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// This file is part of libigl, a simple c++ geometry processing library.
//
// Copyright (C) 2013 Alec Jacobson <alecjacobson@gmail.com>
//
// This Source Code Form is subject to the terms of the Mozilla Public License
// v. 2.0. If a copy of the MPL was not distributed with this file, You can
// obtain one at http://mozilla.org/MPL/2.0/.
#ifndef IGL_COLON_H
#define IGL_COLON_H
#include "igl_inline.h"
#include <Eigen/Dense>
namespace igl
{
/// Colon operator like matlab's colon operator. Enumerates values between low
/// and hi with step step.
///
/// @tparam L should be a eigen matrix primitive type like int or double
/// @tparam S should be a eigen matrix primitive type like int or double
/// @tparam H should be a eigen matrix primitive type like int or double
/// @tparam T should be a eigen matrix primitive type like int or double
/// @param[in] low starting value if step is valid then this is *always* the first
/// element of I
/// @param[in] step step difference between sequential elements returned in I,
/// remember this will be cast to template T at compile time. If low<hi
/// then step must be positive. If low>hi then step must be negative.
/// Otherwise I will be set to empty.
/// @param[in] hi ending value, if (hi-low)%step is zero then this will be the last
/// element in I. If step is positive there will be no elements greater
/// than hi, vice versa if hi<low
/// @param[out] I list of values from low to hi with step size step
///
/// \note
/// This should be potentially replaced with eigen's LinSpaced() function
///
/// If step = 1, it's about 5 times faster to use:
/// X = Eigen::VectorXi::LinSpaced(n,0,n-1);
/// than
/// X = igl::colon<int>(0,n-1);
///
template <typename L,typename S,typename H,typename T>
IGL_INLINE void colon(
const L low,
const S step,
const H hi,
Eigen::Matrix<T,Eigen::Dynamic,1> & I);
/// Colon operator like matlab's colon operator. Enumerates values between low
/// and hi with unit step.
///
/// @tparam L should be a eigen matrix primitive type like int or double
/// @tparam H should be a eigen matrix primitive type like int or double
/// @tparam T should be a eigen matrix primitive type like int or double
/// @param[in] low starting value if step is valid then this is *always* the first
/// element of I
/// @param[in] step step difference between sequential elements returned in I,
/// remember this will be cast to template T at compile time. If low<hi
/// then step must be positive. If low>hi then step must be negative.
/// Otherwise I will be set to empty.
/// @param[in] hi ending value, if (hi-low)%step is zero then this will be the last
/// element in I. If step is positive there will be no elements greater
/// than hi, vice versa if hi<low
/// @param[out] I list of values from low to hi with step size step
template <typename L,typename H,typename T>
IGL_INLINE void colon(
const L low,
const H hi,
Eigen::Matrix<T,Eigen::Dynamic,1> & I);
/// @private
///
/// Hiding this from doxygen because it's messing up the indentation.
///
/// Colon operator like matlab's colon operator. Enumerates values between low
/// and hi with unit step.
///
/// @tparam T should be a eigen matrix primitive type like int or double
/// @tparam L should be a eigen matrix primitive type like int or double
/// @tparam H should be a eigen matrix primitive type like int or double
/// @param[in] low starting value if step is valid then this is *always* the first
/// element of I
/// @param[in] step step difference between sequential elements returned in I,
/// remember this will be cast to template T at compile time. If low<hi
/// then step must be positive. If low>hi then step must be negative.
/// Otherwise I will be set to empty.
/// @param[in] hi ending value, if (hi-low)%step is zero then this will be the last
/// element in I. If step is positive there will be no elements greater
/// than hi, vice versa if hi<low
/// @return list of values from low to hi with step size step
template <typename T,typename L,typename H>
IGL_INLINE Eigen::Matrix<T,Eigen::Dynamic,1> colon(
const L low,
const H hi);
}
#ifndef IGL_STATIC_LIBRARY
# include "colon.cpp"
#endif
#endif