def binary_widget(nbits=5):
nbits = max(min(10, nbits), 2) # Keep nbits between 2 and 10
output = _pre()
bits = ['0' for i in range(nbits)]
button_list = [widgets.ToggleButton(description=str(2**i),
layout=widgets.Layout(width='3em',height='3em'))
for i in reversed(range(nbits))]
hbox = widgets.HBox(button_list)
label1 = widgets.Label(value="Toggle the bits below to change the binary number.")
label2 = widgets.Label(value="Think of a number between 0 and %i and try to write it down in binary." % ((2**nbits)-1))
vbox = widgets.VBox([label1,label2,hbox])
def on_btn_click(b):
for b in range(nbits):
if button_list[b].value:
bits[b] = '1'
else:
bits[b] = '0'
string = "".join(bits)
output.value = "Binary" + " "*(nbits//2) + " Decimal\n " + string + " = " + str(int(string,2))
for button in button_list: button.observe(on_btn_click)
# Add output before button press
string = "".join(bits)
output.value = "Binary" + " "*(nbits//2) + " Decimal\n " + string + " = " + str(int(string,2))
display(vbox)
display(output.widget)
def state_vector_exercise(target):
output = _pre()
button = widgets.Button(description="Check", layout=widgets.Layout(width='5em'))
text_input = widgets.Text(value='[1, 0]',
placeholder='Type something',
width='50px',
disabled=False)
label = widgets.Label(value="State Vector:")
def on_button_click(b):
try:
state_vector = eval(text_input.value)
c1, c2 = state_vector[0], state_vector[1]
except Exception as e:
output.value = str(e).split("(")[0]
return
squared_magnitude = abs(c1)**2 + abs(c2)**2
p = abs(c1)**2
if not (squared_magnitude < 1.01 and squared_magnitude > .99): # Close Enough
output.value = "Magnitude is not equal to 1"
return
elif p > target*0.99 and p < target*1.01:
output.value = "Correct!"
else:
output.value = "The absolute value of " + str(c1) + ", squared is not equal to " + str(target)
hbox = widgets.HBox([text_input, button])
vbox = widgets.VBox([label, hbox])
button.on_click(on_button_click)
display(vbox)
display(output.widget)
def bloch_calc():
output = _pre()
button = widgets.Button(description="Plot",
layout=widgets.Layout(width='4em'))
theta_input = widgets.Text(label='$\\theta$',
placeholder='Theta',
disabled=False)
phi_input = widgets.Text(label='$\phi$', placeholder='Phi', disabled=False)
label = widgets.Label(
value="Define a qubit state using $\\theta$ and $\phi$:")
image = _img(value=plot_bloch_vector([0, 0, 1]))
def on_button_click(b):
from math import pi, sqrt
try:
theta = numexpr.evaluate(theta_input.value)
phi = numexpr.evaluate(phi_input.value)
except Exception as e:
output.value = "Error: " + str(e)
return
x = sin(theta) * cos(phi)
y = sin(theta) * sin(phi)
z = cos(theta)
# Remove horrible almost-zero results
if abs(x) < 0.0001:
x = 0
if abs(y) < 0.0001:
y = 0
if abs(z) < 0.0001:
z = 0
output.value = "x = r * sin(" + theta_input.value + ") * cos(" + phi_input.value + ")\n"
output.value += "y = r * sin(" + theta_input.value + ") * sin(" + phi_input.value + ")\n"
output.value += "z = r * cos(" + theta_input.value + ")\n\n"
output.value += "Cartesian Bloch Vector = [" + str(x) + ", " + str(
y) + ", " + str(z) + "]"
image.value = plot_bloch_vector([x, y, z])
hbox = widgets.HBox([phi_input, button])
vbox = widgets.VBox([label, theta_input, hbox])
button.on_click(on_button_click)
display(vbox)
display(output.widget)
display(image.widget)