utils.cpp

/***************************************************************************
© Champak Beeravolu Reddy 2016-now

champak.br@gmail.com

This software is governed by the CeCILL license under French law and
abiding by the rules of distribution of free software.  You can  use,
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"http://www.cecill.info".

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***************************************************************************/

/*
 * utils.cpp
 *
 *  Created on: 4 Jan 2016
 *      Author: champost
 */

#include <vector>
#include <string>
#include <cmath>
#include <algorithm>

#include "utils.h"

//	Linearly spaced points between [a,b]
vector<double> linspaced(double a, double b, int n) {
    vector<double> array;
    if ((n == 0) || (n == 1) || (a == b))
    	array.push_back(b);
    else if (n > 1) {
		double step = (b - a) / (n - 1);
		int count = 0;
		while(count < n) {
			array.push_back(a + count*step);
			++count;
		}
    }
    return array;
}


//	Log-spaced points between [a,b] ONLY for (0 < a,b)
vector<double> logspaced(double a, double b, int n) {
    vector<double> array;
    if ((a > 0) && (b > 0)) {
        if ((n == 0) || (n == 1) || (a == b))
        	array.push_back(b);
        else if (n > 1) {
            double step = pow(b/a, 1.0/(n-1));
            int count = 0;
        	while(count < n) {
        		array.push_back(a * pow(step, count));
        		++count;
        	}
        }
    }
    return array;
}


//	Log-spaced points between [a,b] ONLY for (a,b < 0)
vector<double> negLogspaced(double a, double b, int n) {
    vector<double> array;
    double posA = -a, posB = -b;
    if ((posB > 0) && (posA > 0)) {
        if ((n == 0) || (n == 1) || (posB == posA))
        	array.push_back(b);
        else if (n > 1) {
            double step = pow(posA/posB, 1.0/(n-1));
            int count = 0;
        	while(count < n) {
        		array.push_back(-posB * pow(step, count));
        		++count;
        	}
        }
    }
    reverse(array.begin(),array.end());
    return array;
}


void Tokenize(const string& str, vector<string>& tokens, const string& delimiters){
    // Skip delimiters at beginning.
    string::size_type lastPos = str.find_first_not_of(delimiters, 0);
    // Find first "non-delimiter".
    string::size_type pos     = str.find_first_of(delimiters, lastPos);

    while (string::npos != pos || string::npos != lastPos)
    {
        // Found a token, add it to the vector.
        tokens.push_back(str.substr(lastPos, pos - lastPos));
        // Skip delimiters.  Note the "not_of"
        lastPos = str.find_first_not_of(delimiters, pos);
        // Find next "non-delimiter"
        pos = str.find_first_of(delimiters, lastPos);
    }
}


void TrimSpaces(string& str)  {
	// Trim Both leading and trailing spaces
	size_t startpos = str.find_first_not_of(" \t\r\n"); // Find the first character position after excluding leading blank spaces
	size_t endpos = str.find_last_not_of(" \t\r\n"); // Find the first character position from reverse af

	// if all spaces or empty return an empty string
	if(( string::npos == startpos ) || ( string::npos == endpos))
	{
		str = "";
	}
	else
		str = str.substr( startpos, endpos-startpos+1 );
}