Tag Archives: Cubic spline

Update to AL-Spline-Matrix

Posted on November 28, 2017 by

The AL-Spline-Matrix spreadsheet contains a large number of VBA user defined functions (UDFs) performing spline fitting and matrix operations, using the free and open source ALGLIB library. It was recently pointed out that the Excel interface code for the CSplineFitCW1da … Continue reading →

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

Daily Download 22: Splines and Curves

Posted on October 8, 2012 by

Since it was first published in 2009 my CSpline function has been the most popular download from this site.  CSpline (and various associated functions) is used to fit a series of cubic curves through specified points, allowing interpolation along a smooth … Continue reading →

Posted in AlgLib, Beam Bending, Charts, Charts, Coordinate Geometry, Excel, Newton, Numerical integration, UDFs, VBA | Tagged , , , , , , , , | 7 Comments

Alglib Spline Functions 1.32

Posted on July 23, 2012 by

Following a comment to AlgLib Spline Functions, the AL-Spline-Matrix spreadsheets have been updated, and may be downloaded from AL-Spline-Matrix03 for Excel 2003 and earlier and AL-Spline-Matrix07 for Excel 2007 and 2010.

Posted in AlgLib, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , , , , , , | Leave a comment

Revision to CSpline2.xls

Posted on November 11, 2010 by

It was recently reported to me that the cubic spline spreadsheet CSpline2.xls (posted here) was crashing on loading in Excel 2003.  It seems that the problem was with the ChartSpline function, and that there are no problems if this function is … Continue reading →

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

SplineBeam update

Posted on June 20, 2010 by

Previous SplineBeam post I have modified the SplineBeam spreadsheet to allow input of a single span (simply supported or with end constraints), and to optionally allow input of the position of intermediate nodes, rather than dividing each span into equal segment lengths.  This … Continue reading →

Posted in Arrays, Beam Bending, Excel, Frame Analysis, Newton, UDFs, VBA | Tagged , , , , | 1 Comment

AlgLib Spline Functions

Posted on June 7, 2010 by

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 May 14, 2010 by

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