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The LIFEREG Procedure |
lower | upper | Comparison | Interpretation | |||
not missing | not missing | equal | no censoring | |||
not missing | not missing | lower < upper | censoring interval- | |||
missing | not missing | upper used as left- | ||||
censoring value | ||||||
not missing | missing | lower used as right- | ||||
censoring value | ||||||
not missing | not missing | lower > upper | observation not used | |||
missing | missing | observation not used |
a: model time*flag(1,3)=temp; b: model (start, finish)=; c: model r/n=dose;
Task | Option | ||
Model specification | |||
specify distribution type for failure time | DISTRIBUTION= | ||
request no log transformation of response | NOLOG | ||
initial estimate for intercept term | INTERCEPT= | ||
hold intercept term fixed | NOINT | ||
initial estimates for regression parameters | INITIAL= | ||
initialize scale parameter | SCALE= | ||
hold scale parameter fixed | NOSCALE | ||
initialize first shape parameter | SHAPE1= | ||
hold first shape parameter fixed | NOSHAPE1 | ||
Model fitting | |||
set convergence criterion | CONVERGE= | ||
set maximum iterations | MAXITER= | ||
set tolerance for testing singularity | SINGULAR= | ||
Output | |||
display estimated correlation matrix | CORRB | ||
display estimated covariance matrix | COVB | ||
display iteration history, final gradient, | ITPRINT | ||
and second derivative matrix |
DISTRIBUTION= | NOLOG specified? | Resulting distribution |
EXPONENTIAL | No | Exponential |
EXPONENTIAL | Yes | One parameter extreme value |
GAMMA | No | Generalized gamma |
GAMMA | Yes | Generalized gamma with untransformed responses |
LOGISTIC | No | Logistic |
LOGISTIC | Yes | Logistic (NOLOG has no effect) |
LLOGISTIC | No | Log-logistic |
LLOGISTIC | Yes | Logistic |
LNORMAL | No | Lognormal |
LNORMAL | Yes | Normal |
NORMAL | No | Normal |
NORMAL | Yes | Normal (NOLOG has no effect) |
WEIBULL | No | Weibull |
WEIBULL | Yes | Extreme value |
Type of List | Specification | |
list separated by blanks | initial=3 4 5 | |
list separated by commas | initial=3,4,5 | |
x to y | initial=3 to 5 | |
x to y by z | initial=3 to 5 by 1 | |
combination of methods | initial=1,3 to 5,9 |
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