5 Replies Latest reply on Mar 10, 2011 1:28 PM by MichaelSpryn

    Chart Y-axis auto-scale problem

    MichaelSpryn

      Summary

      Chart Y-axis auto-scale problem

      Product

      FileMaker Pro

      Version

      11.0v3

      Operating system version

      Mac 10.6.6

      Description of the issue

      Certain combinations of data cause the Y-axis of a chart to no longer auto-scale.  Y = 0 is always shown, which reduces the resolution of the line.

      Steps to reproduce the problem

      Create table with three fields - Sequence, Value1, Value2
      Create three entries in table:
      -  1, 71.4, 67.6
      -  2, 72.6, 84.6
      -  3, 73.3, 72.9
      Create a chart:
      -   Line (Poly-line)
      -   X = Sequence
      -   Y = Value1 and Value2
      -   Use data from current found set

      Expected result

      Y-axis to range from approximately 66 to 86

      Actual result

      Y-axis ranges from 0 to 100

      Configuration information

      In this example, omitting record 1 or 2 will cause the Y-axis to properly auto-scale.  Omitting record 3 has no affect.

      Workaround

      None.  (Can not lock Y range due to changing data values.)

      Chart_bug_20110201.jpg

        • 1. Re: Chart Y-axis auto-scale problem
          MichaelSpryn

          After further research, I think I see a pattern.  It seems that if the maximum Y-value is 125% or more of the minimum Y-value, then the Y scale always starts at 0 instead of being just under the min.  So having a max Y = 124 and a min Y = 100 is OK, but max/min of 125/100 causes the problem.  Similarly the problem occurs with max/min at 13/10, 250/200, 500/400, 1250/1000, etc.  This is especially obvious when working with the higher values because the lines really flatten out and the user can not see any resolution.

          • 2. Re: Chart Y-axis auto-scale problem

            Michael Spryn:

            Thanks for posting!

            This is actually expected behavior. You can get around this by adding minimum and maximum values for the Y-Axis. To get to this option, right click on your chart in layout mode and select Chart Setup and then Format Chart. In there, select Vertical (Y) Axis and enable the check box labeled Set Y-Axis.

            You may also want to submit a feature request to have this function behave differently. This can be done here:

            http://www.filemaker.com/company/contact/feature_request.html

            I would submit it for you but it requests information specific to you.

            TSBear

            FileMaker, Inc.

            • 3. Re: Chart Y-axis auto-scale problem
              MichaelSpryn

              TSBear:

              Thanks for the response!

              I think that this should not be expected behavior.  I am plotting values which randomly (in the eyes of my users) cause their lines to flatten out.  A change of 1 unit makes the plot useless to them.  If their data happens to range from 1000 to 1249, the chart is fine, showing Y from 900 to 1300.  If the 1249 changes to 1250, Y now scales from 0 to 1500 and they lose almost all resolution in the line. Zero through 999 contain no useful visual information.  That empty space represents 80% of the chart.  The chart is useless when that happens.  A coworker is now working on showing the same data by programming in Python with MySQL.  His graphs are much more readable than mine with FileMaker. (They print nicer, too, but that's another post.)  His tools scale the Y axis just bigger than the data being shown.  That just makes sense to me.

              I have already used the Y-axis min/max settings to force some plots to scale correctly, but that is not an acceptable solution.  The user is choosing different types of data from an HVAC system to show in the plot.  Sometimes the data is in the 0-100 range, other times its in 400-600 range (and more).  I can not lock in the min/max because I'll be clipping some data for many plots.  I can not even set the min/max programatically.  Because it's a layout-design only option, I would have to have a layout for each range of data I might need to display.  Even if I could set it programatically, it would slow down the process because I would have to calculate the min and max from the samples chosen by the user.  That would add to the delay it currently takes to produce each chart.   I feel that this is what the FileMaker chart logic should be doing for me.

              Is this really a feature request?

              ...Mike

              • 4. Re: Chart Y-axis auto-scale problem

                Michael Spryn:

                Sorry, I think I chose my words poorly. At this time, the current design of the charting object is to set the Y-axis to begin at 0 when the difference between the min and max Y values exceeds approximately 25%. Therefore, the appropriate course of action to change it would be to submit a feature request.

                TSBear

                FileMaker, Inc.

                • 5. Re: Chart Y-axis auto-scale problem
                  MichaelSpryn

                  Thanks, TSBear.  I will submit a feature request.

                  ...Mike