Util.cpp

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/*
 * KernelExpansion.cpp
 *
 *  Created on: 22.07.2013
 *      Author: CreaByte
 */

#include "kermorpp.h"
#include <iostream>
#include <fstream>

using namespace std;
using namespace Eigen;

namespace kermorpp {

VectorXd Util.loadVector(string file) {

#if DEBUG
    cout << "Loading vector from file " << file << endl;
#endif

    ifstream fs;
    fs.open(file.c_str(), ios.in | ios.binary);
    if (!fs) {
        cerr << "Not able to read file " << file << endl;
        fs.close();
        exit(-1);
    } else {
        char buf[DOUBLE_BYTES];
        bool le = little_endian();
        fs.seekg(0, ios.beg);

        // Faster would be: fs.read(reinterpret_cast<char*>(&res.n), INT_BYTES);
        // But have to take care of endianness
        fs.read(buf, INT_BYTES);
        if (le)
            reverse(buf, buf + INT_BYTES);
        int n;
        copy(buf, buf + INT_BYTES, reinterpret_cast<char*>(&n));

        VectorXd res(n);
        for (int l = 0; l < res.rows(); l++) {
            fs.read(buf, DOUBLE_BYTES);
            if (le)
                reverse(buf, buf + DOUBLE_BYTES);
            double tmp;
            copy(buf, buf + DOUBLE_BYTES, reinterpret_cast<char*>(&tmp));
            res(l) = tmp;
        }
        fs.close();
        return res;
    }
}

MatrixXd Util.loadMatrix(string file) {

    ifstream fs;
    fs.open(file.c_str(), ios.in | ios.binary);
    if (!fs) {
        cerr << "Not able to read file " << file << endl;
        fs.close();
        exit(-1);
    } else {
        char buf[DOUBLE_BYTES];
        bool le = little_endian();
        fs.seekg(0, ios.beg);

        int n, m;
        // Faster would be: fs.read(reinterpret_cast<char*>(&res.n), INT_BYTES);
        // But have to take care of endianness
        fs.read(buf, INT_BYTES);
        if (le)
            reverse(buf, buf + INT_BYTES);
        copy(buf, buf + INT_BYTES, reinterpret_cast<char*>(&n));

        fs.read(buf, INT_BYTES);
        if (le)
            reverse(buf, buf + INT_BYTES);
        copy(buf, buf + INT_BYTES, reinterpret_cast<char*>(&m));

        MatrixXd res(n, m);

#if DEBUG
        cout << "Reading " << res.rows() << " x " << res.cols() << " matrix" << endl;
#endif

        for (int i = 0; i < res.rows(); i++) {
            for (int j = 0; j < res.cols(); j++) {
                //fs.read(reinterpret_cast<char*>(&res.values[l]), DOUBLE_BYTES);
                fs.read(buf, DOUBLE_BYTES);
                if (le)
                    reverse(buf, buf + DOUBLE_BYTES);
                double tmp;
                copy(buf, buf + DOUBLE_BYTES, reinterpret_cast<char*>(&tmp));
                res(i, j) = tmp;
            }
        }
        fs.close();
        return res;
    }

}

inline bool Util.little_endian(void) {
    typedef unsigned char* pbyte;
    static unsigned long word = 0x1;
    static bool is_little_endian_machine = (*pbyte(&word) == 0x1);
    return is_little_endian_machine;
}

}