Category Archives: Maths

Function roots with the Inverse Quadratic Method

Posted on 31/03/2010 by dougaj4

An earlier post presented various methods for finding the roots of polynomial functions based on the use of linear interpolation.  It is sometimes advantageous to use a quadratic interpolation function, and methods using this approach will be presented in this and following … Continue reading →

Posted in Excel, Maths, UDFs, VBA | Tagged , , , , | 5 Comments

Pie charts all the way down

Posted on 07/02/2010 by dougaj4

xkcd post number 688 shows charts of the proportion of black ink in the charts in xkcd post number 688, and it has in the chart on the right a plans of the locations of the charts in xkcd post … Continue reading →

Posted in Maths, Newton | Tagged , , | 1 Comment

Hello World (again)

Posted on 02/02/2010 by dougaj4

Over at Daily Dose of Excel Dick has been asking for suggestions for excellent training, to which Jan Karel Pietersen replied that training should be relevant to the task at hand, and that “hello world” examples are useless. John Walkenbach responded … Continue reading →

Posted in Excel, Maths, UDFs, VBA | Tagged , , , , | 2 Comments

Perfect Anniversaries

Posted on 13/01/2010 by dougaj4

The young author of  The Math Less Travelled has just celebrated his 28 birthday, noting that 28 is a perfect number.  He laments that since the next perfect number is 496, it is most unlikely that he will see another perfect … 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