【python海洋专题九】Cartopy画地形等深线图
水深图基础差不多了，可以换成温度、盐度等
本期加上等深线
本期内容
1：地形等深线
cf = ax.contour(lon, lat, ele[:, :], levels=np.linspace(-9000,-100,10),colors='gray', linestyles='-',linewidths=0.25, transform=ccrs.PlateCarree())2：改变颜色
colors='gray'3：改变粗细
linewidths=1，数字越大线条越粗。4：特定等值线
levels=[-9000, -8000, -5000, -3000, -1000, -300]；想画哪条，填写对应数字。5：特定线条特定颜色和粗细
cf = ax.contour(lon, lat, ele[:, :], levels=[-8000,-6000,-4000,-2000,-200],colors='k', linestyles='-',linewidths=0.3, transform=ccrs.PlateCarree())cf = ax.contour(lon, lat, ele[:, :], levels=[-3000],colors='r', linestyles='-',linewidths=0.5, transform=ccrs.PlateCarree())6：线条样式
linestyles='-.
图片 图片 图片 图片 图片
图片 7：显示数字
ax.clabel(cf,inline=True,fmt=‘%.f’,fontsize=3.5) 出现错误：不会了！
‘codes’ must be a 1D list or array with the same length of ‘vertices’. Your vertices have shape (2, 2) but your codes have shape (1,)
8：填充加上等值线
参考文献及其在本文中的作用
Python气象绘图笔记（五）——等高线 - 知乎 (zhihu.com)
【python海洋专题一】查看数据nc文件的属性并输出属性到txt文件
【python海洋专题二】读取水深nc文件并水深地形图 【python海洋专题三】图像修饰之画布和坐标轴
【Python海洋专题四】之水深地图图像修饰
【Python海洋专题五】之水深地形图海岸填充
【Python海洋专题六】之Cartopy画地形水深图
【python海洋专题】测试数据
【Python海洋专题七】Cartopy画地形水深图的陆地填充
【python海洋专题八】Cartopy画地形水深图的contourf填充间隔数调整
# -*- coding: utf-8 -*-# %%# Importing related function packagesimport matplotlib.pyplot as pltimport cartopy.crs as ccrsimport cartopy.feature as featureimport numpy as npimport matplotlib.ticker as tickerfrom cartopy import mplfrom cartopy.mpl.ticker import LongitudeFormatter, LatitudeFormatterfrom cartopy.mpl.gridliner import LONGITUDE_FORMATTER, LATITUDE_FORMATTERfrom matplotlib.font_manager import FontPropertiesfrom netCDF4 import Datasetfrom palettable.cmocean.diverging import Delta_4from palettable.colorbrewer.sequential import GnBu_9from palettable.colorbrewer.sequential import Blues_9from palettable.scientific.diverging import Roma_20from pylab import *def reverse_colourmap(cmap, name='my_cmap_r'):reverse = []k = []for key in cmap._segmentdata:k.append(key)channel = cmap._segmentdata[key]data = []for t in channel:data.append((1 - t[0], t[2], t[1]))reverse.append(sorted(data))LinearL = dict(zip(k, reverse))my_cmap_r = mpl.colors.LinearSegmentedColormap(name, LinearL)return my_cmap_rcmap = Blues_9.mpl_colormapcmap_r = reverse_colourmap(cmap)cmap1 = GnBu_9.mpl_colormapcmap_r1 = reverse_colourmap(cmap1)cmap2 = Roma_20.mpl_colormapcmap_r2 = reverse_colourmap(cmap2)# read dataa = Dataset('D:\pycharm_work\data\scs_etopo.nc')print(a)lon = a.variables['lon'][:]lat = a.variables['lat'][:]ele = a.variables['elevation'][:]# 图三# 设置地图全局属性scale = '50m'plt.rcParams['font.sans-serif'] = ['Times New Roman'] # 设置整体的字体为Times New Romanfig = plt.figure(dpi=300, figsize=(3, 2), facecolor='w', edgecolor='blue')#设置一个画板，将其返还给figax = fig.add_axes([0.05, 0.08, 0.92, 0.8], projection=ccrs.PlateCarree(central_longitude=180))ax.set_extent([105, 125, 0, 25], crs=ccrs.PlateCarree())# 设置显示范围land = feature.NaturalEarthFeature('physical', 'land', scale, edgecolor='face',facecolor=feature.COLORS['land'])ax.add_feature(land, facecolor='0.6')ax.add_feature(feature.COASTLINE.with_scale('50m'), lw=0.3)#添加海岸线：关键字lw设置线宽;linestyle设置线型cs = ax.contourf(lon, lat, ele[:, :], levels=np.arange(-9000,0,20),extend='both',cmap=cmap_r1, transform=ccrs.PlateCarree())# ------colorbar设置cb = plt.colorbar(cs, ax=ax, extend='both', orientation='vertical',ticks=np.linspace(-9000, 0, 10))cb.set_label('depth', fontsize=4, color='k')#设置colorbar的标签字体及其大小cb.ax.tick_params(labelsize=4, direction='in') #设置colorbar刻度字体大小。cf = ax.contour(lon, lat, ele[:, :], levels=[-5000,-2000,-500,-300,-100,-50,-10],colors='gray', linestyles='-',linewidths=0.2,transform=ccrs.PlateCarree())#ax.clabel(cf, inline=True, fontsize=8, colors='red', fmt='%1.0f',manual=False)#ax.clabel(cf,inline=True,fmt='%.f',fontsize=3.5)# 添加标题ax.set_title('Etopo', fontsize=4)# 利用Formatter格式化刻度标签ax.set_xticks(np.arange(107, 125, 4), crs=ccrs.PlateCarree())#添加经纬度ax.set_xticklabels(np.arange(107, 125, 4), fontsize=4)ax.set_yticks(np.arange(0, 25, 2), crs=ccrs.PlateCarree())ax.set_yticklabels(np.arange(0, 25, 2), fontsize=4)ax.xaxis.set_major_formatter(LongitudeFormatter())ax.yaxis.set_major_formatter(LatitudeFormatter())ax.tick_params(color='k', direction='in')#更改刻度指向为朝内，颜色设置为蓝色gl = ax.gridlines(crs=ccrs.PlateCarree(), draw_labels=False, xlocs=np.arange(107, 125, 4), ylocs=np.arange(0, 25, 2),linewidth=0.25, linestyle='--', color='k', alpha=0.8)#添加网格线gl.top_labels, gl.bottom_labels, gl.right_labels, gl.left_labels = False, False, False, Falseplt.savefig('scs_elevation1.jpg', dpi=600, bbox_inches='tight', pad_inches=0.1) # 输出地图，并设置边框空白紧密plt.show()
