Hi guys, here is the first part of a tutorial describing the mathematical equations used in modeling a three-pendulum harmonograph (automatic drawing machine). It pertains to the second version of the model. This section refers only to the kinematic equations for the movement of three pendulums. A second section will be published later and it will describe the kinematic equations involved inContinue Reading
Hi! Here is an improved (faster and cleaner) version of the harmonograph. The worksheet has three different areas, the physical machine (a photo of the machine build out of wood by Karl Sims), the virtual machine (which is a 2D chart with a top view of a model showing the three pendulum ends, the drawing table, and the linkage mechanism which connects pendulum #1,Continue Reading
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 loveContinue Reading
Hi guys, here is the final part of tutorial about creating a digital clock in Excel. It is a good tutorial about general use of sprites in animation, especially the first half. Tell us your thoughts, George [sociallocker][/sociallocker] Building an Digital Clock in Excel – part #2 – a full digital clock model using the “digit” sprites by George LunguContinue Reading
Hello! Due to some incompatibility, I re-adjusted the old digital clock for the 2007 version of Excel. In Excel 2003 or earlier if you click on a chart point twice (with a certain delay between clicks) you can paste a picture and have the data point actually convert into that picture. In 2007 the same trick works but somehow the pictureContinue Reading
Hi guys, this is part #1 of a tutorial showing how to generate sprites used in a digital clock model. Sprites are typically simplified images (usually two-dimensional) which are used to replace complex but remote 3D-objects in an image. When an object is far away from the viewer a three-dimensional representation is not necessary since the eye cannot see all the details,Continue Reading
Hi there, this is a better version of Pong, in which you play with a virtual opponent. It does not have a score board yet and the opponent is theoretically unbeatable. I will be improving it further. Excel 2007 is quite slow on this one. In order to get maximum speed out of Excel 2007 make sure you zoom in as much asContinue Reading
Hi folks, this is a “practice box” for pong. The green button will “Start-Stop” the model and will also link the mouse to the bat (racket) for game control . The bat control is very smooth and quick and no mouse clicking is necessary. The red “Serve” button will shoot a new ball when you loose the old one (you don’t need to stopContinue Reading
Here is another example of sprite animation in Excel (Office 2007 will work fine, though a little bit slower). We’d love to hear from you. GeorgeContinue Reading
Ladies and Gentlemen, you will like this. Here is a harmonograph in MS Excel 2003 which models a real one build by Karl Sims. Watch the video first to know what to expect. I could have built it from the bare drawing equations but that would have been too easy and no fun at all so I tried to model theContinue Reading
Hi folks, as a continuation to the previous tutorial here is a 3-body planetary model where the solution to the equations is contained in a static form, as a lookup table (I previously called it a “pure spreadsheet solution”). The model is static in the sense that after any parameter is changed, the solution data remains unchanged in a table until a new parameter is updated by theContinue Reading
Here is a tutorial explaining how to model a two dimensional 2-body planetary system in Excel. It uses the Euler method of integration. The tutorial starts with explaining the simple Newtonian laws acting on the two planets. There are essentially just two forces acting on each body at any time: the inertia and the gravitational attraction. During each small time step,Continue Reading
Hi guys, here is an animation I made yesterday by downloading 120 pictures of the Earth taken 12 minutes apart by satelites above the equator at 30 degrees longitude west on 10/01/2010. The pictures are 500 x 500 pixels and they are pasted as a background of a chart by a slimmed down VBA macro. You can change the speed ofContinue Reading
Here is a speedometer in Excel 2003. It’s an old file and the charting wasn’t done in the most economic fashion. I used too many series while I could have consolidated a lot of the dial curves. It is still a good example of animation and displaying custom numbers on a chart. There are two VBA macros involved, one for changingContinue Reading
Hi guys, here is a dynamic digital clock model in Excel I made today. The display looks very realistic. I studied for this all the clocks in the house including the stove, microwave oven and washing machine clocks, plus some pictures on Google. It will display your local computer time. It uses “sprites” as a method of creating the digits. IContinue Reading
Hi there, this is a tutorial explaining the construction of a very basic Lissajous emulator in Excel. It’s supposed to be very easy to understand at the high school level. Good luck, George [sociallocker][/sociallocker] A Lissajous emulator in Excel by George Lungu Introduction: Jules A. Lissajous was a French mathematician from the 19th century – He wanted to visualizeContinue Reading