Category Archives: Chart Principles

Basic principles for effective charts, drawing on guidance from Tufte, Cleveland, Robbins, Few.

Temperature Anomaly Data Displays

Is there a single “best” way to display temperature anomaly data? The answer is obvious – NO! The best display depends on what we are trying to show.  Statistical charts compare one variable with one or more other variables.

Since our display option affects how we interpret the data, it is important to be clear on what we are comparing. In this post I want to show 3 ways to display temperature anomaly data and the implications that the display method has on our interpretation of the data. I’ll use a map, a trend chart and a dot plot. Continue reading

Showing Change Points in a Trend Chart with R

In this post, I show how to add change points to a trend chart with R. Readers can compare my R and Excel – VBA solutions for the same chart to compare R and Excel VBA charting programming. Continue reading

Boxplots: R Does Them Right

In this post, I define a Tukey boxplot, review the history of boxplots in Excel and walk through an R script for making a proper Tukey boxplot. A link to the source data and R script files is provided. Continue reading

SAS – JMP 8’s Interactive Panel Chart Video

One of my ProcessTrends.Com readers, Andrew, sent me a link to a SAS – JMP 8 video on panel charts. I checked it out and was impressed.

Here’s the link.  The 1 min 41 sec  video gives you a good idea of what JMP can do to interactively make panel charts.  If you are an Excel user, be sure to check it out to see what capabilities you are missing.

What do you think?  Any chance that Microsoft will see the light and make Excel a real analysis tool?



Step Charts: R is Easier Than Excel

In this post, I show how to make a Step Chart with R.  The chart also includes a lowess smoother and annotation.  Readers can visit my site to see how to make a step chart in Excel. Continue reading

Using R to Enhance an Excel Chart

In this post I show how to add a loess fit from R to an Excel chart. Continue reading

Dot Plots versus Stacked Bar Charts – Update 3

This post includes three updates. I have added to the original material to show sequence of my thinking in the chart development based on reader input and charts. Continue reading