Category Archives: Charts

Charting a Mathematical Function with Defined Names

Posted on 15/12/2010 by dougaj4

This post is a compilation of information from Stephen Bullen, Jan Karel Pieterse, and George Lungu.  To quote JKP “When doing mathematics, wouldn’t it be nice if we could type an equation into a cell in Excel and immediately see … Continue reading →

Posted in Arrays, Charts, Excel, Maths | Tagged , , , , | 7 Comments

Faster Ferns

Posted on 03/10/2010 by dougaj4

I have modified the fern input parameters in the spreadsheet presented in the previous post to match the layout used by Barnsley and others, so that examples such as those given at the Wikipedia article can be entered directly.  The … Continue reading →

Posted in Arrays, Charts, Charts, Drawing, Excel, Maths, Newton, VBA | Tagged , , , | 4 Comments

Plotting Ferns

Posted on 27/09/2010 by dougaj4

Over at Daily-Dose-of-Excel mrt has posted an interesting VBA version of a Matlab program that used an Iterated Transfer Function to plot a graph resembling a fern.  The original Matlab code came from Dr Tom Wood, and Michael’s VBA version works just fine, … Continue reading →

Posted in Arrays, Charts, Drawing, Excel, Maths, Newton, VBA | Tagged , , , , | 5 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