Keithley 4200A-SCS - EXPFITB Formulator Function

Mo
del 4200A-SCS Parameter Analyzer Reference Manual Section 6:
Clarius
4200A-901-01 Rev. C / February 2017 6-249
EXPFITB Formulator function
Performs an exponential fit. Fits the following exponential relationship to a specified range of values in two
columns (vectors): one column, VX, containing X values and the other column, VY, containing Y values:
Y = EXPFITA * e
(EXPFITB * X)
Where EXPFITA and EXPFITB are fit constants.
Returns the value of the constant EXPFITB in the relationship above.
Usage
EXPFIT(VX, VY, STARTPOS, ENDPOS)
VX
The name of any column (vector) listed under Columns
VY
The name of any column (vector) listed under Columns
STARTPOS
For the range of X and Y values to be exponentially fitted, the row number (index) of
the starting values
ENDPOS
For the range of X and Y values to be exponentially fitted, the row number (index) of
the ending values
Details
If a VX or VY value at either STARTPOS or ENDPOS is an invalid number (that is, the value is #REF),
the function will not return a valid result.
Example
DIODEIDEALITY = 1/(EXPFITB(ANODEV, ANODEI, 2, LASTPOS(ANODEV))*0.0257)
Also see
EXPFITA (on page 6-248)
EXPFITB (on page 6-249)