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Advanced Analytics | Learn SAS

Rick WicklinFebruary 19, 2014 0

Techniques for scoring a regression model in SAS

My previous post described how to use the "missing response trick" to score a regression model. As I said in that article, there are other ways to score a regression model. This article describes using the SCORE procedure, a SCORE statement, the relatively new PLM procedure, and the CODE statement.

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Advanced Analytics | Learn SAS

Rick WicklinFebruary 17, 2014 0

The missing value trick for scoring a regression model

A fundamental operation in statistical data analysis is to fit a statistical regression model on one set of data and then evaluate the model on another set of data. The act of evaluating the model on the second set of data is called scoring. One of first "tricks" that I

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Advanced Analytics | Data Management | Data Visualization

David PopeFebruary 15, 2014 0

Does the architecture matter as much as the analytics?

I was recently part of team discussing enterprise architecture with a chief IT architect, and we were explaining how SAS can integrate into their existing infrastructure, add business value on top it and even fit into their future planned infrastructure. This conversation was one of the reasons I blogged about

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Advanced Analytics | SAS Events | Students & Educators

Polly Mitchell-GuthrieFebruary 7, 2014 0

Skills needed for competitive advantage in analytics (hint, it's not just the math)

I'm a big believer in both/and thinking, so I'll stand squarely in the middle and say that the most important skills for competitive advantage in analytics include a combination of top-notch modeling abilities along with business acumen, critical thinking, and curiosity. I was intrigued by a blog post on this

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Advanced Analytics

Kenneth SanfordJanuary 28, 2014 0

Using panel data to measure the economic impact of the Super Bowl

This year the Super Bowl will take place in East Rutherford, New Jersey at MetLife Stadium just outside New York City. For the first time in this event’s 48-year history, the game will take place outdoors in a cold-weather environment, potentially subjecting players and fans to sub-freezing temperatures. The fans

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Advanced Analytics

Rick WicklinJanuary 21, 2014 0

The best articles of 2013: Twelve posts from The DO Loop that merit a second look

I began 2014 by compiling a list of 13 popular articles from my blog in 2013. Although this "People's Choice" list contains many articles that I am proud of, it did not include all of my favorites, so I decided to compile an "Editor's Choice" list. The blog posts on

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Advanced Analytics

Rick WicklinJanuary 7, 2014 0

13 popular articles from 2013

In 2013 I published 110 blog posts. Some of these articles were more popular than others, often because they were linked to from a SAS newsletter such as the SAS Statistics and Operations Research News. In no particular order, here are some of my most popular posts from 2013, organized

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Advanced Analytics

Rick WicklinDecember 4, 2013 0

Secret Santa: What is the probability that someone pulls her own name from a hat?

Each year my siblings choose names for a Christmas gift exchange. It is not unusual for a sibling to pick her own name, whereupon the name is replaced into the hat and a new name is drawn. In fact, that "glitch" in the drawing process was a motivation for me

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Advanced Analytics

Gerhard SvolbaDecember 3, 2013 0

"The hungry statistician" – or why we never can get enough data

As the “Year of Statistics” comes to a close, I write this blog in support of the many statisticians who carefully fulfil their analysis tasks day by day, and to defend what may appear to be demanding behavior when it comes to data requirements. How do statisticians get this reputation? Are we

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Advanced Analytics

Rick WicklinNovember 25, 2013 0

Twelve advantages to calling R from the SAS/IML language

For several years, there has been interest in calling R from SAS software, primarily because of the large number of special-purpose R packages. The ability to call R from SAS has been available in SAS/IML since 2009. Previous blog posts about R include a video on how to call R

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Advanced Analytics

Juthika KharghariaNovember 22, 2013 0

How WAVELETS can help separate the signal from the noise

Wavelet analysis is an exciting and relatively new field of study that enables one to extract underlying patterns either from spatially varying or temporally varying data. Pixel values representing the relative brightness and color that constitute an image are an example of spatially varying data, and daily variations of financial

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Advanced Analytics

Rick WicklinNovember 20, 2013 0

Write a reusable SAS/IML module that passes values to R

When I call R from within the SAS/IML language, I often pass parameters from SAS into R. This feature enables me to write general-purpose, reusable, modules that can analyze data from many different data sets. I've previously blogged about how to pass values to SAS procedures from PROC IML by

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Advanced Analytics | SAS Events | Students & Educators

Jerry OglesbyOctober 18, 2013 0

ANALYTICS 2013 – A BEST PRACTICE CONFERENCE FOR ANALYTICS PROFESSIONALS

We are in the final countdown to the Analytics 2013 Conference to be held next week, October 21-22 at the Hyatt Regency Orlando. There is a power-packed agenda for the conference, featuring four very strong keynote presentations from Dr. Jim Goodnight, CEO of SAS; Ed Gaffin, Walt Disney World; Will Hakes,

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Advanced Analytics

Gerhard SvolbaOctober 13, 2013 0

Why my aunt Susanne and her friends give us a hard time in statistical analysis

My aunt Susanne is an elderly lady, who lives at the countryside and looks forward to celebrating her 80th birthday soon. Since the 1960's she has had a telephone connection with her fixed line provider. At that time, and for many years later, in the country where my aunt lives,

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Advanced Analytics | Learn SAS

