LSMeans [General Sta­tis­tics]

posted by ElMaestro  – Denmark, 2010-08-20 11:34 (5371 d 20:18 ago) – Posting: # 5815
Views: 9,201

Dear Bharat,

❝ I didn't get you about sneakier way of finding. Because I am a beginner please clarify clearly...


Sorry if I was not expressing myself in a clear fashion.
The normal linear model, written in matrix notation would look like this:

y=Xb+e

y is the vector of abserved values (log Cmax for example).
X is model matrix.
b is the coefficient vector.
e is the vector containg the residuals.

If you have software that fits this model, then it minimses ete (the sum of squares) by playing around with the values in the b vector. By laws of matrix logic, b has as many rows as X has columns, and that is one for each value to be fitted. From this you can extract values (LSMeans) for Test and Reference. Note that when a model with intercept is fitted, there is typically just one column in X that corresponds to an LSMean value; to find the other in such cases you will have to add and subtract a little in order to figger the other LSMean out.

Oh dear, this was not at all clear. Sorry.

Pass or fail!
ElMaestro

Complete thread:

UA Flag
Activity
 Admin contact
23,424 posts in 4,927 threads, 1,669 registered users;
51 visitors (0 registered, 51 guests [including 6 identified bots]).
Forum time: 07:52 CEST (Europe/Vienna)

My doctor gave me six months to live,
but when I couldn’t pay the bill
he gave me six months more.    Walter Matthau

The Bioequivalence and Bioavailability Forum is hosted by
BEBAC Ing. Helmut Schütz
HTML5