Category Archives: Maths

Section Properties from Layers

Posted on 19/03/2008 by dougaj4

An alternative to finding the section properties of irregular polygons from the coordinates of the corners is to divide the shape into rectangular or trapezoidal layers.  The properties of the shape may then be found by simply summing the properties … Continue reading →

Posted in Maths, Newton, Uncategorized | Tagged , , , , | 1 Comment

Section Properties from Coordinates

Posted on 09/03/2008 by dougaj4

The area of irregular closed polygons defined by coordinates may be conveniently calculated by summing the areas of adjacent trapeziums, as shown below.   The area of each trapezium is calculated from the X axis.  Note that with the apex coordinates … Continue reading →

Posted in Maths, Newton | Tagged , , , , | 2 Comments

Trigonometric Functions in VBA

Posted on 23/02/2008 by dougaj4

Deep within the bowels of the Microsoft on-line help can be found: http://msdn2.microsoft.com/en-us/library/csfk8t62(VS.85).aspx which lists  the derivation of trigonometric functions not provided by VBA.  Not included in this list is ATan2(), which is strange because this is the one trigonometric … Continue reading →

Posted in Excel, Maths, UDFs | Tagged | 7 Comments