Category Archives: UDFs

Alglib/Python spline functions

Continuing from the previous post, the new spreadsheet includes functions for 1D and 2D linear and cubic splines. The basic 1D spline allows  for output of linear splines, or 5 different types of cubic spline, as listed above. Output may … Continue reading

Posted in AlgLib, Excel, Link to Python, Maths, Newton, Numerical integration, UDFs, VBA | Tagged , , , , , , , , , , , | Leave a comment

Alglib/Python linear and non-linear fitting functions

I have updated the Alglib spline-matrix spreadsheet to use the latest Alglib release, using the Python version, in conjunction with the Excel-Python add-in. To use the spreadsheet requires: Python ver 2.7 (or 2.6) Excel-Python Alglib with Python interface In addition … Continue reading

Posted in Excel, UDFs, Newton, VBA, AlgLib, Link to Python | Tagged , , , , , , | 3 Comments

Evaluating text and Integration with Python and ALGLIB

Following the previous post on evaluating mathematical functions entered as text on the spreadsheet, I have now written a spreadsheet with similar functionality using Python functions, and the Excel-Python add-in.  Also included are integration functions using the SciPy Python library, … Continue reading

Posted in AlgLib, Arrays, Excel, Link to Python, Maths, Newton, Numerical integration, NumPy and SciPy, UDFs, VBA | Tagged , , , , , , | 1 Comment

Evaluating text – update

One disadvantage of the spreadsheet style interface is that even simple formulae are difficult to check.  For instance, the deflection of a cantilever loaded at the end is given by: F*L^3/(3*E*I) which is much easier to read than the Excel … Continue reading

Posted in AlgLib, Excel, Maths, Newton, Numerical integration, UDFs, VBA | Tagged , , , , , , , | 2 Comments

Reinforced Concrete – ULS capacity under combined axial load and biaxial bending

I have modified the ULS Design Functions spreadsheet, last presented here, to analyse sections subject to bi-axial bending, and non-symmetrical sections.  The new version makes use of the routines for splitting any section defined by XY coordinates into trapezoidal layers, described … Continue reading

Posted in Beam Bending, Concrete, Excel, Newton, UDFs, VBA | Tagged , , , , , , | 3 Comments