**Table of Contents**

This page reports the performance of different algorithms for training classifiers. This is the list of implementations used for the experiments.

The experiments use the training (and test) sets of rcv1.binary (binary). All of the experiments were run on Debian GNU/Linux 4.0 over Intel Xeon 5140 CPU (2.33GHz) with 4GB main memory.

Table 1 reports the training speed and accuracy. Classias, LIBLINEAR, and LIBSVM are roughly comparable in terms of the accuracy. However, LIBLINEAR trains classification models much faster than Classias. We are planning to investigate whether the speed difference can be reduced by tuning the parameters (initial learning rate, convergence criterion) of the training algorithms in Classias.

**Table 1. Performance of training**

Software | Algorithm | Obj | Acc | # Iters | Time | Speed | L2norm | Active | C |
---|---|---|---|---|---|---|---|---|---|

[s] | [s/iter] | ||||||||

Classias | L1-reg LR (OW-LQN) | 1035.8 | 0.9664 | 233.8 | 8.91 | 0.038 | 299.5 | 1562 | 0.10 |

Classias | L2-reg LR (L-BFGS) | 567.9 | 0.9705 | 116.2 | 4.35 | 0.037 | 179.9 | 0.01 | |

Classias | Averaged Perceptron | 28.8 | 0.9584 | 100.0 | 1.73 | 0.014 | 95.8 | 1.00 | |

Classias | L2-reg LR (Pegasos) | 573.6 | 0.9703 | 359.6 | 12.58 | 0.032 | 176.7 | 0.01 | |

Classias | L2-reg L1-SVM (Pegasos) | 1305.7 | 0.9707 | 203.6 | 6.55 | 0.029 | 48.3 | 0.40 | |

Classias | L1-reg LR (TG) | 437.0 | 0.9703 | 998.8 | 46.15 | 0.043 | 52743.1 | 14427 | 0.02 |

Classias | L1-reg L1-SVM (TG) | 1389.7 | 0.9687 | 452.6 | 19.50 | 0.040 | 4761.9 | 9665 | 0.40 |

LIBLINEAR | L2-reg LR | 13470.0 | 0.9700 | 1.30 | 10.00 | ||||

LIBLINEAR | L2-reg L2-SVM (dual) | 1163.8 | 0.9712 | 0.38 | 1.00 | ||||

LIBLINEAR | L2-reg L2-SVM (primal) | 1183.4 | 0.9713 | 0.92 | 1.00 | ||||

LIBLINEAR | L2-reg L1-SVM (dual) | 1853.1 | 0.9703 | 0.49 | 2.00 | ||||

LIBLINEAR | Multi (Crammer & Singer) | 680.7 | 0.9705 | 0.48 | 0.40 | ||||

LIBLINEAR | L1-reg L2-SVM | 0.0 | 0.9677 | 1.45 | 1330 | 1.00 | |||

LIBLINEAR | L1-reg LR | 0.0 | 0.9661 | 9.20 | 1141 | 4.00 | |||

LIBSVM | linear kernel | 1483.8 | 0.9707 | 167.4 | 1.00 |

- Algorithm
- The description of the algorithm used for training. Several abbreviations are used:
*L1-regularized (L1-reg), L2-regularized (L2-reg), Logistic Regression (LR), L1-loss SVM (L1-SVM), L2-loss SVM (L2-SVM), Truncated Gradient (TG)*. - Obj
- The final value of the objective function. For averaged perceptron, this value presents the number of violations.
- Acc
- The average accuracy of 5-fold cross validation.
- # Iters
- The number of iterations.
- Time [s]
- The average time, in seconds, elapsed for one run of 5-fold cross validation.
- Speed [s/iter]
- The averaged elapsed time, in seconds, for an iteration.
- L2norm
- The L2-norm of feature weights.
- Active
- The number of active (non-zero) features.
- C
- The coefficient for the regularization. For Classias and LIBLINEAR, we tried 0.01, 0.02, 0.04, 0.1, 0.2, 0.4, 1.0, 2.0, 4.0, 10.0, and chose the coefficient that yielded the best accuracy. We set C = 1.0 for LIBSVM.