**pwl_approx_1d_test**,
a MATLAB code which
calls pwl_approx_1d(), which
defines and evaluates a piecewise linear function, using NC "control points",
which approximates a set of ND data points (x(i),y(i)).

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

pwl_approx_1d, a MATLAB code which approximates a set of data using a piecewise linear function.

- pwl_approx_1d_test.m, calls all the tests;
- pwl_approx_1d_test.sh, runs all the tests;
- pwl_approx_1d_test.txt, the output file.

- pwl_approx_1d_test01.m, plots a piecewise linear interpolant to the original data, and the piecewise linear approximant.

**pwl_approx_1d_test01()** uses nc evenly spaced control points to approximate
a set of nd data values.

- p01_pwl_02_16.png, a plot of the piecewise linear approximant with 2 control points approximating 16 data values for problem p01;
- p01_pwl_04_16.png, a plot of the piecewise linear approximant with 4 control points approximating 16 data values for problem p01;
- p01_pwl_08_16.png, a plot of the piecewise linear approximant with 8 control points approximating 16 data values for problem p01;
- p01_pwl_16_16.png, a plot of the piecewise linear approximant with 16 control points approximating 16 data values for problem p01;
- p01_pwl_02_64.png, a plot of the piecewise linear approximant with 2 control points approximating 64 data values for problem p01;
- p01_pwl_04_64.png, a plot of the piecewise linear approximant with 4 control points approximating 64 data values for problem p01;
- p01_pwl_08_64.png, a plot of the piecewise linear approximant with 8 control points approximating 64 data values for problem p01;
- p01_pwl_16_64.png, a plot of the piecewise linear approximant with 16 control points approximating 64 data values for problem p01;

- p02_pwl_02_16.png, a plot of the piecewise linear approximant with 2 control points approximating 16 data values for problem p02;
- p02_pwl_04_16.png, a plot of the piecewise linear approximant with 4 control points approximating 16 data values for problem p02;
- p02_pwl_08_16.png, a plot of the piecewise linear approximant with 8 control points approximating 16 data values for problem p02;
- p02_pwl_16_16.png, a plot of the piecewise linear approximant with 16 control points approximating 16 data values for problem p02;
- p02_pwl_02_64.png, a plot of the piecewise linear approximant with 2 control points approximating 64 data values for problem p02;
- p02_pwl_04_64.png, a plot of the piecewise linear approximant with 4 control points approximating 64 data values for problem p02;
- p02_pwl_08_64.png, a plot of the piecewise linear approximant with 8 control points approximating 64 data values for problem p02;
- p02_pwl_16_64.png, a plot of the piecewise linear approximant with 16 control points approximating 64 data values for problem p02;

- p03_pwl_02_16.png, a plot of the piecewise linear approximant with 2 control points approximating 16 data values for problem p03;
- p03_pwl_04_16.png, a plot of the piecewise linear approximant with 4 control points approximating 16 data values for problem p03;
- p03_pwl_08_16.png, a plot of the piecewise linear approximant with 8 control points approximating 16 data values for problem p03;
- p03_pwl_16_16.png, a plot of the piecewise linear approximant with 16 control points approximating 16 data values for problem p03;
- p03_pwl_02_64.png, a plot of the piecewise linear approximant with 2 control points approximating 64 data values for problem p03;
- p03_pwl_04_64.png, a plot of the piecewise linear approximant with 4 control points approximating 64 data values for problem p03;
- p03_pwl_08_64.png, a plot of the piecewise linear approximant with 8 control points approximating 64 data values for problem p03;
- p03_pwl_16_64.png, a plot of the piecewise linear approximant with 16 control points approximating 64 data values for problem p03;

- p04_pwl_02_16.png, a plot of the piecewise linear approximant with 2 control points approximating 16 data values for problem p04;
- p04_pwl_04_16.png, a plot of the piecewise linear approximant with 4 control points approximating 16 data values for problem p04;
- p04_pwl_08_16.png, a plot of the piecewise linear approximant with 8 control points approximating 16 data values for problem p04;
- p04_pwl_16_16.png, a plot of the piecewise linear approximant with 16 control points approximating 16 data values for problem p04;
- p04_pwl_02_64.png, a plot of the piecewise linear approximant with 2 control points approximating 64 data values for problem p04;
- p04_pwl_04_64.png, a plot of the piecewise linear approximant with 4 control points approximating 64 data values for problem p04;
- p04_pwl_08_64.png, a plot of the piecewise linear approximant with 8 control points approximating 64 data values for problem p04;
- p04_pwl_16_64.png, a plot of the piecewise linear approximant with 16 control points approximating 64 data values for problem p04;

