## Tag: Statistical Graphics

2
Top posts from The DO Loop in 2020

Last year, I wrote more than 100 posts for The DO Loop blog. In previous years, the most popular articles were about SAS programming tips, statistical analysis, and data visualization. But not in 2020. In 2020, when the world was ravaged by the coronavirus pandemic, the most-read articles were related

2
Decile plots in SAS

I previously showed how to create a decile calibration plot for a logistic regression model in SAS. A decile calibration plot (or "decile plot," for short) is used in some fields to visualize agreement between the data and a regression model. It can be used to diagnose an incorrectly specified

0
Three tips for plotting discontinuous functions in SAS

I have previously written about how to plot a discontinuous function in SAS. That article shows how to use the GROUP= option on the SERIES statement to graph a discontinuous function. An alternative approach is to place a missing value for the Y variable at the locations at which the

2
Automate the placement of reference lines in PROC SGPLOT

The REFLINE statement in PROC SGPLOT is one of my favorite ways to augment statistical graphics such as scatter plots, series plots, and histograms. The REFLINE statement overlays a vertical or horizontal reference line on a graph. You can specify the location of the reference lines on the REFLINE statement.

0
Generate random points in a polygon

The triangulation theorem for polygons says that every simple polygon can be triangulated. In fact, if the polygon has V vertices, you can decompose it into V-2 non-overlapping triangles. In this article, a "polygon" always means a simple polygon. Also, a "random point" means one that is drawn at random

1
Visualize uncertainty in regression predictions

You've probably seen many graphs that are similar to the one at the right. This plot shows a regression line overlaid on a scatter plot of some data. Given a value for the independent variable (x), the regression line gives the best prediction for the mean of the response variable

Programming Tips
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The HighLow plot: When a stacked bar chart is not enough

The HighLow plot often enables you to create many custom plots without resorting to annotation. Although it is designed to create a candlestick chart for stocks, it is incredibly versatile. Recently, a SAS programmer wanted to create a patient-profile graph that looked like a stacked bar chart but had repeated

0
Visualize the structure of a sparse matrix

Sometimes in matrix computations, it is important to display the nonzero elements of a matrix. This can be useful for visualizing the structure of a sparse matrix (one that has many zeros) and it is also useful when describing a matrix algorithm (such as Gaussian elimination) that introduces zeros at