# Category Archives: Arrays

## Setting up UDF Applications

Following a recent comment, this post looks at setting up a user defined function (UDF) on a blank worksheet, using the ConBeamU function as an example. To use a UDF, the VBA code for the function must either be included … Continue reading

Posted in Arrays, Beam Bending, Excel, Finite Element Analysis, Newton, UDFs, VBA | | 1 Comment

## Plotting Freeze-Thaw Data …

… or other irregular cyclic data. Another Eng-Tips question asked how to approximate ice area over a freeze-thaw cycle using a function based on a sine or cosine curve.  The screen-shot below shows three alternatives: Using built in Excel functions requires … Continue reading

Posted in Arrays, Curve fitting, Excel, Maths, Newton, UDFs, VBA | | 1 Comment

## Indexing NumPy arrays with floats …

… now you can’t. I recently updated to the latest version of NumPy (1.12.1), and today I discovered that some of my spreadsheets using NumPy arrays (via xlwings) were returning errors like: IndexError: only integers, slices (`:`), ellipsis (`…`), numpy.newaxis … Continue reading

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

## The meaning of = in Python

In VBA, if you have an array named a and a variant named b, then the statement “b = a” creates a new array b with the same size and values as a.  If the values of either a or b are subsequently changed, the values of the … Continue reading

Posted in Arrays, Excel, Link to Python, NumPy and SciPy, UDFs, VBA | Tagged , , , , , , , , , | 2 Comments

## 3D Frames, axes and stiffness matrices

In the course of adding provision for spring end releases to the 3DFrame spreadsheet, I have also tidied up the code for generating the structure stiffness matrix, and added some documentation to the spreadsheet.  The revised spreadsheet (version 2.02) can … Continue reading

| | 5 Comments

## xlwSciPy 1.09 – update for xlwings 0.10 and Scipy 0.18.1

The xlwSciPy spreadsheet (last presented here) has been updated for the latest version of xlwings and Scipy. The new spreadsheet can be downloaded from: xlScipy-xlw.zip including full open source code. The spreadsheet requires Python, including xlwings, Numpy, Scipy and Pandas … Continue reading

| | 1 Comment

## Non-linear Frame Analysis – Scipy solvers

The frame analysis spreadsheet presented in the previous post has been updated to use the solvers included in the Scipy package.  There is now an option to use either the Cholesky solver, or an iterative sparse solver.  The main advantages of … Continue reading