python - 绘图 : Plot a curve with ticks on one side

Question

我可以使用 matplotlib.pyplot 中的 plot() 函数来绘制一侧有刻度的曲线吗？:

Answer 1

升级基于答案here我可以扩展示例:

def f(x): return x,  x * np.exp(-x*x)

def get_parameters(x,y):
    xp = 0.5*(x[1:nx] + x[0:nx-1])           # the points between
    yp = 0.5*(y[1:nx] + y[0:nx-1])
    dy = np.diff(y); dx = np.diff(x)         # the gradient
    nn = 40*np.sqrt(dx*dx + dy*dy)           # nn=norm; 40 = empirical hack for the normal shift
    dx = dx/nn;  dy = dy/nn                  # the components of the normals
    alpha = 180*np.arctan(dy/dx)/np.pi       # the slope angel to the normal
    return xp,yp,dx,dy,alpha

nx = 20;
ip = np.linspace(0,1,nx)
xr,yr = f(3*ip-0.5)                           # red front line
xb,yb = f(3*ip-0.5); yb = 0.7*yb -0.3         # blue front line

xpb, ypb, dx, dy, alphaB = get_parameters(xb,yb) # red points between
xpr, ypr,  _,  _, alphaR = get_parameters(xr,yr) # blue points between

plt.style.use('fast')  
fig, ax0 = plt.subplots(figsize=(20,20))
plt.plot(xr,yr, c='r', lw=5, label='warm front')
plt.plot(xb,yb, c='b', lw=5, label='cold front')

for j in range(nx-1):
    #--- set the blue markers ---
    marker_size_B = 900
    plt.scatter(xpb[j]-dy[j], ypb[j]+dx[j],
                s=marker_size_B, c='b', marker=(3, 0, alphaB[j]) )    

    #--- set the red markers ---
    marker_size_R=0.05
    halfR = mpl.patches.Wedge((xpr[j], ypr[j]), marker_size_R, theta1=0+alphaB[j], theta2=180+alphaB[j], color='r')
    ax0.add_artist(halfR)
plt.legend(prop={'size': 20})
ax0.set_aspect('equal'); plt.grid(); plt.margins(0.1);plt.show()

标记的密度可以用 marker_every 控制.