Category Archives: Maths

Precise Angles and XNumbers

Posted on 28/01/2013 by dougaj4

Further to comments by Georg under: The angle between two vectors, in 2D or 3D I have added four alternative ways of calculating the angle between two 3D vectors to the VectorFunc spreadsheet.  The new version can be downloaded from: http://interactiveds.com.au/software/VectorFunc.xlsb. … Continue reading →

Posted in Coordinate Geometry, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , | Leave a comment

New Release Alglib Library

Posted on 22/01/2013 by dougaj4

The Alglib Numerical Analysis Library has just been updated.  For full details of the changes see: http://www.alglib.net/arcnews.php#date_18_01_2013 , but the significant change for routines linking to my spreadsheets is that the sparse solver  has been significantly improved and now successfully solves problems … Continue reading →

Posted in AlgLib, Excel, Finite Element Analysis, Link to dll, Maths, Newton | Tagged , , , | Leave a comment

Defining beam orientation in 3D

Posted on 19/01/2013 by dougaj4

The principal axes of a beam (or any 2D closed shape) are defined as the axes along which an applied load will not cause any deflection in the transverse direction.  In mathematical terms, if the beam cross-section is defined in the … Continue reading →

Posted in Beam Bending, Coordinate Geometry, Frame Analysis, Maths, Newton | Tagged , , , , | Leave a comment

The angle between two vectors, in 2D or 3D

Posted on 12/01/2013 by dougaj4

Finding the angle between two lines in 2D is easy, just find the angle of each line with the x-axis from the slope of the line and take the difference.  In 3D it is not so obvious, but it can … Continue reading →

Posted in Coordinate Geometry, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , , | 9 Comments

Tanh-Sinh Quadrature V4.0

Posted on 03/01/2013 by dougaj4

Since last September Graeme Dennes has continued work on his Tanh-Sinh Quadrature spreadsheet, and has recently released Version 4.0, which can be downloaded from: Tanh-Sinh. As usual, the download includes full open-source code and extensive documentation. The new version includes routines … Continue reading →

Posted in Excel, Maths, Newton, Numerical integration, UDFs, VBA | Tagged , , , , | 6 Comments