In the last section, we covered the use of a slider. The most important attribute of a slider is its value, val. This is communicated to the call-back function.
Other attributes are the limits of the value given by the slider, valmin, and valmax, and a stepping functionality, valstep, to make the change to the value discrete. A formatting attribute, valfmt, allows us to specify how valmin and valmax are displayed.
In the next example, we modify the slider definition from above and provide it with these more specific attributes:
sld = Slider(sld_ax, label='$\omega$ [Hz]', valmin=1., valmax=5.,
valinit=1.5, valfmt='%1.1f', valstep=0.1)
The formatting argument, %1.1f, in this example says that the value should be displayed as a floating-point number, with one digit to the left of the decimal point and one digit to the right of it.