svmocas(1) train a binary linear SVM classifier


svmocas [options] example_file model_file


svmocas is a program that trains a binary linear SVM classifier using the Optimized Cutting Plane Algorithm for Support Vector Machines (OCAS) and produces a model file.

example_file is a file with training examples in SVM^light format, and model_file is the file in which to store the learned linear rule f(x)=w'*x+w0. model_file contains d lines, where d is the number of data dimensions. The first n lines are coordinates of w and the last line is w0.


A summary of options is included below.

General options:

Show summary of options.
-v (0|1)
Set the verbosity level (default: 1)

Learning options:

-c float
Regularization constant C. (default: 1)
-C constants_file
If specified, each example has a different regularization constant, taken from the text file constants_file. Each line of the text file must contain a single constant (positive double) for the corresponding example. If -C is used, then the -c option is ignored.
-b (0|1)
Value of the L2-bias feature. A value of 0 implies not having bias. (default: 0)
-n integer
Use only the first integer examples for training. By default, integer equals the number of examples in example_file.

Optimization options:

-m (0|1)
Solver to be used:

0 ... standard cutting plane (equivalent to BMRM, SVM^perf)

1 ... OCAS (default)
-s integer
Cache size for cutting planes. (default: 2000)
-p integer
Number of threads. (default: 1)

Stopping conditions:

-a float
Absolute tolerance TolAbs: halt if QP-QD <= TolAbs. (default: 0)
-r float
Relative tolerance TolAbs: halt if QP-QD <= abs(QP)*TolRel. (default: 0.01)
-q float
Desired objective value QPValue: halt is QP <= QPValue. (default: 0)
-t float
Halts if the solver time (loading time is not counted) exceeds the time given in seconds. (default: infinity)


Train the binary SVM classifier from riply_trn.light, with the regularization constant C=10, bias switched on, verbosity switched off, and save model to svmocas.model:

 svmocas -c 10 -b 1 -v 0 riply_trn.light svmocas.model

Compute the testing error of the classifier stored in svmocas.model with linclassif(1) using testing examples from riply_tst.light and save the predicted labels to riply_tst.pred:

 linclassif -e -o riply_tst.pred riply_tst.light svmocas.model


svmocas was written by Vojtech Franc <[email protected]> and Soeren Sonnenburg <[email protected]>.

This manual page was written by Christian Kastner <[email protected]> for the Debian project (and may be used by others).