Category Archives: UDFs

Alglib/Python spline functions

Continuing from the previous post, the new xl_Spline-Matrix.zip 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