WEIGHTING AND OBSERVATION FORMS

Uniform weighting (known as simple least squares) is appropriate wJien the expected variances of the observations are equal and is commonly used when these values are unknown. GREGPLUS uses this w eighting when called with JWT = 0 the values MwijJ = 1 are then provided automatically. 

Observations done with uniform relative precision are fairly common. For example, reported catalytic rate data often include adjustments of reaction temperature, catalyst activity, and other variables to standard values. These combined adjustments amount to a correction factor for the catalyst mass in each event u = I. n. Then the total rate of production of any product P in a reactor experiment can be expressed as 

Here F is the total molar feed rate to the reactor. Ax is the production of the product P in moles per mole of feed, and W is the catalyst mass. 

The function = In Rp has the following variance according to Eq. (4.D-4), with the errors in InF, InAxu, InC, and lnMK regarded as random independent variables  

The remaining sections of this chapter are implemented in the package GREGPLUS, described and demonstrated in Appendix C. 

---