Usage: |
{xr,yr,wxr,offr,ctrl} = glminit(code,x,y{,opt})
|
Input: |
| code | text string, the short code for the model (e.g.
"bilo" for logit or "noid" for ordinary PLM).
|
| x | n x p matrix, the predictor variables.
|
| y | n x 1 vector, the response variables. Binomial
y[i] may have (integer) values between 0
and opt.wx[i] or opt.wx (if opt.wx is scalar).
|
| opt | optional, a list with optional input.
"glmopt" can be used to set up this parameter.
The order of the list elements is not important.
|
| opt.weights | string, type of weights. Can be "frequency"
for replication counts, or "prior" (default)
for prior weights in weighted regression.
|
| opt.wx | scalar or n x 1 vector, frequency or prior
weights. If not given, set to 1.
|
| opt.off | scalar or n x 1 vector, offset. Can be used for
constrained estimation. If not given, set to 0.
|
| opt.shf | integer, if exists and =1, some output is produced
which indicates how the iteration is going on.
|
| opt.miter | integer, maximal number of iterations. The default
is 10.
|
| opt.cnv | integer, convergence criterion. The default is 0.0001.
|
| opt.fscor | integer, if exists and =1, a Fisher scoring is
performed (instead of the default Newton-Raphson
procedure). This parameter is ignored for
canonical links.
|
| opt.pow | optional, power for power link.
|
| opt.nbk | scalar, extra parameter k for negative binomial
distribution. If not given, set to 1 (geometric
distribution).
|
Output: |
| xr | nr x p matrix, the predictor variables,
eventually reduced up to replications. |
| yr | nr x 1 or nr x 2 or nr x 3 matrix,
either the response values, or sums of response
values in 1st column and sums of a function
of response values in the 2nd and 3rd column (e.g.
sums of y^2 or log(y), see glmll).
(In the case of replicated data, the number of
replications should be given in wx, yr[,1] contains
the sums of all responses for a replication,
yr[,2:3] contains sums of e.g. y^2 or log(y) for a
replication.) |
| wxr | nr x 1 vector or scalar, weights. |
| offr | nr x 1 vector or scalar, offset. |
| ctrl | 6 x 1 integer vector or scalar, contains control
parameters shf, miter, cnv, fscor, pow, nbk
or shf alone.
Defaults for miter, cnv, fscor, pow, nbk are
10, 0.0001, 0, 0 (logarithm link) and 1. |