STDEV returns the standard deviation of a set of values

Syntax

  1. STDEV(Pno%, Ndim%, "ColLab$_1",.., "ColLab$_Ndim%")
  2. STDEV(0, Npoints%, x_1, y_1, x_2, y_2,...)
  3. STDEV(@ObjFn(..), Ndim%, @ObjColPar_1,.., @ObjColPar_Ndim%)
  4. STDEV(Telitab$, Ndim%, "ColLab$_1",.., "ColLab$_Ndim%")

Arguments

  • Pno% is the number that refers to the TeLiTab sets in the Data slot. Pno% should be an integer value or a parameter which is assigned an integer value and is the number of theTeLiTab set in the expressions' data slot.
  • Npoints% is the number of points (x,y) that are given in direct definition.
  • @ObjFn() refers to the Object from which data will be used.
  • TeLiTab$ refers to the string parameter that contains the TeLiTab.
  • Ndim% is the number of dimensions (or columns in the table...).
  • "ColLab$_1" and @ObjColPar_1 etc refer to the columns that will be used;

Remarks

  1. See also Telitab access for a generic description on the use of TeLiTab data
  2. Similar to other Data analysis functions, the STDEV is a convenient way to evaluate data. Please also look at these functions for syntax examples
  3. For a multi-dimensional dataset the STDEV will be determined over all columns.
  4. The standard deviation is calculated using the "nonbiased" or "n-1" method.
  5. STDEV uses the following formula:

    SQRT(n*Sigma_X^2 - (Sigma_X)^2/(n*(n-1)))

Examples

Suppose 10 engine parts made by the same machine during a production run are collected as a random sample and measured for breaking strength. STDEV estimates the standard deviation of breaking strengths for all the parts. The sample values are provided in the STDEV function as follows:

SET$= 
0 
1 "Strength" 
"1"  1465 
"2"  1421 
"3"  1457 
"4"  1428 
"5"  1416 
"6"  1477 
"7"  1422 
"8"  1452 
"9"  1412 
"10" 1409

STDEV(SET$, 1, "Strength") returns 24.52

 

Quick links: Functions overview | Attribute overview | Constants overview | Dimensions overview


  • No labels