Table 4. glmnet timings for fitting a lasso problem in various settings†.
| Setting | Correlation | Time (s) without strong rule | Time (s) with strong rule |
|---|---|---|---|
| Gaussian | 0 | 0.99 (0.02) | 1.04 (0.02) |
| 0.4 | 2.87 (0.08) | 1.29 (0.01) | |
| Binomial | 0 | 3.04 (0.11) | 1.24 (0.01) |
| 0.4 | 3.25 (0.12) | 1.23 (0.02) | |
| Cox | 0 | 178.74 (5.97) | 7.90 (0.13) |
| 0.4 | 120.32 (3.61) | 8.09 (0.19) | |
| Poisson | 0 | 142.10 (6.67) | 4.19 (0.17) |
| 0.4 | 74.20 (3.10) | 1.74 (0.07) |
There are p=20000 predictors and N =200 observations. Values shown are the mean and standard error of the mean over 20 simulations. For the Gaussian model the data were generated as standard Gaussian with pairwise correlation 0 or 0.4, and the first 20 regression coefficients equalled to 20, 19,…,1 (the rest being 0). Gaussian noise was added to the linear predictor so that the signal-to-noise ratio was about 3.0. For the logistic model, the outcome variable y was generated as above, and then transformed to {sgn(y) + 1}/2. For the survival model, the survival time was taken to be the outcome y from the Gaussian model above and all observations were considered to be uncensored.