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SVMOCAS

NAME

svmocas − train a binary linear SVM classifier

SYNOPSIS

svmocas [options] example_file model_file

DESCRIPTION

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.

OPTIONS

A summary of options is included below.

General options:

−h

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)

EXAMPLES

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

SEE ALSO

msvmocas(1), linclassif(1).

AUTHORS

svmocas was written by Vojtech Franc <xfrancv AT cmp DOT felk DOT cvut DOT cz> and Soeren Sonnenburg <Soeren DOT Sonnenburg AT tu-berlin DOT de>.

This manual page was written by Christian Kastner <ckk AT debian DOT org> for the Debian project (and may be used by others).

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