Eviews is one of the popular econometrics packages being used by research community and academicians. It is a GUI (Graphical User Interface) based program compatible with Windows and Macintosh operating systems. Other popular econometrics packages include, SHAZAM, LIMDEP, SAS and GAUSS etc. Eviews is one of the most popular software for analyzing time series data. Eviews, produced by Quantitative Micro Software (QMS) from Irvine, California, comes with very useful user guide and reference manuals called, The Users Guide and The Command and Programming Reference (www.eviews.com). If you are familiar with programs like C++ and Gauss you will be able to use your programming skills to run your own customized protocols in Eviews. Let us view some examples of Eviews code here.
Autocorrelation in GAM and GRASP models is an important topic of discussion since these models are being widely used in predictive animal and plant distribution models in the discipline of ecology.
The most widely used statistical models in the fields of ecological modeling, biodiversity and conservation are Generalized Linear Models (GLM) and GAM (General Additive Model) which is a semi-parametric extension of GLM. GRASP stands for Generalized Regression Analysis and Spatial Prediction (http://www.cscf.ch/grasp/grasp-s/welcome.html). GRASP is a combination of advanced S Plus functions and GIS (Geographical Information System) Many of these applications can be run through the software “R” (www.r-project.org).
What is Autocorrelation?
Autocorrelation describes correlation between a process, say Xt, at a different point of time Xs. The autocorrelation function can be depicted in a formula as
where Xt has the variance σ2 and mean μ. E is the expected value. The result will range between -1 and 1. 1 indicates perfect correlation while -1 indicates perfect anti-correlation. You must note that the function should be well defined.
Before launching into a controversial topic, it is a good idea to get the definition of terms straight, so I put together a glossary of forms of content found on the web. By no means complete, please feel free to add more.
In the field of biomedical research, people are often excited when the results of their research are controversial. However, it evoked limited attention when Cell, a scientific journal in the US, recently reported that some Japanese scientists at Kyoto University claimed that four genes or factors transformed mouse cells to act like ESCs (Ethical Embryonic Stem Cells). However, a lot of excitement was created recently when the US, Massachusetts-based, Advanced Cell Research (ATC), said that it has created ESCs without destroying the embryos, as this would seem to remove the principal objection to stem-cell research.
When you deal with spreadsheets like Microsoft Excel, circularities or circular references may lead to significant problems. Circularities in spreadsheets occur when one code requires information from another code, which requires the information from the first code. Patrick Burns, in his article on ‘Spreadsheet Addiction’ says that the spreadsheets that are available today, including Microsoft Excel and Works, have limitations in terms of operational risks. He goes on to say that some of the spreadsheets in the market available today will go obsolete due to lack of Sarbanes-Oxley compliance.
Many vendors, such as Spreadsheet Advantage (www.Spreadsheetadvantage.com), are there to help you deal with circularity in spreadsheets. Since you have to calculate iteratively when you deal with a spreadsheet with circularities, you might witness higher recalculation time, sometimes ending up with incorrect solutions.
If you are dealing with a large spreadsheet, tracking down all the circularities would be a tedious task. Custom-built software solutions to track down circularities is able to fetch you the circularities in minimal time. All you need to do is submit your spreadsheet containing circularities to the circularity finding software and the software will generate a list of all the circularities in your spreadsheet. Software solutions from vendors such as Advantage for Analysts (www.advantageforanalysts.com) include capabilities like handling circularities in spreadsheets, goal-seeking and optimization.
Back after summer break, and deeply involved in a new project to apply niche modeling to business analytics in a completely novel way.
One of the main problems confronting new business owners is defining their market niche. A market niche is a bit like art, you know it when you see it, that is, when you are making a profit. But experimenting with product lines in conventional markets can be time consuming and expensive.
However, the Internet is a whole new world. Instant feedback from customers is possible, and can potentially be used to adjust and refine and optimize your business. Business entities and technologies are becoming an ecosystem in themselves. Niche theory provides a way of looking at it.
A new site called HitTail filters the massive amount of information from hits on your site due to natural search into a list of keywords called ’suggestion’. These keywords can be used in a number of profitable ways. For example, GaryTheScubaGuy used these unique keywords in Adwords advertising campaigns to greatly reduce costs and increase the effectiveness.
… now my top 10 keywords on this campaign are #1 and I am spending 36% less than I was 3 months ago to be there.
The approach of my business analytics project is guiding and shaping a website or online business into a more profitable niche, a process I describe in the post What is NicheShaping About?. The theory is that using suggestions from HitTail to create novel content will inevitably give more hits on subject matter more relevant to more people. Ideally, the process discovers natural niche markets, and eventually produces total dominance — just like natural ecological processes.
