You have not given much information about what you want to do, so I'm going to make a few guesses, and then make some suggestions.
- I gather that you have force sensors arranged either fixed-in-space on a stationary surface where a subject stands, or placed on something attached to the subject directly (so it is in a known position relative to the foot, rather than to the floor). In any case, the relationship of the sensors to each other is fixed.
- I assume that you can map the 10-20 (I'm guessing numbers here) sensors to a fixed set to integer coordinates. I'm specifying integer coordinates because I want to make a 3D graph where the X-Y plane are the (integer) coordinates of the sensors and the Z value is related to the force recorded by the sensor.
- I assume that you have a way of getting an array of 10-20 "force numbers" for your sensors, and that this comes in at some regular rate, say 10 samples/second (where by "sample" I mean a single reading from all of the sensors).
Let's say these assumptions are reasonable. Let's also say that it makes sense to map your sensor coordinates onto a 300 by 300 array, which could be the X-Y position of the sensor in millimeters. [The size of the array isn't too important, as long as (a) the actual dimensions are big enough to contain your array of sensors and (b) the number of points is "reasonable" given the precision with which you need to locate these points. Note that a 30 by 30 array, where each point represents a centimeter, might be more appropriate.]
So now you have 10-20 numbers from your sensors. Create an array of 300 by 300 (or 30 by 30) values, most of which are 0 (because there is no sensor there), and the 10-20 points representing your sensor locations have (positive) values corresponding to the recorded force. Now plot this array as an Intensity Graph, using an appropriate Color Map to render the different forces as different colors. Note that you'll get 10-20 single points lighting up on what should be a sea of black (if you mapped 0 to black). If you need something prettier, you could replace the single point with a Gaussian centered on the point with a standard deviation of a few points -- play with this to see how it looks.
Bob Schor
