IDL Analyst Reference Guide: Interpolation and Approximation

Interpolation and Approximation Routines

Cubic Spline Interpolation

IMSL_CSINTERP—Derivative end conditions.

IMSL_CSSHAPE—Shape preserving.

B-spline Interpolation

IMSL_BSINTERP—One-dimensional and two-dimensional interpolation.

IMSL_BSKNOTS—Knot sequence given interpolation data.

B-spline and Cubic Spline Evaluation and Integration

IMSL_SPVALUE—Evaluation and differentiation.

IMSL_SPINTEG—Integration.

Least-squares Approximation and Smoothing

IMSL_FCNLSQ—General functions.

IMSL_BSLSQ—Splines with fixed knots.

IMSL_CONLSQ—Constrained spline fit.

IMSL_CSSMOOTH—Cubic-smoothing spline.

IMSL_SMOOTHDATA1D—Smooth one-dimensional data by error detection.

Scattered Data Interpolation

IMSL_SCAT2DINTERP—Akima's surface-fitting method.

IMSL_RADBF—Computes a fit using radial-basis functions.

IMSL_RADBE—Evaluates a radial-basis fit.

  IDL Online Help (March 06, 2007)