Category Archives: Maths

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

Complex Numbers and Solving Quartic Polynomial Equations

Posted on 19/09/2010 by dougaj4

It was recently pointed out to me that the User Defined Function (UDF) for solving quartic polynomial equations presented in this post returned an error for some input values.  In tracking down the source of the error I decided that it … Continue reading →

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

Eval.xls and the ALGLIB integration functions.

Posted on 11/09/2010 by dougaj4

In a comment on a previous post on numerical integration I mentioned that I might implement the ALGLIB integration functions using the same technique, that is using the VBA Evaluate function to evaluate functions entered as text in the spreadsheet.  Well … Continue reading →

Posted in AlgLib, Excel, Maths, Newton, Numerical integration, UDFs, VBA | Tagged , , , , | 4 Comments

Drawing a Buckyball in Excel

Posted on 04/09/2010 by dougaj4

Since, according to Google, it is the 25th anniversary of the Buckyball, I thought I would draw one in Excel. A quick search found a list of coordinates here: Chemistry resources The problem then was, how to connect them.  The information … Continue reading →

Posted in Drawing, Excel, Maths | Tagged , | 10 Comments