Re: [EnergyPlus_Support] Performance curve for the chiller

["Michael J. Witte" <mjwitte@xxxxxxxx>]

On 22 Feb 2005, at 9:10, wing sun lee wrote:

> 
> I have already checked the microsoft office excel, but it can only solve the
> curve fit for linear and quadratic equation by the Linest() function.
> 

There is a trick that was taught to me that allows "Linest" to be used to fit 
higher power equations.  You must first create additional columns which compute 
the higher powers or other forms of the independent variables.  For example, to 
solve a bi-quadratic in Excel:
Col A= X
Col B= X^2
Col C= Y
Col D= Y^2
Col E= X*Y
Col F= Dependent variable

Then tell Linest that columns A:E are the independent variables and col F is 
the dependent variable.  I will try to prepare a sample spreadsheet to post in 
the files area.

Mike

========================================================
Michael J. Witte, GARD Analytics, Inc.
EnergyPlus Testing and Support      
EnergyPlus-Support@xxxxxxxx




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