- p05_pwl_02_16.png, a plot of the piecewise linear approximant with 2 control points approximating 16 data values for problem p05;
- p05_pwl_04_16.png, a plot of the piecewise linear approximant with 4 control points approximating 16 data values for problem p05;
- p05_pwl_08_16.png, a plot of the piecewise linear approximant with 8 control points approximating 16 data values for problem p05;
- p05_pwl_16_16.png, a plot of the piecewise linear approximant with 16 control points approximating 16 data values for problem p05;
- p05_pwl_02_64.png, a plot of the piecewise linear approximant with 2 control points approximating 64 data values for problem p05;
- p05_pwl_04_64.png, a plot of the piecewise linear approximant with 4 control points approximating 64 data values for problem p05;
- p05_pwl_08_64.png, a plot of the piecewise linear approximant with 8 control points approximating 64 data values for problem p05;
- p05_pwl_16_64.png, a plot of the piecewise linear approximant with 16 control points approximating 64 data values for problem p05;

- p06_pwl_02_16.png, a plot of the piecewise linear approximant with 2 control points approximating 16 data values for problem p06;
- p06_pwl_04_16.png, a plot of the piecewise linear approximant with 4 control points approximating 16 data values for problem p06;
- p06_pwl_08_16.png, a plot of the piecewise linear approximant with 8 control points approximating 16 data values for problem p06;
- p06_pwl_16_16.png, a plot of the piecewise linear approximant with 16 control points approximating 16 data values for problem p06;
- p06_pwl_02_64.png, a plot of the piecewise linear approximant with 2 control points approximating 64 data values for problem p06;
- p06_pwl_04_64.png, a plot of the piecewise linear approximant with 4 control points approximating 64 data values for problem p06;
- p06_pwl_08_64.png, a plot of the piecewise linear approximant with 8 control points approximating 64 data values for problem p06;
- p06_pwl_16_64.png, a plot of the piecewise linear approximant with 16 control points approximating 64 data values for problem p06;

- p07_pwl_02_16.png, a plot of the piecewise linear approximant with 2 control points approximating 16 data values for problem p07;
- p07_pwl_04_16.png, a plot of the piecewise linear approximant with 4 control points approximating 16 data values for problem p07;
- p07_pwl_08_16.png, a plot of the piecewise linear approximant with 8 control points approximating 16 data values for problem p07;
- p07_pwl_16_16.png, a plot of the piecewise linear approximant with 16 control points approximating 16 data values for problem p07;
- p07_pwl_02_64.png, a plot of the piecewise linear approximant with 2 control points approximating 64 data values for problem p07;
- p07_pwl_04_64.png, a plot of the piecewise linear approximant with 4 control points approximating 64 data values for problem p07;
- p07_pwl_08_64.png, a plot of the piecewise linear approximant with 8 control points approximating 64 data values for problem p07;
- p07_pwl_16_64.png, a plot of the piecewise linear approximant with 16 control points approximating 64 data values for problem p07;

- p08_pwl_02_16.png, a plot of the piecewise linear approximant with 2 control points approximating 16 data values for problem p08;
- p08_pwl_04_16.png, a plot of the piecewise linear approximant with 4 control points approximating 16 data values for problem p08;
- p08_pwl_08_16.png, a plot of the piecewise linear approximant with 8 control points approximating 16 data values for problem p08;
- p08_pwl_16_16.png, a plot of the piecewise linear approximant with 16 control points approximating 16 data values for problem p08;
- p08_pwl_02_64.png, a plot of the piecewise linear approximant with 2 control points approximating 64 data values for problem p08;
- p08_pwl_04_64.png, a plot of the piecewise linear approximant with 4 control points approximating 64 data values for problem p08;
- p08_pwl_08_64.png, a plot of the piecewise linear approximant with 8 control points approximating 64 data values for problem p08;
- p08_pwl_16_64.png, a plot of the piecewise linear approximant with 16 control points approximating 64 data values for problem p08;