nearest_interp_1d, an Octave code which interpolates a set of data using a piecewise constant interpolant defined by the nearest neighbor criterion.

NEAREST_INTERP_1D needs the R8LIB library. The test also needs the TEST_INTERP library.


The computer code and data files described and made available on this web page are distributed under the MIT license


nearest_interp_1d is available in a C version and a C++ version and a Fortran90 version and a MATLAB version and an Octave version and a Python version.

Related Data and Programs:


newton_interp_1d, a MATLAB code which finds a polynomial interpolant to data using Newton divided differences.

pwl_interp_1d, a MATLAB code which interpolates a set of data using a piecewise linear interpolant.

r8lib, a MATLAB code which contains many utility routines using double precision real (R8) arithmetic.

test_interp, a MATLAB code which defines a number of test problems for interpolation, provided as a set of (x,y) data.


  1. Kendall Atkinson,
    An Introduction to Numerical Analysis,
    Prentice Hall, 1989,
    ISBN: 0471624896,
    LC: QA297.A94.1989.
  2. Philip Davis,
    Interpolation and Approximation,
    Dover, 1975,
    ISBN: 0-486-62495-1,
    LC: QA221.D33
  3. David Kahaner, Cleve Moler, Steven Nash,
    Numerical Methods and Software,
    Prentice Hall, 1989,
    ISBN: 0-13-627258-4,
    LC: TA345.K34.

Source Code:

Last modified on 14 October 2022.