Pick events for data interaction in Matplotlib - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to connect the pick event handler to the figure.

Matplotlib

fig.canvas.mpl_connect('[1]', on_pick)

Drag options to blanks, or click blank then click option'

Aresize_event

Bpick_event

Ckey_press_event

Dbutton_press_event

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'button_press_event' instead of 'pick_event'.

Confusing key press events with pick events.

The pick_event is the event triggered when a pickable artist is clicked.

2fill in blank

medium

Complete the code to make the scatter plot points pickable.

Matplotlib

scatter = ax.scatter(x, y, picker=[1])

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ATrue

BFalse

CNone

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Setting picker to False disables picking.

Using None does not enable picking.

Setting picker=True makes the scatter points respond to pick events.

3fill in blank

hard

Fix the error in the pick event handler to print the index of the picked point.

Matplotlib

def on_pick(event):
    ind = event.ind[[1]]
    print(f"Picked point index: {ind}")

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A-1

B1

C0

Dlen(event.ind)

Attempts:

3 left

💡 Hint

Common Mistakes

Using 1 causes index error if only one point is picked.

Using len(event.ind) is out of range.

The event.ind is a list of indices; use 0 to get the first picked point.

4fill in blank

hard

Fill both blanks to create a pick event handler that changes the color of the picked point to red.

Matplotlib

def on_pick(event):
    ind = event.ind[0]
    scatter._facecolors[ind] = [1]
    scatter.figure.canvas.[2]()

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A[1, 0, 0, 1]

B[0, 1, 0, 1]

Cdraw_idle

Dshow

Attempts:

3 left

💡 Hint

Common Mistakes

Using green color instead of red.

Calling show() instead of draw_idle() to refresh.

Set the facecolor to red using RGBA [1,0,0,1] and refresh the canvas with draw_idle().

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that maps point indices to their x-coordinates for points with x > 0.5.

Matplotlib

selected_points = [1]: x[[2]] for [1] in range(len(x)) if x[[2]] > 0.5}

Drag options to blanks, or click blank then click option'

Ai

Bx

Dj

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variables for keys and values causing errors.

Using 'x' as index variable instead of 'i'.

Use i as the index variable and key, and access x[i] for values and condition.