Rick WicklinSeptember 30, 2013 0

Generate combinations in SAS

Last week I described how to generate permutations in SAS. A related concept is the "combination." In probability and statistics, a combination is a subset of k items chosen from a set that contains N items. Order does not matter, so although the ordered triplets (B, A, C) and (C,

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Advanced Analytics

Patrick MaherSeptember 27, 2013 0

The truth about the big data evolution (or at least as I see it)

Some recent press articles question the value of big data while a book takes the opposite approach; I’ll choose the middle way. The New York Times article ‘Is Big Data an Economic Big Dud?’ questions the value of digital data and the resulting increase in the amount of data. This

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Advanced Analytics

Rick WicklinSeptember 25, 2013 0

Compute contours of the bivariate normal CDF

This is the last post in my recent series of articles on computing contours in SAS. Last month a SAS customer asked how to compute the contours of the bivariate normal cumulative distribution function (CDF). Answering that question in a single blog post would have resulted in a long article,

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Advanced Analytics | Learn SAS

Rick WicklinSeptember 23, 2013 0

Generate permutations in SAS

I've written several articles that show how to generate permutations in SAS. In the SAS DATA step, you can use the ALLPEM subroutine to generate all permutations of a DATA step array that contain a small number (18 or fewer) elements. In addition, the PLAN procedure enables you to generate

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Advanced Analytics

Rick WicklinJuly 26, 2013 0

How to choose parameters so that a distribution has a specified mean and variance

The truncated normal distribution TN(μ, σ, a, b) is the distribution of a normal random variable with mean μ and standard deviation σ that is truncated on the interval [a, b]. I previously blogged about how to implement the truncated normal distribution in SAS. A friend wanted to simulate data

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Advanced Analytics

Juthika KharghariaJuly 12, 2013 0

How incremental response modeling can help you reach the right target group more precisely

Did you know that more than 30,000 Americans die in traffic accidents every year? Interestingly, the U.S. import of mangoes from Brazil is found to be highly correlated with this fatality rate, as shown in the graph below. But are mango imports a good indicator of the future traffic fatality

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Advanced Analytics

Rick WicklinJune 24, 2013 0

Count the number of unique rows in a matrix

How do you count the number of unique rows in a matrix? The simplest algorithm is to sort the data and then iterate down the rows, comparing each row with the previous row. However, this algorithm has two shortcomings: it physically sorts the data (which means that the original locations

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Advanced Analytics

Rick WicklinJune 5, 2013 0

Using simulation to compute a power curve

Last week I showed how to use simulation to estimate the power of a statistical test. I used the two-sample t test to illustrate the technique. In my example, the difference between the means of two groups was 1.2, and the simulation estimated a probability of 0.72 that the t

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Advanced Analytics

Rick WicklinMay 30, 2013 0

Using simulation to estimate the power of a statistical test

The power of a statistical test measures the test's ability to detect a specific alternate hypothesis. For example, educational researchers might want to compare the mean scores of boys and girls on a standardized test. They plan to use the well-known two-sample t test. The null hypothesis is that the

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Advanced Analytics

Rick WicklinApril 29, 2013 0

Understanding local and global variables in the SAS/IML language

The TV show Cheers was set in a bar "where everybody knows your name." Global knowledge of a name is appealing for a neighborhood pub, but not for a programming language. Most programming languages enable you to define functions that have local variables: variables whose names are known only inside

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Advanced Analytics

Rick WicklinApril 24, 2013 0

How to overlay a custom density curve on a histogram in SAS

I've previously described how to overlay two or more density curves on a single plot. I've also written about how to use PROC SGPLOT to overlay custom curves on a graph. This article describes how to overlay a density curve on a histogram. For common distributions, you can overlay a

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Advanced Analytics

Rick WicklinApril 8, 2013 0

Point/Counterpoint: Where should you put ODS SELECT and ODS OUTPUT statements?

ODS statements are global SAS statements. As such, you can put them anywhere in your SAS program. For maximum readability, many SAS programmers agree that most ODS statements should appear outside procedures in "open" SAS code. For example, most programmers agree that the following statements should appear outside of procedures:

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Advanced Analytics

Gerhard SvolbaMarch 28, 2013 0

Dear Ms. Value! I am missing you! - or the importance of missing values in analytics

Don’t worry! This is not an excerpt from a romantic love letter. The title of this blog post is an allusion to my talk on "Missing Values", at the A2013 conference in June in London. There is not much time for emotions: dealing with missing values in analysis is not

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Advanced Analytics

Rick WicklinMarch 27, 2013 0

How to compute the distance between observations in SAS

In statistics, distances between observations are used to form clusters, to identify outliers, and to estimate distributions. Distances are used in spatial statistics and in other application areas. There are many ways to define the distance between observations. I have previously written an article that explains Mahalanobis distance, which is

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Advanced Analytics

Rick WicklinMarch 20, 2013 0

Understanding ridge regression in SAS

Someone recently asked a question on the SAS Support Communities about estimating parameters in ridge regression. I answered the question by pointing to a matrix formula in the SAS documentation. One of the advantages of the SAS/IML language is that you can implement matrix formulas in a natural way. The

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Advanced Analytics

Dan KellyMarch 13, 2013 0

Hungry dogs and decision-making under uncertainty

My wife rescued a dog a couple of years ago from a rural North Carolina rest stop . We named her "DOTi" in honor of the Department of Transportation. It took a while for us to get into the swing of being responsible owners; sometimes the first to leave for

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