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Stats Extension Limits

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I have a histogram chart on which I would like to display the spac limits.

The data I am using for development ranges from 30 to 66. The spec limits

are 32 - 36.

I tried this:

stats.Gallery.Histogram.LimitLeft = lowerSpec;

stats.Gallery.Histogram.LimitRight = upperSpec;

However that set the left limit line to just inside the right edge of the

chart (about where 65 would be) and put the right limit line completely off

the chart. So i figured that the value should be the number of intervals

from the chart minimum, so I tried this:

double chartMin = stats.Calculators[0].Get(Analysis.Min);

stats.Gallery.Histogram.LimitLeft = Convert.ToInt32(lowerSpec - chartMin);

stats.Gallery.Histogram.LimitRight = Convert.ToInt32(upperSpec - chartMin);

This moved the lines closer to what they should be, but they were still

wrong (the left line was just left of 34 and the right line was just left of

41). So I figured that I had to take into account the size of the interval

(which in this case was about 1.8), so I tried this:

double chartMin = stats.Calculators[0].Get(Analysis.Min);

double chartMax = stats.Calculators[0].Get(Analysis.Max);

double intervalValue = (chartMax -


stats.Gallery.Histogram.LimitLeft = Convert.ToInt32((lowerSpec -


stats.Gallery.Histogram.LimitRight = Convert.ToInt32((upperSpec -


This moved them even closer to being correct. The left line was just to the

left of 32 and the right line was just inside the bar labeled 36). However

there are tick marks & labels for 32 & 36 on the chart and the lines are not

lined up with either of them. My boss asked me why, if those are the specs,

the lines aren't on the tick marks and I could not give him an answer.

From reading your documentation it sounds like you just set the LimitLeft

and LimitRight values to the value you would like it to be, in this case it

would be 32 & 36, but it does not work that way. Did I read it wrong or am

I missing something here?

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Your documentation says that the limits are "used to get or set a value for

the limit" not a number of intervals. But anyway, is there any way to find

the interval size without calculating it yourself like I had to do? I don't

see any properties or methods to get this value.

"SoftwareFX Support" <noreply@softwarefx.com> wrote in message


> LimitLeft and LimitRight refer to a NUMBER of intervals.


> If your interval size is say 10 and you want to set the Left Limit to 30


> the Data Min is Zero, you will set:


> LimitLeft = 3


> --

> FP

> Software FX



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Yes. If you are assigning DataMin and DataMax:

intervalSize = ((statistics1.Gallery.Histogram.DataMax -



intervalSize = ((statistics1.Calculators[0].Get(Analysis.Max) -




Software FX

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I was looking into this in a little more detail and I realized something 

that I didn't think of in my previous post:

The percentage displayed DOES NOT correspond to the actual data but to the

z-scores of the Normal distribution, this is by design. You are not seeing

the percentage of your "sample", you are seeing the percentage of the


So we are actually not counting how many points went outside/inside the


As for the formatting (number of decimals displayed) that is something that

you should be able to control. We will add a property if necessary or

associate it with another property (if it makes sense).



Software FX

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