Author Archives: dougaj4

Daily Download 23: Trigonometric Functions in VBA and Fortran

Posted on 09/10/2012 by dougaj4

The trigonometric functions provided in Excel omit some functions, and the functions provided in VBA are still more restricted.  Notably VBA does not provide an ATan2 function, which is required to define an angle over a full 360 degree range, based on X, … Continue reading →

Posted in Coordinate Geometry, Excel, Link to dll, Maths, Newton, UDFs, VBA | Tagged , , , , , | 8 Comments

Daily Download 22: Splines and Curves

Posted on 08/10/2012 by dougaj4

Since it was first published in 2009 my CSpline function has been the most popular download from this site.  CSpline (and various associated functions) is used to fit a series of cubic curves through specified points, allowing interpolation along a smooth … Continue reading →

Posted in AlgLib, Beam Bending, Charts, Charts, Coordinate Geometry, Excel, Newton, Numerical integration, UDFs, VBA | Tagged , , , , , , , , | 7 Comments

Daily Download 21: Assorted Solvers

Posted on 08/10/2012 by dougaj4

Today’s download starts with some simple linear interpolation methods used to solve polynomial equations, leading on to more sophisticated methods using quadratic or inverse quadratic interpolation. Also included is a solver for differential equations using the Cash-Karp Method, which is … Continue reading →

Posted in AlgLib, Beam Bending, Differential Equations, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , , , , , , | Leave a comment

Daily Download 20: Section Properties

Posted on 06/10/2012 by dougaj4

The download spreadsheets today provide functions to find section properties of shapes either defined by coordinates or selected from a list of shape types.  The section properties found are: area, first and second moments of area about the X and Y … Continue reading →

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

Daily Download 19: Solving polynomials

Posted on 06/10/2012 by dougaj4

Today’s download provides analytic solutions to polynomial equations up to fourth order (that is quadratic, cubic and quartic equations) and an iterative method to solve equations of higher order.  All these functions are found in the download file: http://interactiveds.com.au/software/Polynomial.zip The … Continue reading →

Posted in Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , , , , | 1 Comment