## Modeling atomic diffusion and polymerization – coding an Excel animated model

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Science, Engineering, Games in Excel & VBA

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2019-07-11

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2019-02-06

This is a model I made quite some years back to model the stability of an air compressor driven by an electric motor. The purpose was also to try to select the motor parameters, transmission ratios, energy loss in the flexible couple. I will make the Excel file available at a later date.Continue Reading

2012-03-23

This is the second post on Excel speed. This has serious implications in creating usable Excel animations. The first part benchmarked the calculation speed of Excel 2003 versus Excel 2007 for various size arrays of formulas. This part analyzes the effect of formula complexity on the spreadsheet speed. About the speed of animated models in MS Excel – part #2Continue Reading

2012-03-20

This post considers several aspects about improving the speed of spreadsheets in both MS Excel 2003 and 2007. It has significant effects on animations in MS Excel. In this first part, a “stopwatch” macro is described which, when incorporated in any of calculation loop, can measure the frequency your loop is executed. In this first part of the tutorial theContinue Reading

2011-05-15

The first macro created in this section of the tutorial improves on the previously developed macro by correcting the up-down orientation of the shape, referencing the shape position to the coordinate of the first drawn point and closing the shape by repeating the coordinates of the first point at the end of the table. A last macro is then created whichContinue Reading

2011-05-14

Using autoshape freeforms is a very easy way to duplicate object outlines from pictures. It is convenient to create a freeform and once created, its vertices (points) can be edited with without difficulty. Aditional points can be inserted and others can be deleted. This is a tutorial about a series of macros which allow the extraction of freeform vertex coordiantes to a worksheetContinue Reading

2011-05-13

This tutorial will introduce the reader to creating simple drawings in Excel by using the “Freeform” auto shape. Later on, we will be able to convert this data in x-y-z vertex information for various models by using a macro. [sociallocker][/sociallocker] Drawing in Excel – part #1 – an introduction tocreating freeform type autoshapes – On this blog we will soon need toContinue Reading

2011-05-09

Reach out for your 3D goggles because this is a representation of the Cosmos through the eyes of a 5-year old. The model displays a few objects at various depths and move two of them back and forth on a chart to demonstrate the stereoscopic effect. Though very simplistic it is an excellent example of anaglyph stereoscopy in action showing youContinue Reading

2011-04-25

This is a linear system of equations solver in Excel. The size of the system is programmable by the user from 2 to 20 which means, depending on the setting selection, the model can instantly find the solution of linear systems starting from 2 equations and 2 unknowns up to 20 equations and 20 unknowns. It uses the following built-inContinue Reading

2011-04-24

This brief tutorial explains how to calculate the solution vector of a system of linear equations using the Excel spreadsheet function MINVERSE() which calculate the inverse of a matrix. [sociallocker][/sociallocker] Solving linear systems of equations in Excel – the easy way by George Lungu – This is a tutorial showing an easy and convenient method of solving moderate size systemsContinue Reading

2011-04-13

This is a brief tutorial showing how to calculate the determinant of a matrix and the inverse of a matrix using two special spreadsheet functions MDETERM() and MINVERSE(). [sociallocker][/sociallocker] MDETERM() & MINVERSE() – two important Excel spreadsheet functions for matrix manipulations by George Lungu – Using Excel built-in matrix operation functions might improve calculation efficiency but it definitely makes modelContinue Reading

2011-04-11

This is a tutorial introducing two important matrix manipulation spreadsheet functions in Excel: the matrix transposition function TRANSPOSE() and the matrix multiplication function MMULT(). These functions are a bit harder to use than the regular spreadsheet functions in the sense that the result is a matrix and a matrix cell range is treated by the program as a unity (you cannot change theContinue Reading

2011-03-03

This section explains how to create a compound sound effect from elementary sounds. In the first example (two macros), the sound is played in a loop which is a native internal loop within the “PlaySound” function (using the flag option: SND_LOOP = &H8). A second function (the “Beep” function) creates a tone generator with adjustable frequency and play time. The Beep functionContinue Reading

2011-03-02

This tutorial is an introduction to VBA sound playing macros in Excel. The sound effects can be used in various scientific and engineering models or in games. It first shows the general syntax of a sound playing macro and few sources of downloading free .wav sound files. The first demo macro plays a short sound a single time and theContinue Reading

2011-02-18

The macro in this tutorial creates a near exponential variable conversion to be used for very large dynamic range input data entry . If for instance, we have to adjust a parameter from 1 to 1 million we can either make a spin button which can go from 1 to 1 million in unity steps (which would take for ever), or implementContinue Reading

2011-02-16

Most of the models on this blog are designed for Excel 2003 or earlier versions. Sometimes however, Excel 2007 or 2010 are the only versions available even though they might be far slower when running these models. This presentation is an introduction to Excel 2007 and it was suggested to me by one of my readers. [sociallocker] [/sociallocker] Creating, Sizing,Continue Reading