6 Replies Latest reply on May 28, 2013 11:42 AM by Larry G. Schneider

    Is there a way to improve the accuracy of charts in Illustrator CS3?

    Chart Daddy

      I've recently come up againast a wall in Illustrator. I'm producing a large, detailed pie chart, and the fine slices aren't being shown accurately.

       

      For example, if you prodoce a simple 3-slice pie chart using: 99.5, 0.1, 0.4 .... the smallest slice will be lost. It looks as though Illustrator will not show anything under a quarter of a per cent.

       

      I'd appreciate any help you can offer.

       

      Thx.

        • 1. Re: Is there a way to improve the accuracy of charts in Illustrator CS3?
          Mylenium Most Valuable Participant

          And why would you even want to produce such a graphic? Small values  such as you describe them fall below what is statistically significant, making any data graphic based thereon a direct candidate for Junk Charts. It's simply bad data graphic design and I'm sure Mr. Tufte would agree on this. If you still want to go through with this, I don't really see the problem - 0.1% is 0.36 degrees, which will look only like a tapered stroke on even the biggest poster. Therefore rounding values up or down is really the only feasible option, especialyl since trying to actually print such a graphic would require minimum separations and area sizes to cater for dot gain/ ink bleed. One way or the other, your representation will be biased. That would also be true, if you only showed a section of the whole chart. No matter how you twist and turn it, your graphic would only contain misinformation, so how you draw it matters very little and AI's deficiencies in precision handling are the least of your worries.

           

          Mylenium

          • 2. Re: Is there a way to improve the accuracy of charts in Illustrator CS3?
            Chart Daddy Level 1

            Thanks for that, are you feeling better now?

             

            The chart's currently sitting on a 40cm square document and the 0.2% slithers are both visually significant and relevant to the data set. By rounding the slices to the nearest .25 the application is distorting the data (to a degree which even Mr Tufte would couldiser significant, I'm sure).

             

            ps: If you're still feeling angry perhaps you should go for a quick run around the block.

            • 3. Re: Is there a way to improve the accuracy of charts in Illustrator CS3?
              Scott Falkner Level 5

              My my, people are sensitive this week.

              • 4. Re: Is there a way to improve the accuracy of charts in Illustrator CS3?
                Mylenium Most Valuable Participant

                Even Mr. Tufte would accept a "lie factor" within reason as long as the overall graphic retains the core of its meaning. And I don't see any problem with that here - your 0.1% deviation is just a blip and would in most scientific analyses probably be eliminated as random noise, so ramp it up. And statistically, it is irrelevant, no matter whether you employ a simple logarithmic filter or more complex methods. All that aside, by choosing a pie chart (!) that is only 40cm small (!) you are simply choosing the wrong means of visualizing your data. A simple scatter plot would probably be more informative. You can hate me for that and question my credibility in the matter, but that's just how I see it and Tufte would, too. You really should read those books of his. Well, what do I care. The world is full of bad data graphics, what's one more? I'm out of this discussion.

                 

                Mylenium

                • 5. Re: Is there a way to improve the accuracy of charts in Illustrator CS3?
                  blatherpig

                  Have to say - Illustrator still shows this problem in CS6 - you can only fudge it!

                   

                  I have segments ranging from 24% to 0.9%  and yet Illustrator is was showing a 0.9% slice larger than a 0.97%

                   

                  I find it really frustrating reading answers as above that basically say - its you, not the program. The long winded answers above are not in the slightest bit helpfull. Saying that a small percentage is insignificant is NOT an answer to the questioners issue!

                   

                  I do know the question was three years ago by the way!

                  • 6. Re: Is there a way to improve the accuracy of charts in Illustrator CS3?
                    Larry G. Schneider Adobe Community Professional & MVP

                    Your best bet is to do it in a program which doesn't have the limitations of AI when it comes to graphs.