17: Standard Deviation - Unipulse M525B Operation Manual

4 FOR GREATER USE OF THE PRINTER

17: Standard Deviation

Select a standard deviation calculating expressions.
There are two types of calculating expression.
Name of settings
Selection
Details of settings
Chapter
4
Caution in selection
32
32
17: Standard Deviation
0. σ
n
1. σ
n-1
When all data in a group is used, and the standard deviation of the group is obtained.
σ
n
n
(
∑
i = 1
σ n
=
- - - - - - - - - - - - - - - - - - - - - - - -
σ Several pieces of sample data in a group are used, and the standard deviation of the
n-1
group is estimated from the sample data.
n
∑
σ n 1 i =
=
–
- - - - - - - - - - - - - - - - - - - - - - - -
σ calculates the standard deviation only with the sample data extracted from all print data.
n-1
Therefore, if it is used when the quantity of data is small, the reliability of the value becomes
low.
* This setting item is necessary
when the GT/ST Print Format setting is 2 - 4.
(initial value)
σ
○
2
○
χ i χ )
–
n
All data in the group is used, and the
standard deviation is obtained.
σ
○
2
( χ i χ )
–
○
1
n 1 –
Only several points of sample data are used, and
the overall standard deviation is estimated.
n
Group
○
○
○ ○
○
○
○
n-1
Group
○
○
○ ○
○
○
○