This week I had the opportunity to present a 1/2 day seminar on creating clinical graphs using the SG procedures during an In-House SAS Users' group meeting. I have presented this seminar quite a few times now, and I always learn something. The audience was very receptive, with some people
Have you ever wondered why sometimes a SGPLOT or GTL graph has markers drawn beyond the extreme tick and value on an axis and sometimes not? And, if you prefer your graphs to always have tick values on the axis that cover the whole range of data, how can you
In my article about how to create a quantile plot, I chose not to discuss a theoretical issue that occasionally occurs. The issue is that for discrete data (which includes rounded values), it might be impossible to use quantile values to split the data into k groups where each group
One of the key benefits of using a horizontal bar chart is the ability to display statistics for each bar. This is a popular feature for the HBAR statement with the SAS/GRAPH GCHART procedure. So, let us review the options available to us to create such graphs using SGPLOT. The
Heat maps are a great way to visualize the bi-variate distribution of data. Traditionally, a heat may may have two numeric variables, placed along the X and Y dimension. Each variable range is sub divided into equal size bins to create a rectangular grid of bins. The number of observations
What is kurtosis? What does negative or positive kurtosis mean, and why should you care? How do you compute kurtosis in SAS software? It is not clear from the definition of kurtosis what (if anything) kurtosis tells us about the shape of a distribution, or why kurtosis is relevant to
Getting consistent group colors across different data sets for a graph is a common topic of interest. Recently a user wrote in to ask how to ensure that specific groups "values" for a bar chart get specific colors. The group values may arrive in different order, or some may
Beginning with the first maintenance of SAS 9.4, you have the ability to define your own symbol markers using the SYMBOLCHAR and SYMBOLIMAGE statements. With these statements you can select a Unicode value or you can select an image file that exists on the local file system—making the possibilities for
The Mid-West SAS Users' Group conference in Chicago was a great success, with over 400 attendees and great weather. The conference hotel was in downtown with nice view of the river and a stroll down "Magnificent Mile". The city does a great job with the flower beds down Michigan Ave., along
A HighLow plot is very popular in the financial industry, often used to track the periodic movement of a stock or some instrument or commodity. The CandleStick Chart is one specific type of high low plot, purportedly originating in Japan for tracking of financial instruments in the rice trade. Creating a
While at JSM 2014 in Boston, a statistician asked me whether it was possible to create a "customized bin plot" in SAS. When I asked for more information, she told me that she has a large data set. She wants to visualize the data, but a scatter plot is not
Many users of SGPLOT and GTL know how to mix and match various plot statements to create graphs, sometimes in ways not originally intended. You are also aware that you can go a step beyond, and use these systems to create completely non-standard graphs such as the Spiral Plot, the Polar
It's time for another blog post about ciphers. As I indicated in my previous blog post about substitution ciphers, the classical substitution cipher is no longer used to encrypt ultra-secret messages because the enciphered text is prone to a type of statistical attack known as frequency analysis. At the root
The Third PharmaSUG-China conference was held in Beijing last week, and I had the pleasure to attend this excellent conference along with a record number of attendees. On Thursday, I presented two 1/2 day seminars on ODS Graphics. One titled "Advanced Topics in GTL" and another titled "Complex Clinical Graphs
Often we need to plot the response values for binary cases of a classifier. The graph below is created to simulate one seen at http://www.people.vcu.edu/ web site of the shock index for subjects with or without a pulmonary embolism. In this case, the data is simulated for illustration purposes only. There
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
While I was working on my recent blog post about two-dimensional binning, a colleague asked whether I would be discussing "the new hexagonal binning method that was added to the SURVEYREG procedure in SAS/STAT 13.2." I was intrigued: I was not aware that hexagonal binning had been added to a
The ODS ExcelXP tagset has served us well over the years. It provides a reliable method to get formatted SAS output into Microsoft Excel workbooks, where the business world seems to like to live. And it's available in Base SAS, which means that you don't need SAS/ACCESS to PC Files
When you create a histogram with statistical software, the software uses the data (including the sample size) to automatically choose the width and location of the histogram bins. The resulting histogram is an attempt to balance statistical considerations, such as estimating the underlying density, and "human considerations," such as choosing
SAS 9.4 maintenance release M2 was released early in August. This release contains some exciting new features in GTL and SG Procedures. In this article, I will describe some of the new options added to the existing plot statements. Note, I will use the SG examples here, but these are
Often there are questions from users on creating histogram using a Log X axis. One such question came up this weekend, where a user wanted a histogram of her data using log axis. Before we get into her specific case, let us first clarify what we may want to see
In her article Creating Spaghetti Plots Just got Easy, Lelia McConnell has provided us a glimpse into some new useful features in the SAS 9.4M2 release. The term Spaghetti plots generally refers to cases where time series plots have to be identified by multiple group classifications. The support for the
This article is by guest contributor Lelia McConnell, SAS Tech Support. Creating Spaghetti Plots Just Got Easy Sample 38076: “Response by patient and treatment group” illustrates how to generate a spaghetti plot using the SGPLOT procedure. Sample 40255: “Plot of study results by treatment group” illustrates how to generate a
A couple of days back, Rick Wicklin forwarded me a link to an article on the BadHessian Blog on creating a Bar Chart using six different freeware packages in R, Python and Julia. The target bar chart was one produced by the Jetpack stat module with WordPress. The graph is shown below. The unique feature of
In a previous blog post, I showed how to overlay a prediction ellipse on a scatter plot in SAS by using the ELLIPSE statement in PROC SGPLOT. The ELLIPSE statement draws the ellipse by using a standard technique that assumes the sample is bivariate normal. Today's article describes the technique
This post could be titled something like "Everything you wanted to know about Group Order in GTL - and more." The group ordering shows up in three different ways in your graph. Assignment of attributes (color, marker symbol) to group values. Position of group values in the graph. Display of the group
It is common in statistical graphics to overlay a prediction ellipse on a scatter plot. This article describes two easy ways to overlay prediction ellipses on a scatter plot by using SAS software. It also describes how to overlay multiple prediction ellipses for subpopulations. What is a prediction ellipse? A
In my four years of blogging, the post that has generated the most comments is "How to handle negative values in log transformations." Many people have written to describe data that contain negative values and to ask for advice about how to log-transform the data. Today I describe a transformation
In my previous blog post, I showed how to use log axes on a scatter plot in SAS to better visualize data that range over several orders of magnitude. Because the data contained counts (some of which were zero), I used a custom transformation x → log10(x+1) to visualize the
If you are trying to visualize numerical data that range over several magnitudes, conventional wisdom says that a log transformation of the data can often result in a better visualization. This article shows several ways to create a scatter plot with logarithmic axes in SAS and discusses some of the
