for the two cases. The first case is the motor ticks left and right are the same. In that case the robot just drives straight and if not the robot drives along a curved segment and you'll have to implement that case too. And these are the formulas we just discussed.

And I prepared a main function for you. There's the constant we just discussed, the ticks two millimeter conversion factor. Another constant is the width of the track in millimeters and the main function does all the opening of the file and the processing for the motor ticks. So here it opens the log file, it reads in the motor ticks,

then it starts at a given pose. So since I do not know the pose I just say it is at x zero y zero and with a heading of zero. And then I start to construct the list of the filtered positions. For all ticks in the motor ticks I just call this filter step function,

the one up here, which you'll have to implement. The filter step function takes the pose, takes ticks and computes the new pose. And then the new pose is just appended to this list. Then in the end I do two things. I print out all the positions and orientations and I also in addition do a plot. So now let's have a look at what the program does after you

implemented the filter step function. So I'll just run it and this is what happens. The program prints a long list of x y heading values. So if I scroll back, these are the first values. At the start of the experiment the robot stands still. So it is at zero zero with heading

zero. And at the beginning the motors are not turning. And for the first one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen. For the first thirteen time steps the robot stands still and then starts to accelerate and it goes straight.

Since the heading is along the x axis it goes into x direction and it accelerates. And then as you remember with the third value here the left and right ticks are a little bit different. So it starts to turn a little bit that the heading here switches to a value of something like

two pi. So when you implement this make sure that you have those thirteen zeros here and then the same values as you can see here. But the program does not only output those values it also draws a figure. So here's the figure it draws and you can see the robot starts at zero zero with heading along the x axis the theta equals zero. And then it moves and does a left

turn. And so you see for the first time you see the trajectory that the robot is moving in the arena. So now try to implement this. Have a look at the graphics and make sure that you get the correct values as they are shown here.