Python程序设计基础（第3版）-习题及答案 【ch09】图形绘制与数据可视化

第九章图形绘制与数据可视化1.答：importnumpyasnpimportmatplotlib.pyplotasplt#创建400x400像素的画布fig,ax=plt.subplots(figsize=(4,4))#设置坐标轴放大倍数x_scale=80y_scale=35#绘制坐标轴ax.axhline(y=0,color='red',linestyle='-',linewidth=1)ax.axvline(x=0,color='red',linestyle='-',linewidth=1)#设置坐标轴范围ax.set_xlim(-x_scale*1.7,x_scale*1.7)ax.set_ylim(-y_scale,y_scale)#在区间[-1.7,1.7]上生成步长为0.02的x值x_values=np.arange(-1.7,1.7,0.02)#定义函数f(x)deff(x):return3*x-3*x+4*np.sin(x)#绘制放射线ax.plot(x_values,f(x_values),color='black',label='QuadrantI')ax.plot(x_values,-f(x_values),color='red',label='QuadrantII')ax.plot(x_values,-f(x_values)+4,color='green',label='QuadrantIV')ax.plot(x_values,f(x_values)-4,color='blue',label='QuadrantIII')#添加图例ax.legend()#显示图形plt.show()2.答：importnumpyasnpimportmatplotlib.pyplotasplt#创建400x400像素的画布fig,ax=plt.subplots(figsize=(4,4))#设置坐标轴放大倍数x_scale=80y_scale=35#绘制坐标轴ax.axhline(y=0,color='red',linestyle='-',linewidth=1)ax.axvline(x=0,color='red',linestyle='-',linewidth=1)#设置坐标轴范围ax.set_xlim(-x_scale*1.7,x_scale*1.7)ax.set_ylim(-y_scale,y_scale)#在区间[-1.7,1.7]上生成步长为0.02的x值x_values=np.arange(-1.7,1.7,0.02)#定义函数f(x)deff(x):return3*x-3*x+4*np.sin(x)#绘制函数图形ax.plot(x_values,f(x_values),color='red')ax.plot(x_values,-f(x_values)+20,color='blue')#显示图形plt.show()3.答：importnumpyasnpimportmatplotlib.pyplotasplt#创建600x600像素的画布fig,ax=plt.subplots(figsize=(6,6))#绘制坐标轴ax.axhline(y=0,color='red',linestyle='-',linewidth=1)ax.axvline(x=0,color='red',linestyle='-',linewidth=1)#参数aa=80#定义函数x(t)和y(t)defx(t):returna*(2*np.sin(t)-np.sin(2*t))defy(t):returna*(2*np.cos(t)-np.cos(2*t))#在区间[-2*pi,2*pi]上生成步长为0.01的t值t_values=np.arange(-2*np.pi,2*np.pi,0.01)#绘制函数图形ax.plot(x(t_values),y(t_values),color='blue')#设置坐标轴范围ax.set_xlim(-a*3,a*3)ax.set_ylim(-a*3,a*3)#显示图形plt.show()4.答：importnumpyasnpimportmatplotlib.pyplotasplt#创建600x600像素的画布fig,ax=plt.subplots(figsize=(6,6))#设置画布半宽和半高w=300h=300#绘制坐标轴ax.axhline(y=0,color='red',linestyle='-',linewidth=1)ax.axvline(x=0,color='red',linestyle='-',linewidth=1)#设置坐标轴范围ax.set_xlim(-w,w)ax.set_ylim(-h,h)#在区间[0,2π]上生成步长为0.01的t值t_values=np.arange(0,2*np.pi,0.01)#定义x和y的计算公式x=(w/4)*np.cos(2*t_values)*np.sin(t_values)y=(h/4)*np.cos(2*t_values)*np.cos(t_values)#绘制花形状ax.plot(x,y-10,color='red',label='QuadrantII')ax.plot(x,-y+10,color='green',label='QuadrantIIIandIV')#添加图例ax.legend()#显示图形plt.show()5.答：importnumpyasnpimportmatplotlib.pyplotasplt#创建600x600像素的画布fig,ax=plt.subplots(figsize=(6,6))#设置画布半宽和半高w=300h=300#绘制坐标轴ax.axhline(y=0,color='red',linestyle='-',linewidth=1)ax.axvline(x=0,color='red',linestyle='-',linewidth=1)#设置坐标轴范围ax.set_xlim(-w,w)ax.set_ylim(-h,h)#在区间[0,25]上生成步长为0.01的t值t_values=np.arange(0,25,0.01)#定义x和y的计算公式x=w/32*(