Tips and Tricks: Managing long category values

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Long category values occur frequently in real world use cases.  This can happen with graphs for analysis of clinical research data, and also for graphs showing survey data where the question asked may be long (even a paragraph).  Managing such long categories on the x or y axis is always a challenge.

With the SAS 9.4 release, SGPLOT and GTL support many features to help manage long category values by splitting and wrapping the value to fit in the space for each category.  On the x-axis, the space for each category is limited by the number of categories.  By default, the SGPLOT procedure will split the categories on a "white space".  An option is also available to set the split character(s) which may be necessary in some cases for international use cases, or for categories without white space (such as URLs).

Often, it is helpful to position the categories on the y-axis.  This provides a more efficient layout for long categories.  In a recent article, I showed some features useful for graphs with long category values.  Many of you commented on the need for finer control of  splitting and wrapping.  I will address some available features here.

The graph below shows the default behavior of splitting of the y-axis values when using FITPOLICY=Split.  Using this feature, the tick values are split at a "white space" to provide the best fit for the value, utilizing about 25% of the width of the graph for splitting.  If Y and Y2 axis are in use, both will use up to about 25% each .  Note, I have reduced the size of the y-axis values font a bit.  The footnote provides information on options used.  See link at the bottom for the full code.

Now, you may want better control over the split point in the values.  This can be done by inserting a custom split character in the value, and instructing the software to split on the presence of this character.   For the graph below, I have added a ":" after the SAS product name, and used SPLITCHAR=":"  Note, now the values are all split only after the ":".  Also, the split character is dropped from the display when split occurs.  You can provide multiple characters in the string.  Split will occur at each character.

In the case above, since I provided only 1 ":" character in each category value, only one split will occur.  If the tick value is still too long it will take space away from the bar chart.

Another useful option is the SPLITCHARNODROP.  This option instructs to RETAIN the split character in the display.  In the graph below, I have used this option.  Note, the ":" after the product name are now retained.

This option can be very useful when the y-axis category values are URL links.  Providing SplitChar="." allows these long strings to be split and wrapped at the appropriate "." while still retaining the "." in the URL string.

SGPLOT Code: Split  

 

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About Author

Sanjay Matange

Director, R&D

Sanjay Matange is R&D Director in the Data Visualization Division responsible for the development and support of the ODS Graphics system, including the Graph Template Language (GTL), Statistical Graphics (SG) procedures, ODS Graphics Designer and related software. Sanjay has co-authored a book on SG Procedures with SAS/PRESS.

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2 Comments

  1. Michelle Homes

    Reminds me of the PROC PRINT SPLIT='split-character' option... is that where SPLITCHAR option stemmed from? I also like the SPLITCHARNODROP - handy to have the option so the split character can be retained. Useful and flexible options!

    • Sanjay Matange
      Sanjay Matange on

      Yes, we try to keep some consistency within and across procedures. I am sure this was influenced by some previous usage. Glad to know you could find these useful.

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