In my article about finding an initial guess for root-finding algorithms, I stated that Newton's root-finding method "might not converge or might converge to a root that is far away from the root that you wanted to find." A reader wanted more information about that statement. I have previously shown
The SGPLOT procedures includes features to add annotations to your graph in many different ways. Annotations provide you a flexible way to add features to your graph that are not available through the standard plot statements. Recently, I saw this graph on the web that caught my attention. Clearly, this looks like
I still remember the first time I was asked to "consult" on a statistical problem. A former physics professor had some students who had gathered data that should lie along an arc of a theoretical circle. The professor asked if there was a regression technique that could find the center
I was reading a statistics book when I encountered a histogram that caught my eye. The histogram looked similar to the one at the left. It contained a normal density estimate overlaid on a histogram, but the height of the density curve seemed too short when compared to the heights
If you have programmed with SAS in the last 15 years, you have probably had a reason to share your SAS results in PDF format. The ODS PDF destination, much like a well-designed car, has evolved over the years, offering progressively nicer features like security, enhanced image formatting and embedded
When I was an undergraduate physic major, my favorite professor would start each class with a joke or pun. One day he began class with a paraphrase of a famous quote from the movie Star Trek 4: The Voyage Home (the one with the whales). "Today," my professor said, imitating
North Carolina is a state that requires yearly inspections of motor vehicles. An inspection checks for safety features (lights, brakes, tires,....) as well as checking vehicle emissions to ensure that vehicles meet air pollution standards. I recently had a car inspected and noticed a pie chart on the inspection's summary
SGF 2015 was a blast with a focus on Visual Analytics, SAS Studio, Hadoop and more. Graphs were everywhere, and it was a banner year for ODS Graphics with over 15 papers and presentations by users on creating graphs using SG Procedures, GTL and Designer. Dan Heath, Prashant Hebbar, Scott
Did you know that if you have set multiple titles in SAS, that there is an easy way to remove them? For example, suppose that you've written the following statements, which call the TITLE statement to set three titles: title "A Great Big Papa Title"; title2 "A Medium-sized Mama Title";
Sometimes different communities use the same name for different objects. To a soldier, "boots" are rugged, heavy, high-top foot coverings. To a soccer (football) player, "boots" are lightweight cleats. So it is with the term "waterfall plot." To researchers in the medical field, a "waterfall plot" is a sorted bar
A very common type of graph contains two series plot, where the user is expected to evaluate the difference visually. I saw one such plot on the web today shown on the right. This graph has two curves, one for malpractice premiums and one for claims, with a shaded band
In clinical trials, a waterfall plot is often used to indicate how patients in the study responded to treatment. In oncology trials, the response variable might be the percent change in the size of a tumor from the individual's baseline value at the start of the trial. The percent change
MicroMaps are a powerful way to display data where the display includes small, lightweight maps to provide geographical information regarding the data. This geographical information gives clues to the relationship between the data that could lead to more insight. The SAS SG Procedures and GTL do not currently have built-in
Last week I was chatting with some mathematicians and I mentioned the blog post that I wrote last year on the distribution of Pythagorean triples. In my previous article, I showed that there is an algorithm that uses matrix multiplication to generate every primitive Pythagorean triple by starting with the
Back in late 2012 I discussed a technique for Conditional Highlighting, where additional attributes can be displayed in a graph. In the previous article the goal was to display a graph of Response by Year by Drug. We used a cluster grouped bar chart to create the bar chart. We
In the traveling salesman problem (TSP), a salesman must minimize travel distance while visiting each of a given set of cities exactly once. Recently, the TSP has generated some buzz in the popular media, after a blog post by Randy Olson. The tour shown was not quite optimal, and Bill
Sankey Diagrams have found increasing favor for visualization of data. This visualization tool has been around for a long time, traditionally used to visualize the flow of energy, or materials. . Now to be sure, GTL does have a statement design for a Sankey Diagram which was implemented only in Flex for use
In the previous article, I described the process to create a 3D Scatter Plot using a 3D Orthographic View matrix and the SGPLOT procedure. I posted a macro that can be used to create a 3D scatter plot from any SAS data set, using 3 numeric columns, one each for
Saturday, March 14, 2015, is Pi Day, and this year is a super-special Pi Day! This is your once-in-a-lifetime chance to celebrate the first 10 digits of pi (π) by doing something special on 3/14/15 at 9:26:53. Apologies to my European friends, but Pi Day requires that you represent dates
The SG Procedures do not support creating a 3D scatter plot. GTL has some support for 3D graphs, including a 3D Bi-variate Histogram and a 3D Surface, but still no 3D point cloud. The lack of such a feature is not due to any difficulty in doing this as
Data. To a statistician, data are the observed values. To a SAS programmer, analyzing data requires knowledge of the values and how the data are arranged in a data set. Sometimes the data are in a "wide form" in which there are many variables. However, to perform a certain analysis
Last week a user wanted to view the distribution of data using a Box Plot. The issue was the presence of a lot of "bad" data. I got to thinking of ways such data can be visualized. I also discussed the matter with our resident expert Rick Wicklin who pointed
The xkcd comic often makes me think and laugh. The comic features physics, math, and statistics among its topics. Many years ago, the comic showed a "binary heart": a grid of binary (0/1) numbers with the certain numbers colored red so that they formed a heart. Some years later, I
Significant progress in reduction of Cancer mortality is shown in a graph that I noticed recently on the Cancer Network web site. This graph showed the actual and projected cancer mortality by year for males. The graph is shown on the right. The graph plots the projected and actual numbers
Including special Unicode symbols into the graph is getting more popular. In general, SG procedures support Unicode strings in places where these strings are coded into the syntax such as TITLE, FOOTNOTE. These support Unicode characters and also the special {SUP} and {SUB} commands. This is because these statements are rendered
There has been much discussion on the SAS Communities page on usage of different symbols in a graph. The solutioin can vary based on the SAS release. New features have been added at SAS 9.4 releases to SG Procedures and GTL that make this very easy. With SAS 9.4M1, almost any combination is
Over the Christmas Holidays I saw an graph of agricultural exports to Russia in 2013. The part that caught my eye was the upper part of the graph, showing the breakdown of the trade with Russia as a horizontal stacked bar with custom labels. The value for each region / country
I published 118 blog posts in 2014. This article presents my most popular posts from 2014 and late 2013. 2014 will always be a special year for me because it was the year that the SAS University Edition was launched. The University Edition means that SAS/IML is available to all
Last week a user expressed the need to create a graph like the one shown on the right using SAS. This seems eminently doable using GTL and I thought I would undertake making this graph using SAS 9.3. The source data required to create this graph is only the
If you haven’t tried them for your web applications and other graphics needs, you’ll want to read further! Scalable Vector Graphics (SVG) output is vector graphics output you can display with most (if not all) modern web browsers. Because SVG graphic output is scalable, you can zoom in on the
