Author Archives: dougaj4

Significant Figures

Posted on 28/12/2008 by dougaj4

Excel does not provide any built in functions to round values to a specified number of significant figures.  The UDF below, recently posted at the Eng-Tips forum, will do the job: Public Function sigfig(my_num, digits) As Double Dim num_places As Integer … Continue reading →

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

Anniversaries

Posted on 27/12/2008 by dougaj4

It has just come to my notice that this year I missed my half millionth Birthhour, which was also my 30 millionth Birthminute. Luckily I still have plenty of time to prepare for my 2 billionth Birthsecond. To avoid missing … Continue reading →

Posted in Excel, UDFs, VBA | Tagged , , , , | 3 Comments

Solving simultaneous equations – Fortran dll

Posted on 20/12/2008 by dougaj4

The file simultaneous.zip has been modified to allow access to a Fortran simultaneous equation routine, compiled as a dll.  The original file was posted in solving simultaneous equations.  The advantages of a compiled routine include: Much better performance Greater precision through … Continue reading →

Posted in Arrays, Fortran, Link to dll, Maths, UDFs, VBA | Tagged , , , , , | 3 Comments

Physics Puzzle

Posted on 16/12/2008 by dougaj4

The question below was set in a VCE (high school exam) physics exam in Victoria Australia.  After the exam the question was discussed by a number of physics experts who failed to reach a concensus on what the correct answer … Continue reading →

Posted in Newton | Tagged , , , | 11 Comments

Trigonometric Functions – dll

Posted on 11/12/2008 by dougaj4

I have converted the trigonometric functions presented in this earlier post into a Fortran dll.  The dll and associated spreadsheet and add-in files can be downloaded from here. This file and the associated file Trig.dll provide trigonometric and hyperbolic functions not … Continue reading →

Posted in Excel, Link to dll, Maths, Newton, UDFs | Tagged , , , , , , | 2 Comments