Tag Archives: Cubic spline

AlgLib Spline Functions

Posted on 07/06/2010 by dougaj4

Following earlier posts on cubic splines I have collected the Alglib interpolation routines, and the necessary supporting routines, and written interface functions to allow most of the 1Dspline routines to be called from the spreadsheet.  Since there is a large measure … Continue reading →

Posted in Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , , , , , , | 6 Comments

Cubic Hermitic and Cardinal Splines

Posted on 14/05/2010 by dougaj4

In my previous post on splines I described a quick and dirty approach to adjusting a cubic spline to fit monotonic data, which did not meet with universal approval, so I have followed up Mike Woodhouse’s link: (http://en.wikipedia.org/wiki/Monotone_cubic_interpolation) which gives a … Continue reading →

Posted in Charts, Excel, Maths, UDFs, VBA | Tagged , , , , , , | 8 Comments

Using Cubic Splines in Practice

Posted on 06/05/2010 by dougaj4

I recently had an interesting query from Georg,  a geography student in Germany regarding the use of cubic splines to fit a smooth curve to experimental data.  The graph he sent me is shown below: The cubic spline has produced … Continue reading →

Posted in Charts, Excel, Maths, Newton, UDFs | Tagged , | 9 Comments

Numerical solutions with CSpline

Posted on 05/05/2010 by dougaj4

The CSpline function presented in a previous post  fits a series of cubic polynomial curves to a specified series of points, returning the Y values for listed intermediate X values.  I was recently asked if this could be reversed to … Continue reading →

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Cubic Spline Update

Posted on 16/12/2009 by dougaj4

The previous post in this series presented a User Defined Function (UDF) to fit  a cubic spline to a series of points defined by XY coordinates.  Each segment of the resulting spline is defined by a separate cubic curve, which may be … Continue reading →

Posted in Coordinate Geometry, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , | 1 Comment