Category Archives: Newton

Finding square roots …

Posted on 06/05/2009 by dougaj4

… to 100 decimal places. Why would anyone want to do that? To solve Project Euler Problem 80: “It is well known that if the square root of a natural number is not an integer, then it is irrational. The … Continue reading →

Posted in Arrays, Excel, Maths, Newton, UDFs, VBA | 2 Comments

Evaluating Pi …

Posted on 12/04/2009 by dougaj4

… to 15 decimal places in one easy step (or not too difficult step). In my previous post one of the examples given of the use of the Gaussian Quadrature function was to evaluate the value of Pi.  Let’s look at … Continue reading →

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

Gaussian Quadrature

Posted on 10/04/2009 by dougaj4

The previous post on integration provided an Excel User Defined Function (UDF) to perform numerical integration using Simpson’s Rule or the Trapezoidal Rule.  A third method is Gaussian Quadrature which is often much more accurate and/or quicker than Simpson’s Rule.  The UDF GaussInt() … Continue reading →

Posted in Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , , | 27 Comments

WolframAlpha

Posted on 10/04/2009 by dougaj4

WolframAlpha is coming! From the link: “Some might say that Mathematica and A New Kind of Science are ambitious projects. But in recent years I’ve been hard at work on a still more ambitious project—called Wolfram|Alpha. And I’m excited to … Continue reading →

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Another update to IP.xls

Posted on 07/04/2009 by dougaj4

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