Category Archives: VBA

More circle fitting options with Scipy

Posted on 17/03/2018 by dougaj4

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

Posted on 23/02/2018 by dougaj4

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

Posted on 11/02/2018 by dougaj4

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 , , , , , , , | 7 Comments

Cubic splines with jagged data

Posted on 07/02/2018 by dougaj4

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

Evaluating text with units and finding the neutral axis

Posted on 07/01/2018 by dougaj4

A few weeks ago a comment asked for guidance on finding the moment capacity of a reinforced concrete section.  This post will look at finding the depth of the neutral axis (NA) in a rectangular section, with a single layer of … Continue reading →

Posted in Beam Bending, Concrete, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , , , , , , | 7 Comments