---
name: "QwtSplineCurveFitter"
section: "3"
platform: "linux"
package: "libqwt-doc"
version: "6.1.4-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/QwtSplineCurveFitter"
---

# QwtSplineCurveFitter(3)

A curve fitter using cubic splines.

## NAME

QwtSplineCurveFitter - A curve fitter using cubic splines.

## SYNOPSIS

`#include <qwt_curve_fitter.h>`

Inherits **QwtCurveFitter**.

### Public Types

enum **FitMode** { **Auto**, **Spline**, **ParametricSpline** }\

### Public Member Functions

**QwtSplineCurveFitter** ()\
 Constructor.  virtual **~QwtSplineCurveFitter** ()\
 Destructor.  void **setFitMode** (**FitMode**)\
 **FitMode** **fitMode** () const\
 void **setSpline** (const **QwtSpline** &)\
 const **QwtSpline** & **spline** () const\
 **QwtSpline** & **spline** ()\
 void **setSplineSize** (int)\
 int **splineSize** () const\
 virtual QPolygonF **fitCurve** (const QPolygonF &) const\

### Additional Inherited Members

## Detailed Description

A curve fitter using cubic splines.

## Member Enumeration Documentation

### enum QwtSplineCurveFitter::FitMode

Spline type The default setting is Auto

**See also:**

**setFitMode()**, **FitMode()**

**Enumerator**

- *Auto*

  *Use the default spline algorithm for polygons with increasing x values ( p\[i-1\] \< p\[i\] ), otherwise use a parametric spline algorithm.*

- *Spline*

  *Use a default spline algorithm.*

- *ParametricSpline*

  *Use a parametric spline algorithm.*

## Member Function Documentation

### QPolygonF QwtSplineCurveFitter::fitCurve (const QPolygonF & points) const` [virtual]`

*Find a curve which has the best fit to a series of data points*

**Parameters:**

*points Series of data points*

**Returns:**

*Curve points*

*Implements* **QwtCurveFitter***.*

### QwtSplineCurveFitter::FitMode QwtSplineCurveFitter::fitMode () const

**Returns:**

*Mode representing a spline algorithm*

**See also:**

**setFitMode()**

### void QwtSplineCurveFitter::setFitMode (FitMode mode)

*Select the algorithm used for building the spline*

**Parameters:**

*mode Mode representing a spline algorithm*

**See also:**

**fitMode()**

### void QwtSplineCurveFitter::setSpline (const QwtSpline & spline)

*Assign a spline*

**Parameters:**

*spline Spline*

**See also:**

**spline()**

### void QwtSplineCurveFitter::setSplineSize (int splineSize)

*Assign a spline size ( has to be at least 10 points )*

**Parameters:**

*splineSize Spline size*

**See also:**

**splineSize()**

### const QwtSpline & QwtSplineCurveFitter::spline () const

**Returns:**

*Spline*

**See also:**

**setSpline()**

### QwtSpline & QwtSplineCurveFitter::spline ()

**Returns:**

*Spline*

**See also:**

**setSpline()**

### int QwtSplineCurveFitter::splineSize () const

**Returns:**

*Spline size*

**See also:**

**setSplineSize()**

## Author

*Generated automatically by Doxygen for Qwt User's Guide from the source code.*