"Python" Scientific Computing Special _ Scientific Drawing library Matplotlib Learning

Thought: All things are objects

Homework

First question:

Import NumPy as Npimport matplotlib.pyplot as Pltx = [1, 2, 3, 1]y = [1, 3, 0, 1]def plot_picture (x, y):    plt.plot (x, y , color= ' R ', linewidth= ' 2 ', linestyle= '--', marker= ' D ', label= ' one ')    plt.xticks (list (range ( -5,5,1)))    Plt.yticks (list (range ( -5,5,1)))    Plt.grid(True)    def rotate (x0, y0, point=[0, 0], ANGLE=NP.PI/2):    rx = []    ry = []    for I, POS in enumerate (Zip (x0,y0)):        rx.append ((x0[i]-point[0)) * Np.cos (angle)-(y0[i]-point[1]) *np.sin (angle) + point[0])        ry.append ((y0[i]-point[1)) *np.cos (angle) + (x0[i]- Point[0]) *np.sin (angle) + point[1])    return rx, Ryprint (rotate ([3,1],[0,1],angle=-np.pi/2)) plot_picture (x, y) Plot_picture (rotate (x, y, ANGLE=-NP.PI/2) [0], rotate (x, y, ANGLE=-NP.PI/2) [1])

The second question:

% matplotlib inlineimport NumPy as Npimport matplotlib.pyplot as Pltfig = Plt.figure () fig.add_subplot (321) fig.add_ Subplot (322) Fig.add_subplot (312) fig.add_subplot (325) Fig.add_subplot (326) fig.subplots_adjust (hspace=0.3)

Question three:

def rotate (x0, y0, point=[0, 0], ANGLE=NP.PI/2):    rx = []    ry = []    for I, POS in enumerate (Zip (x0,y0)):        rx.a Ppend ((x0[i]-point[0]) *np.cos (angle)-(y0[i]-point[1]) *np.sin (angle) + point[0])        ry.append ((y0[i]-point[1)) * Np.cos (angle) + (x0[i]-point[0]) *np.sin (angle) + point[1])    return rx, Rydef draw_flower (step=4, start_point=[2,0]) :    step = 2**step    start_x = [start_point[0]]    start_y = [Start_point[1]]    x = []    y = []    b_x = []
   b_y = []    for I in Range (step):        angle = (STEP/4) *2*np.pi/(step-1)        start_x, start_y = Rotate (start_x, STA Rt_y, Angle=angle)        x + = start_x        y + = start_y        if I! = 0:            b_x.append ((x[-2]+start_x)/2)            b_ Y.append ((y[-2]+start_y)/2)    plt.plot (x, Y, ' R ')    Plt.plot (b_x, b_y, ' B. ') Plt.axis (' equal ')    Plt.grid ( True) Draw_flower (6)

Required chrysanthemum diagram, hole a bit large, adjust angle can be resized,

The third question needs a little analytic geometry computation, the difficulty is not big, mainly is the recollection geometry knowledge to compare the pain, obviously just has tested, eh.

"Python" Scientific Computing Special _ Scientific Drawing library Matplotlib Learning