Go Back   TechArena Community > Software > Windows Software
Become a Member!
Forgot your username/password?
Register Tags Active Topics RSS Search Mark Forums Read

Sponsored Links



What are an improvements of LINEST function in Excel 2003?

Windows Software


Reply
 
Thread Tools Search this Thread
  #1  
Old 13-03-2010
Member
 
Join Date: Jul 2006
Posts: 182
What are an improvements of LINEST function in Excel 2003?
  

Hi friends,
I have done some basic things of the statistical functions. I have been told to write about an improvements of the Linest function. I have an idea about the Linest function but I don't know the improvements of it. So thought to ask you guys about it. Please tell me what are an improvements of LINEST function in Excel 2003? Hope that you all understood what I want to say.?!? Please reply me soon.!!

__________________
"Yea though I walk through the valley of the shadow of death... I will fear no evil." -Psalms 23

K8N Diamond Plus (BIOS v1.2)
AMD Athlon 64 X2 4400+
Antec TruControl 550W
NVidia GeForce 7900GT (NGO v1.8466 BETA)
OCZ Platinum 2x1GB (2-3-2-5)
SATA: WD740
PATA: 2xWD2500, WD1200, NEC DVD/RW
Reply With Quote
  #2  
Old 13-03-2010
Member
 
Join Date: Apr 2008
Posts: 4,641
Re: What are an improvements of LINEST function in Excel 2003?

The following improvements have been made: the correction formula for the sum of squares when the third argument LINEST set to FALSE and transition to the QR decomposition method to determine the regression coefficients. The QR decomposition has two advantages :
  1. better numerical stability (rounding errors usually smaller);
  2. analysis problems of collinearity.
Collinearity remains a major challenge, especially after having performed the tests on data-sets from NIST.
Reply With Quote
  #3  
Old 13-03-2010
Member
 
Join Date: May 2008
Posts: 4,338
Re: What are an improvements of LINEST function in Excel 2003?

Regardless of the value of the third argument, LINEST was calculated using a method that ignores the problems of collinearity. The presence of collinearity caused rounding errors, and standard errors of regression coefficients and degrees of freedom inadequate. The rounding issues were sometimes so large that LINEST filled its output table with # NUM!. Generally, LINEST gives satisfactory results when the following conditions are met :
  • No column of the explanatory variables are collinear (or nearly collinear).
  • The third argument LINEST is TRUE or omitted.
The resolution of regression coefficients using the "normal equations" However, more likely to cause rounding errors than using the method of QR decomposition used in Excel 2003 and in later versions of Excel. Even if these factors cause more rounding errors, they do not pose a risk in most practical cases.
Reply With Quote
  #4  
Old 13-03-2010
Member
 
Join Date: Apr 2008
Posts: 4,086
Re: What are an improvements of LINEST function in Excel 2003?

LINEST has been greatly improved in Excel 2003 and in later versions of Excel. If you are using an earlier version of Excel, make sure the columns of explanatory variables are not collinear before using LINEST. It is recommended to use the workaround suggested in this article when the third argument LINEST set to FALSE. Note that collinearity does not pose a problem in a small percentage of cases and appeals to LINEST when the third argument set to FALSE are also relatively rare in practice.
__________________
Ram requirement for various OS
Reply With Quote
  #5  
Old 13-03-2010
Member
 
Join Date: May 2008
Posts: 353
Re: What are an improvements of LINEST function in Excel 2003?

Earlier versions of Excel gives satisfactory results with LINEST in the absence of collinearity or when the third argument LINEST is TRUE or omitted. Improvements in LINEST concern the linear regression tool of Analysis ToolPak calling LINEST and related functions include :
  • TREND
  • LOGEST
  • GROWTH
Reply With Quote
  #6  
Old 13-03-2010
Member
 
Join Date: Aug 2006
Posts: 287
Re: What are an improvements of LINEST function in Excel 2003?

LINEST used an incorrect formula to find the total sum of squares when the third argument LINEST was set to FALSE. This formula gave erroneous results in the sum of squares regression, and for outputs that depend on R squared and F statistic. The columns of variables form a matrix. If the intersection is adjusted, there is actually an additional column 1 that is not on your worksheet. The QR decomposition determines the order of this matrix. The preceding formulas for the DF regression must be replaced by the following formulas :
  1. If "adjustment" Regression DF equals the order of the columns of the matrix of explanatory variables minus one'
  2. In case of "non-adjustment" Regression DF equals the order of the columns of the matrix of explanatory variables.
__________________
Dimension 1100 (FMY032J) mini-tower
2.53ghz Intel Pentium 4
80 gig nfts HDD
512 RAM
Main circuit board: Dell 0CF458
BIOS: Dell A00
Display: Intel(R) 82865G Graphics Controller [Display adaptor]
Multimedia: Sound MAX Integrated Digital Audio
Windows XP Home SP2
Reply With Quote
Reply

  TechArena Community > Software > Windows Software
Tags: , , , , ,



Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads for: "What are an improvements of LINEST function in Excel 2003?"
Thread Thread Starter Forum Replies Last Post
Queries regarding improvements made in Sound Finder and Silence Finder function in Audacity Elias Blackman Windows Software 6 11-03-2012 02:33 PM
Description of the LINEST function in Excel 2003 PsYcHo 1 Windows Software 5 13-03-2010 04:47 AM
How LOGEST interacts with LINEST in Excel? MarceloQuad Windows Software 5 13-03-2010 04:22 AM
How TREND interacts with LINEST in Excel? Vandam Windows Software 5 13-03-2010 03:31 AM
What is VAR and VARP improvements and Data Consolidation in Excel? Flaco Windows Software 5 11-03-2010 05:09 AM


All times are GMT +5.5. The time now is 06:40 PM.