Boxplot outliers

Lars Iversen · Post by **Lars Iversen** » Fri Jul 04, 2008 9:33 am

Hi

I have a question about outliers in boxplots. I haven't been able to find an answer in any documentation.

What is the precise condition for distinguishing between mild and extreme outliers in a box plot?
What condition is required for a point to be an outlier and what condition is required for a point to be an extreme outlier?

Thanks in advance
Lars Iversen

Narcís · Post by **Narcís** » Wed Jul 16, 2008 9:08 am

Hi Lars,

Mild outliers are defined in TeeChart like this:

Code: Select all

if (((tmpVal >= innerFence3) && (tmpVal <= outerFence3)) || ((tmpVal <= innerFence1) && (tmpVal >= outerFence1)))

This can also be done manually as in the example at All Features\Welcome!\Chart Styles\Statistical\Box-Plot\Custom values in the new features demo, available at TeeChart's program group.

Basically, you can do anything with box plot, as long as you have meaningful values.

Lars Iversen · Post by **Lars Iversen** » Tue Jul 29, 2008 1:14 pm

Hi

Thanks for the reply.

What exactly is the innerfence and outerfence?
if I do not set the values of inner and outer fence myself what formulars does teechart then use to calculate them?

Thanks in advance

Narcís · Post by **Narcís** » Tue Jul 29, 2008 1:27 pm

Hi Lars,

On my 16th March 2007 post on this thread I described what inner-fence and outer-fence are and how they are calculated.

Hope this helps!