Author Topic: UPDATED: Forcing the same range on all axes  (Read 3021 times)

Ron D.

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UPDATED: Forcing the same range on all axes
« on: January 01, 2015, 02:58:36 AM »
UPDATED: Sliver v1.4 includes a feature to manually enter a range for one or more axes.

Sometimes data is understood better when the PC plot has consistent ranges on all axes regardless of whether a particular axes has values that extend to the ends. For example, the attached PDF export shows running speeds (inverse speeds, really, of seconds per kilometer) at each split for the top 2000 runners of the 2014 Berlin Marathon (it looks much better downloaded and opened in Acrobat than just rendered in your browser). If each axis were plotted in its own range, it would be visually difficult to tell if the runners sped up or slowed down between splits. So here each axis was forced to have the same range that spans the ranges of all the variables, except the last axis which just mapped the runner's lines to the final place overall.

To do this, you need to set the same the maximum and minimum values across all variables being plotted. One way to do this automatically is to use the DataTools-->Add Rows of Min/Max Values option. This adds a row to your data file in which all chosen variables have the same overall minimum value, and another row in which they have the same overall maximum value. For any variable you do not choose, the new rows will simply contain the minimum and maximum values of that variable, so this function will have no effect on its range.

If you prefer to set the ranges manually, or if not all variables in the data file are being plotted, you can use the DataTools-->View Column Min/Max Values option to show the maximum and minimum values for each variable. Then you can manually add a row of minimum values and a row of maximum values to the data file.

In either of the two options above, the axes of the PC plot will all have this same range when the data is plotted. There will be horizontal polylines across the tops and bottoms of the axes from the two added lines. Swipe these to select them, assign them to a color brush, and then hide that brush, leaving the original data plotted on axes with identical ranges.

An alternative available in Sliver v1.2 is to save your existing session to a file using the File-->Save Session menu option, then use a text editor to change the last n lines of the file to have the same min,max values, where n is the number of axes, and then restore the session. More information about the format of the session files can be found in Appendix C of the User's Manual. This does not require any extra lines to be swiped and hidden when the data is plotted.

« Last Edit: January 17, 2017, 01:34:42 AM by Ron D. »


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Re: Forcing the same range on all axes
« Reply #1 on: January 01, 2015, 09:36:48 AM »
Thanks Ron,

I was going to ask about how to do this.