Today we will be finally creating our long awaited GDP forecast. In order to create this forecast we have to combine both the forecast from our deterministic trend model and the forecast from our de-trended GDP model. Our model for the trend is:t...
Monthly Archives: September 2011
Scatter plots with images
Edward Tufte has written extensively on the presentation of data covering good and bad practice. He has made a number of suggestions for adaptations of regularly used graph types to assist with the interpretation and understanding of data. One idea for enhancing scatter plots covered in Tufte’s book Beautiful Evidence is the use of images
Microfinance in India: Getting a sense of the geographic distribution
I am working on a review paper on microfinance in India and use data from the MIX market. Today, I was amazed by how quick I conjured a map of India with the headquarters of the microfinance institutions that report data to the MIX market depicted on that map. Ideally, I would have more geolocation
The Problems with Pairing R + Java
A core focus of the RTextTools project has been to make the package as accessible and user-friendly as possible. In its early iterations, the package contained dependencies such as RWeka, openNLP, and
An example of ROC curves plotting with ROCR
Decided to start githib with ROC curve plotting example. There is not a one ROC curve but several - according to the number of comparisons (classifications), also legend with maximal and minimal ROC AUC are added to the plot. ROC curves and ROC AU...
rmongodb – R Driver for MongoDB
The source code to rmongodb (home page at http://cnub.org/rmongodb.ashx), a driver to MongoDB for the R language, has been released as open source at GitHub: https://github.com/gerald-lindsly/rmongodb. This portable full-featured package was developed on top of the mongodb.org supported C driver. It runs almost entirely in native code so you can expect high performance. Plans are to submit rmongodb to CRAN soon for pre-built binary distribution, but first I would...
A quick way to do row repeat and col repeat (rep.row, rep.col)
Today I worked on a simulation program which require me to create a matrix by repeating the vector n times (both by row and by col). Even the task is extremely simple and only take 1 line to finish(10sec), I have to think about should the argument in rep be each or times and should 
Discussion thread on R vs SAS for businesses
There's an interesting discussion thread on LinkedIn going on now on the relative benefits of R versus SAS in the commercial sector. Oleg Okun kicks off the discussion with this question: Did anyone have to justify to a prospect/customer why R is better than SAS? What arguments did you provide? Did your prospect/customer agree with them? Why do you...
Assessing the Forecasting Ability of Our Model
Today we wish to see how our model would have faired forecasting the past 20 values of GDP. Why? Well ask yourself this: How can you know where your going, if you don't know where you've been? Once you understand please proceed on with the following post.
First recall the trend portion that we have already accounted for:
> t=(1:258)
> t2=t^2
> trendy= 892.656210 +...
Part 2 of 3: Non-linear Optimization of Predictive Models with R
In my previous post, I was able to build a predictive model (simple linear model) to predict the gross margin % of an eCommerce site based on the promotional spend accross various paid channels. I repeated the process for AOV (average order ...
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
