Category Archives: UDFs

Using Cubic Splines in Practice

Posted on 06/05/2010 by dougaj4

I recently had an interesting query from Georg,  a geography student in Germany regarding the use of cubic splines to fit a smooth curve to experimental data.  The graph he sent me is shown below: The cubic spline has produced … Continue reading →

Posted in Charts, Excel, Maths, Newton, UDFs | Tagged , | 9 Comments

Numerical solutions with CSpline

Posted on 05/05/2010 by dougaj4

The CSpline function presented in a previous post  fits a series of cubic polynomial curves to a specified series of points, returning the Y values for listed intermediate X values.  I was recently asked if this could be reversed to … Continue reading →

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

Automating chart scale limits

Posted on 28/04/2010 by dougaj4

Edit 22 Mar 2014:  Also see https://newtonexcelbach.wordpress.com/2012/11/25/automating-chart-scale-limits-update/ for improved version with download link, and example of plotting a chart from a formula entered as text. One of the more annoying things about Excel charts is that if you want to … Continue reading →

Posted in Charts, Excel, UDFs, VBA | Tagged , , , , | 8 Comments

Analysis of RC circular sections – theory and code

Posted on 25/04/2010 by dougaj4

The basic tasks involved in analysing the stresses and strains in a reinforced concrete section under combined bending and axial load are: Assuming a horizontal beam with the top of the beam in compression and the bottom in tension Find … Continue reading →

Posted in Beam Bending, Concrete, Excel, Newton, UDFs, VBA | Tagged , , , , , , | Leave a comment

Reinforced concrete elastic analysis; Circular section

Posted on 24/04/2010 by dougaj4

Previous posts have presented the theoretical background to finding stresses and strains in a reinforced concrete section built up of trapezoidal layers and subject to combined bending and axial loads.  A spreadsheet with User Defined Functions (UDFs) and open source code … Continue reading →

Posted in Beam Bending, Concrete, Excel, Newton, UDFs, VBA | Tagged , , , , , , | 10 Comments