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 you… Read More... "Cosmos Naive – a very basic demo of anaglyph stereoscopy with sprites in Excel"
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-in… Read More... "A Solver for Systems of Linear Equations in Excel"
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 systems… Read More... "The Easy Way of Solving Systems of Linear Equations in Excel – using the INVERSE() spreadsheet function"
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 model… Read More... "MDETERM() & MINVERSE() – two important Excel spreadsheet functions for matrix manipulations"
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 the… Read More... "TRANSPOSE() & MMULT() – two important Excel spreadsheet functions for matrix manipulations"
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 function… Read More... "Playing Sounds in Excel Using VBA – part #2"
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 the… Read More... "Playing Sounds in Excel Using VBA – part #1"
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 implement… Read More... "Near-Exponential VBA Conversion"
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,… Read More... "Creating, Sizing, Translating and Rotating 2D Shapes in Excel 2007"
In certain models we need to be able to change the scale of the chart axes function of the result of a simulation. Excel charts do have auto-scaling as a default option but sometimes the scaling values we get are not what we need. Another reason against using auto-scaling is that during the time the model runs, the scale self-adjusts and… Read More... "Easy Zoom – Chart Axis Scaling Using VBA"
Hello everyone, this is a tutorial in which a virtual Excel joystick controlled by mouse movements on a scatter chart has been demonstrated . While in operation, a macro updates the coordinates of the pointer in two spreadsheet cells. The two coordinates are then incorporated in formulas which limit the range of motion of the joystick. Just like a real… Read More... "A Virtual Joystick – How Can You Make That ? – tutorial"
Hi Folks, there are many available built-in spreadsheet functions in Excel. Ocasionaly one might need to write a special custom function. This second short tutorial is an introduction to that. Creating a “Time Stamp” function is presented as a first example after which a concatenation function between a custom formatted date and a string (text) is introduced. This last function came about from… Read More... "Writing Excel User Defined Functions in VBA – part #2 – time stamping, concatenating date and text while maintaining the date format"
There are many available built-in spreadsheet functions in Excel. Occasionally one might need a very special custom function. This short tutorial is an introduction about how to write a user defined function which calculate the distance between two points in a Cartesian plane. The topic will be continued and custom functions will occasionally be used in future models. We’d love… Read More... "Writing Excel User Defined Functions in VBA – part #1 – the distance function"
Hi everybody, Today we’ll talk about dynamic macros very useful in engineering modeling, scientific modeling, games etc. Dynamic macros are created using two different type of loops: “For” and “Do”. – Two different but equivalent conditional “Do” loops are explored. – It is shown that macros can be assigned to drawing shapes, pictures, graph, etc. – A highly valuable Run/Pause macro… Read More... "Dynamic Macros #1"