Equations that involve trigonometric functions can have infinitely many solutions. For example, the solution to the equation tan(θ)=1 is θ = π/4 + kπ, where k is any integer. In order to obtain a unique solution to the equation, we define the "arc" functions: inverse trigonometric functions that return a
When reading a text file (common extensions: TXT, DAT; or, for the adventurous: HTML) with the DATA STEP, you should always view several lines from the text file, and compare to the record layout, before completing the INPUT statement. There are many ways to view a text file. I use
I previously wrote about the best way to suppress output from SAS procedures. Suppressing output is necessary in simulation and bootstrap analyses, and it is useful in other contexts as well. In my previous article, I wrote, "many programmers use ODS _ALL_ CLOSE as a way to suppress output, but
Dataset too big for PROC PRINT? One weird trick solves your problem! proc print data=bigdata (obs=10); run; The OBS= dataset option specifies the last observation to process from an input dataset. In the above example, regardless of dataset size, only the first 10 observations are printed; an easy way to
Many of our authors often ask us where they can find real data that they can use without copyright or other confidentiality issues. Instructors too are always on the look-out for real-life data. Well, thanks to a new initiative supported by SAS, you can now access data from more than
New York City Mayor, Michael Bloomberg made a new-year's resolution to learn code. Apple’s Steve Jobs said, “I think everybody in this country should learn how to program a computer because it teaches you how to think.” President Barrack Obama said, "Don't just buy a new video game, make one.
I watched with wonder as each of my daughters learned how to "tell time." Early in their primary school careers, they brought home worksheets that featured clock faces with big-hand/little-hand configurations that they had to decipher, and exercises that asked them to draw the hands as they should appear given
So, how did you first learn SAS programming? Originally, I was self-taught. Many years ago, I learned SAS on the job when a systems programmer quit and I took over supporting a mainframe performance software package that was written in SAS. I got a copy of the Base SAS users
Most SAS programmers have been here. Someone just wants a handful of numbers that they can add to a graph or power point presentation that is due tomorrow. You have the data files, you have a job to summarize it, and you have a dilemma. How do I get my
Copy/paste is my favorite method for creating new SAS programs. In my work projects, I maintain a sort of genealogy of SAS programs, because the DNA of one program can be used to spawn many other SAS programs as its progeny. When things (inevitably) aren't working as I intend in
There's "big," and then there is "factorial big." If you have k items, the number of permutations is "k factorial," which is written as k!. The factorial function gets big fast. For example, the value of k! for several values of k is shown in the following table. You can
With any software program, there are always new tips and tricks to learn, and nobody can know them all. Sometimes I even pick up tips or techniques from my students while they’re learning broader programming tips from me. Like fine wine, instructors only get better with age. Every customer interaction
This article show how to run a SAS program in batch mode and send parameters into the program by specifying the parameters when you run SAS from a command line interface. This technique has many uses, one of which is to split a long-running SAS computation into a series of
SAS Global Forum brings together the most die-hard SAS users, both veteran and novice, once a year. It’s one of those can’t-miss events, and each year it just gets better. 2015 will bring us all together in Dallas, Texas for several days of active learning and excitement from SAS users
Back in the day when the prison system forced inmates to perform "hard labor", folks would say (of someone in prison): "He's busy making little ones out of big ones." This evokes the cliché image of inmates who are chained together, forced to swing a chisel to break large rocks
While perusing the SAS 9.4 DS2 documentation, I ran across the section on the HTTP package. This intrigued me because, as DS2 has no text file handling statements I assumed all hope of leveraging Internet-based APIs was lost. But even a Jedi is wrong now and then! And what better
SAS Enterprise Guide 7.1 began shipping last week. Of the many new features, some are "biggies" while others are more subtle. My favorite new features are those for SAS programmers, including several items that I've heard customers ask for specifically. I'll describe them briefly here; the SAS Enterprise Guide online
In response to my recent post about how to use the PALETTE function in SAS/IML to generate color ramps, a reader wrote the following: The PALETTE function returns an array of hexadecimal values such as CXF03B20. For those of us who think about colors as RGB values, is there an
When I create a graph of data that contains a categorical variable, I rarely want to display the categories in alphabetical order. For example, the box plot to the left is a plot of 10 standardized variables where the variables are ordered by their median value. The ordering makes it
We all know the importance of understanding the data you are working with. After all, the best programmers we know have combined their lifelong pursuit of programming knowledge with a similar pursuit of some specific subject matter. I have programmed in SAS for about 15 years and have pursued expertise
When you run a program or task in SAS Enterprise Guide, the application wraps your job in an "ODS sandwich", the colloquial term we use for the ODS statements necessary to create output that can be viewed in your project. That's convenient for exploring and refining your program, but at
These two tutorial videos will show you how to filter and sort data in Base SAS. In this first video, you will learn to use a WHERE statement in Base SAS to filter or subset SAS data. Data sets can be very large and filtering data enables you to select
My daughter's middle school math class recently reviewed how to compute the greatest common factor (GCF) and the least common multiple (LCM) of a set of integers. (The GCF is sometimes called the greatest common divisor, or GCD.) Both algorithms require factoring integers into a product of primes. While helping
Data cardinality is an important topic for for data analysis. In mathematical terms, cardinality is simply the number of elements in a set. But in data applications, cardinality signifies the number of unique values for a given field of data. Related terms include number of levels (thank you, PROC FREQ
Has this ever happened to you? You have a SAS program with statements that you wrote, then you make use of a macro function or %include file supplied by a helpful colleague, and when your SAS code resumes, you find that all of your SAS titles have been changed out
A couple of years ago I shared a method for copying any file within a SAS program. It was a simple approach, copying the file byte-by-byte from one fileref (SAS file reference) to another. My colleague Bruno Müller, a SAS trainer in Switzerland, has since provided a much more robust
Last week I presented two talks at the University of Wisconsin at Milwaukee, which has established a new Graduate Certificate in Applied Data Analysis Using SAS. While in Milwaukee, I ran into an old friend: the ODS LISTING destination. One of my presentations was a hands-on workshop titled Getting Started
Recently I wrote about how to determine the age of your SAS release. Experienced SAS programmers know that you can programatically determine information about your SAS release by using certain automatic macro variables that SAS provides: SYSVER: contains the major and minor version of the SAS release SYSVLONG: contains the
Even the best programmers make mistakes. For most errors, SAS software displays the nature and location of the error, returns control to the programmer, and awaits further instructions. However, there are a handful of insidious errors that cause SAS to think that a statement or program is not finished. For
In SAS 9.4, the SAS programming language continues add new features by the truckload. I've already discussed PROC DELETE (which is actually an old feature, but like an 80s hit song it's now back with a better version). In this SAS Tech Talk video from SAS Global Forum 2013, I
