Chebyshev points of the first kind. The Chebyshev points of the first kind are the points ``cos(x)``, where ``x = [pi*(k + .5)/npts for k in range(npts)]``. Parameters ---------- npts : int Number of sample points desired. Returns ------- pts : ndarray
(npts)
| 1918 | |
| 1919 | |
| 1920 | def chebpts1(npts): |
| 1921 | """ |
| 1922 | Chebyshev points of the first kind. |
| 1923 | |
| 1924 | The Chebyshev points of the first kind are the points ``cos(x)``, |
| 1925 | where ``x = [pi*(k + .5)/npts for k in range(npts)]``. |
| 1926 | |
| 1927 | Parameters |
| 1928 | ---------- |
| 1929 | npts : int |
| 1930 | Number of sample points desired. |
| 1931 | |
| 1932 | Returns |
| 1933 | ------- |
| 1934 | pts : ndarray |
| 1935 | The Chebyshev points of the first kind. |
| 1936 | |
| 1937 | See Also |
| 1938 | -------- |
| 1939 | chebpts2 |
| 1940 | |
| 1941 | Notes |
| 1942 | ----- |
| 1943 | |
| 1944 | .. versionadded:: 1.5.0 |
| 1945 | |
| 1946 | """ |
| 1947 | _npts = int(npts) |
| 1948 | if _npts != npts: |
| 1949 | raise ValueError("npts must be integer") |
| 1950 | if _npts < 1: |
| 1951 | raise ValueError("npts must be >= 1") |
| 1952 | |
| 1953 | x = 0.5 * np.pi / _npts * np.arange(-_npts+1, _npts+1, 2) |
| 1954 | return np.sin(x) |
| 1955 | |
| 1956 | |
| 1957 | def chebpts2(npts): |