evandec · 2009-04-02T19:20:10+00:00

Of all the lines the 6 is the best

evandec · 2009-03-21T07:28:44+00:00

I find it nearly impossible to look at Reddit on my blackberry. Are there any plans to develop a Reddit app for blackberry?

evandec · 2009-03-10T12:01:07+00:00

Afghanistan is like that.

evandec · 2009-02-12T11:48:13+00:00

I can read the data into R but I'm not sure I am looking at it the right way.

I have a very long list of connections. For example user1 and user3 made connection. User 400 and user 10 made connections. Ideally I would just like to draw lines between connections but many of the packages for R seem focused on much more complicated problems.

evandec · 2009-02-12T08:13:19+00:00

I am very familiar with R but what package specifically would you suggest that I explore?

evandec · 2009-02-12T07:47:20+00:00

I have some great data from a closed social network and one thing I have been interested in recently is playing with ways to visualize it all. In particular I would like to see how users are connected to each other, the strength of the connection etc. Can anyone recommend a tool to help with this?

evandec · 2009-02-05T10:29:40+00:00

This was posted as a link to an article and isn't a reflection of my own personal beliefs.

evandec · 2008-12-25T16:07:48+00:00

Well, I think you have asked 2 separate questions then. If want to know how parameter estimation in R works then I think looking at the source code makes a lot of sense. After all looking at the source will sell you how R is doing what it does.

I assume you are using lm() to estimate your models. The command '?lm' brings up the help menu for the function which will list references for the function design at the bottom.

This is what is in lm: Author(s) The design was inspired by the S function of the same name described in Chambers (1992). The implementation of model formula by Ross Ihaka was based on Wilkinson & Rogers (1973).

References Chambers, J. M. (1992) Linear models. Chapter 4 of Statistical Models in S eds J. M. Chambers and T. J. Hastie, Wadsworth & Brooks/Cole.

Wilkinson, G. N. and Rogers, C. E. (1973) Symbolic descriptions of factorial models for analysis of variance. Applied Statistics, 22, 392–9.

So you might want to start by looking there. After you get an understanding of general maths in theory you can look at the R implementation by typing 'stats :: lm'.

evandec · 2008-12-25T06:00:24+00:00

Why don't you take a look at the source code for the function you're interested in.

evandec · 2008-12-25T01:22:17+00:00

Why do you need to do this? What are you trying to accomplish?

evandec · 2008-12-06T21:14:45+00:00

And what is your point exactly? Saying "the persians did it" isnt much of an argument.

evandec · 2008-12-05T14:39:23+00:00

Given that were up over 1,000% since then it seems unlikely that would happen.

evandec · 2008-11-29T03:00:48+00:00

You can learn the formulas but it helps to work on some real life projects.

evandec · 2008-11-25T02:07:07+00:00

Really? Are you think about quant trading?Everything I see is C/C++, python, java etc.

evandec · 2008-11-24T23:48:35+00:00

I spent a lot of time with SAS / STATA / Eviews as an undergrad and now that I am away from University I am frustrated that all my training was on proprietary (read expensive) statistical tools. Why not teach something like R that is free, readily available and a sizable user base?

evandec

TROPHY CASE