Recent content by swied

Attached is a time series graph of the x,y,z accelerations. It looks like a classical damped pendulum. The noise at the beginning and end are from my hand starting and stopping the swinging iPhone. Edit: I forgot to mention that the acceleration values are measured with respect to gravity...

Here is another data set that is a little more interesting than what I posted previously. I attached a string to the belt clip on the case of my iPhone, and let it swing back and forth from a fixed point on my desk. The string was about 18 inches long. I tried several sampling rates, and...

Hmm. I guess you can't upload .csv files. I changed the extension to .txt, and tried again. Hopefully it will work this time.

Here is a sample file of raw accelerometer data measured at 60 Hz. To keep it simple, I put the phone flat on a table, I hit the start sampling button, took my hand away for a couple seconds, grabbed the phone and slid it across the table, let go of the unit for a second, grabbed it again, and...

The data is on my computer at home. I'll post it later tonight.

I wanted to use the raw data from my iPhone accelerometer to track displacement. I downloaded an app called Accelerometer Data Pro. It is pretty fun. You slide a bar to start sampling, walk around the room, and then slide the same bar to stop sampling. The time series results can then be...

Thanks to everyone for the great help. You nailed it! I think I have enough information to make my template now. I'll post it here when I'm all finished with the design. It is going to be a wooden surfboard. The template is going to be of the boards cross section. Redbelly98: Thanks...

I already explored using an ellipse. Yes, it is much easier to solve, but it just doesn't look right. The ellipse is too arcing out towards point b. I need to find a curve that is fairly flat and then curves in quickly at the edge towards point a. I'm heading out of town in a few minutes...

Here are the base equations that I am starting from... y' = a0 + a1 x' + a2 x'^2 The rotation would be defined by the following two equations... y' = -x sin(theta) + y cos(theta) x' = x cos(theta) + y sin(theta) Given point a at (0,0), and point b at (10, 3). I'm tying to solve...

Here is a picture of what I am trying to represent. http://www.swied.com/pics/parabola.png" This isn't a homework problem. I'm actually trying to design a template for a wood working project. Of all the conic sections I think that the parabola is the most appropriate.

This question seems easy enough, but I'm having a hard time getting my mind around it. I want to find the solution to a second order polynomial (parabola) defined by the following criteria... 1) It passes through points a and b 2) At point a the slope of the curve is zero (horizontal) 3)...