Category Archives: VBA

Beam geometric non-linear effects

A quick and convenient way to allow for the effect of deformations on the behaviour of beams and columns under axial load is to adjust the beam stiffness matrix, so that the calculated deflections are in equilibrium with the applied … Continue reading

Posted in Beam Bending, Excel, Finite Element Analysis, Frame Analysis, Newton, UDFs, VBA | Tagged , , , , , , | 2 Comments

xlwSciPy update for Python 3

The xlwSciPy spreadsheet allows a wide variety of the science and maths functions in the Python Numpy and Scipy libraries to be called directly from Excel.  The spreadsheet has now been updated for use with Python 3.  The spreadsheet and … Continue reading

Posted in Coordinate Geometry, Differential Equations, Excel, Link to Python, Maths, Newton, Numerical integration, NumPy and SciPy, Python Pandas, UDFs, VBA, xlwings | Tagged , , , , , , | Leave a comment

Plotting Charts With Gaps …

“How do you get VB6 to initialize doubles with +infinity, -infinity and NaN”… and various sorts of Not a Number. Back in 2012 (When is an xy chart not an xy chart) I concluded that it was not possible to … Continue reading

Posted in Arrays, Charts, Charts, Excel, UDFs, VBA | Tagged , , , | 5 Comments

More circle fitting options with Scipy

A comment on the first post on this topic found that the method used did not work well for short arcs of large radius circles.  An example of the problem can be seen in the screen shots below: The function … Continue reading

Posted in Coordinate Geometry, Curve fitting, Excel, Link to Python, Maths, Newton, NumPy and SciPy, UDFs, VBA, xlwings | Tagged , , , , , , , | Leave a comment

More Python rotation functions

The code described in the previous post includes a Python function that rotates 3D coordinates by an angle defined with two vectors, using Rodrigue’s Rotation.  I have now added this function to the IP2_py spreadsheet, where it is used in the … Continue reading

Posted in Coordinate Geometry, Drawing, Excel, Link to Python, Maths, Newton, NumPy and SciPy, UDFs, VBA, xlwings | Tagged , , , , , , , , | Leave a comment

Fitting 3D circles to scattered points

Following a comment at update-to-glob_to_loc3-and-loc_to_glob3-functions, I have modified the Python code at the linked site, so it can be run from Excel, via xlwings.  The spreadsheet described below, and the associated Python code, can be download from: 3DCirc.zip The original … Continue reading

Posted in Coordinate Geometry, Excel, Link to Python, Maths, Newton, NumPy and SciPy, UDFs, VBA, xlwings | Tagged , , , , , , , | 5 Comments

Cubic splines with jagged data

A cubic spline provides a good approximation to a smooth curve, and alternative versions are available for free download (see Daily Download 22: Splines and Curves, Update to AL-Spline-Matrix, and xlwSciPy 1.09 – update for xlwings 0.10 and Scipy 0.18.1), but if … Continue reading

Posted in Arrays, Beam Bending, Concrete, Curve fitting, Excel, Newton, UDFs, VBA | Tagged , , , , , , | 2 Comments