# Tag Archives: Interpolation

## VBA procedures for the Numerical Analysis of Tabular Functions

Long time on-line friend Alfred Vachris has recently been converting Fortran code developed through his working career into VBA: I had the opportunity to work at Grumman while going to Graduate School and they gave me a part-time job as … Continue reading

Posted in Coordinate Geometry, Curve fitting, Excel, Fortran, Maths, Newton, UDFs, VBA | | 1 Comment

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

## Spline Interpolation Alternatives

A recent post at Jon Peltier’s Blog looks at an “on-sheet” method of performing linear interpolation on a set of tabular data, and the following comments include a number of alternative ways of carrying out the same process, and also some … Continue reading

Posted in Excel, Maths, Newton, UDFs, VBA | | 7 Comments

## Interpolation Update

The interpolation functions in IP2.xls have been given an overhaul: The linear and quadratic interpolations routines have been modified to accept negative values. All the routines have been modified to convert the table range to an array, rather than using a … Continue reading

Posted in Excel, Maths, Newton, UDFs, VBA | | 4 Comments

## Another update to IP.xls

Following some suggestions from Mike Seymour I have modified my polyline intersection function, and added a new version. The changes are: The data ranges for the new function, IP4(), are entered as four separate ranges, so the X and Y … Continue reading

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