FStep | simple example project for KitKat 's step counter

Regarding xtics, you do the following:

Your main() function contains list1 = list(map(rayleightest,t,f)). This is how you get one answer per pair of values in t and f and got a bunch of values as a result. In other words the code computes rayleightest(t[0], f[0]), then rayleightest(t[1], f[1]), and so on.

When you use the code z = rayleightest(t, f) you pass 2 numpy arrays instead of 2 numbers. The result is a single value because the formula in rayleightest() contains np.sum() - you sum up all the values in arrays in a single value.

So the formula is the reason why you get single value for different input data. It is up to you to answer the question if this is expected behavior of the calculation process.

Now to the question why you get the same values in the list in the first case. Because for every pair of numbers you basically compute sin(x * y) ** 2 + cos(x * y) ** 2 which is always 1 so z in rayleightest equals to just 1 / n.

EDIT

Now when you have provided the original formula you try to implement with the code it became more clear what the problem actually is.

Modifications I've made:

(1) list1 = [rayleightest(t, val) for val in f]

(2) x = np.arange(fmin, fmax, fstep)

(3) plt.plot(x, list1, 'r-', label='data')

Result I get:

As far as I understand your question, it seems to me that you could just displace individual "profiles" on the x-axis. For example: