Category Archives: Excel

Calling Numpy polynomial functions from Excel

Posted on 31/10/2022 by dougaj4

The Numpy polynomial related function discussed in recent posts can now be downloaded from: py_Numpy.zip The download file includes Python code and a sample spreadsheet. Required installed software is Python, Numba and pyxll to call the code from Excel. Some … Continue reading →

Posted in Curve fitting, Excel, Link to Python, Maths, NumPy and SciPy, PyXLL, UDFs | Tagged , , , , | 1 Comment

Solving cubic equations – background and timing

Posted on 25/10/2022 by dougaj4

For more information on the polynomial functions, including quartic and higher order solvers, see: Solving Quadratic, Cubic, Quartic and higher order equations; examples Re-reading the Wikipedia article on solving cubic equations, I noticed that the trigonometrical solution for finding 3 real … Continue reading →

Posted in Excel, Link to Python, Maths, Newton, NumPy and SciPy, PyXLL, UDFs, VBA | Tagged , , , , , , , , , | Leave a comment

Working with Python polynomials from Excel

Posted on 22/10/2022 by dougaj4

Python polynomial functions have several features that require manipulation of data passed from Excel: I have written 3 short Python functions to deal with passing arrays of complex numbers from and to Excel, using pyxll, or within Python code to … Continue reading →

Posted in Arrays, Excel, Link to Python, PyXLL, UDFs | Tagged , , , , , , , , , | Leave a comment

A Match Function Bug …

Posted on 08/10/2022 by dougaj4

… or at least, a non-intuitive feature of the MATCH function, that may give inconsistent results. This post is based on a discussion at EngTips. The problem under discussion was to find the number of the first and last rows … Continue reading →

Posted in Arrays, Excel | Tagged , , , | 3 Comments

3D plots with the latest Matplotlib

Posted on 30/09/2022 by dougaj4

Installing Python on a new computer, I found I had to downgrade Matplotlib to release 3.5.2 to get my 3D plotting functions to work. Further investigation found that the problem was the Axes3D function. Changing:     ax = axes3d.Axes3D(fig)to: … Continue reading →

Posted in Animation, Coordinate Geometry, Drawing, Excel, Link to Python, Newton, NumPy and SciPy, PyXLL, UDFs | Tagged , , , , , , | 4 Comments