Every time I think I know what's going on, suddenly there's another layer of complications.
2018年12月14日星期五
2018年10月11日星期四
steps for simulation sample size
- Write the statistical model mathematically.
- Generate the sample according to the model with sample size N.
- Fit the model, perform the test, and record the rejection or acceptance of hull hypothesis.
- Repeat step 2 and 3 n (generally I used 5000) times.
- Calculate the power by (# of rejections)/n.
6 If power is too higher, decrease sample size N, repeat 2 - 5. If power is too lower, increase sample size N, repeat 2 - 5.
2018年9月25日星期二
number of basis fuction for spline regression
The number of basis function is n+d+1, where n is the number of (internal) knots, where d is the degree of the basis function.
2018年6月13日星期三
2018年6月4日星期一
2018年5月21日星期一
Producing graphs of the survival and baseline hazard function after Cox regression
- When only
plots=survival
is specified on the proc phreg
statement, SAS will produce one graph, a “reference curve” of the survival function at the reference level of all categorical predictors and at the mean of all continuous predictors.
https://stats.idre.ucla.edu/sas/seminars/sas-survival/
plots=survival
is specified on the proc phreg
statement, SAS will produce one graph, a “reference curve” of the survival function at the reference level of all categorical predictors and at the mean of all continuous predictors.2018年4月18日星期三
Heine–Borel theorem
https://ipfs.io/ipfs/QmXoypizjW3WknFiJnKLwHCnL72vedxjQkDDP1mXWo6uco/wiki/Heine%E2%80%93Borel_theorem.html
订阅:
博文 (Atom)