libsvm_file.cpp

#include <shogun/io/LineReader.h>
#include <shogun/io/Parser.h>
#include <shogun/lib/DelimiterTokenizer.h>
#include <shogun/lib/SGVector.h>
#include <shogun/lib/SGSparseVector.h>
#include <shogun/io/SGIO.h>

#include <shogun/base/init.h>

using namespace shogun;

void get_sparse_matrix(
        FILE * file,
        SGSparseVector<float64_t> * &mat_feat,
        int32_t &num_feat,
        int32_t &num_vec,
        SGVector<int32_t> * &multilabel,
        int32_t &num_classes)
{
	char m_delimiter_feat = ':';
	char m_delimiter_label = ',';

	CDelimiterTokenizer * m_whitespace_tokenizer = new CDelimiterTokenizer(
	        true);
	m_whitespace_tokenizer->delimiters[' '] = 1;
	SG_REF(m_whitespace_tokenizer);

	CDelimiterTokenizer * m_delimiter_feat_tokenizer = new CDelimiterTokenizer(
	        true);
	m_delimiter_feat_tokenizer->delimiters[m_delimiter_feat] = 1;
	SG_REF(m_delimiter_feat_tokenizer);

	CDelimiterTokenizer * m_delimiter_label_tokenizer = new CDelimiterTokenizer(
	        true);
	m_delimiter_label_tokenizer->delimiters[m_delimiter_label] = 1;
	SG_REF(m_delimiter_label_tokenizer);

	CDelimiterTokenizer * m_line_tokenizer = new CDelimiterTokenizer(
	        true);
	m_line_tokenizer->delimiters['\n'] = 1;
	SG_REF(m_line_tokenizer);

	CParser * m_parser = new CParser();
	SG_REF(m_parser);

	CLineReader * m_line_reader = new CLineReader(
	        file,
	        m_line_tokenizer);
	SG_REF(m_line_reader);

	SG_SPRINT(">>> Counting number of lines in the file...\n");
	num_vec = 0;

	while (m_line_reader->has_next())
	{
		m_line_reader->skip_line();
		num_vec++;
	}

    m_line_reader->reset();
    SG_SPRINT("<<< Counting lines completed.\n");

    mat_feat = SG_MALLOC(SGSparseVector<float64_t>, num_vec);
    multilabel = SG_MALLOC(SGVector<int32_t>, num_vec);

    SG_UNREF(m_whitespace_tokenizer); SG_UNREF(m_delimiter_feat_tokenizer);
    SG_UNREF(m_delimiter_label_tokenizer); SG_UNREF(m_line_tokenizer);
    SG_UNREF(m_parser); SG_UNREF(m_line_reader); 
}

int main(int argc, char ** argv)
{
	init_shogun_with_defaults();

	sg_io->set_loglevel(MSG_DEBUG);

	FILE * file = fopen("sample.svm", "r");

	int32_t num_feat, num_vec, num_classes;
	SGSparseVector<float64_t> *
	mat_feat;
	SGVector<int32_t> * multilabel;

	get_sparse_matrix(
	        file,
	        mat_feat,
	        num_feat,
	        num_vec,
	        multilabel,
	        num_classes);

	SG_SPRINT("Number of vectors/samples are = %d\n", num_vec);

	exit_shogun();
	return 0;
}