Python cartopy - 手动更改颜色条标签

问题描述

我有一个 netcdf 文件 ('test.nc')。 netcdf文件的变量如下：

variables(dimensions): float64 lon(lon),float64 lat(lat),int32 crs(),int16 Band1(lat,lon)

我对“Band1”变量感兴趣。 使用 cartopy，我可以使用以下代码绘制数据：

import numpy as np
import pandas as pd
import gzip
from netCDF4 import Dataset,num2date
import time
import matplotlib.pyplot as plt
import os 
import matplotlib as mplt
#mplt.use('Agg')
import cartopy.crs as ccrs
import cartopy.feature as cfea
import matplotlib.pyplot as plt
from mpl_toolkits.axes_grid1 import make_axes_locatable

projection=ccrs.PlateCarree()
bBox=[-180,180,-60,85];creg='glob'
mplt.rc('xtick',labelsize=9) 
mplt.rc('ytick',labelsize=9)

nc = Dataset('test.nc','r')
lat = nc.variables['lat'][:]
lon = nc.variables['lon'][:]
kopi= (nc.variables['Band1'][:,:])
nc.close()

fig=plt.figure(figsize=(11,5))
ax=fig.add_subplot(1,1,projection=projection)
ax.set_extent(bBox,projection)
ax.add_feature(cfea.COASTLINE,lw=.5)
ax.add_feature(cfea.RIVERS,lw=.5)
ax.add_feature(cfea.BORDERS,linewidth=0.6,edgecolor='dimgray')
ax.background_patch.set_facecolor('.9')
levels=[1,4,8,11,14,17,21,25,29]
cmap=plt.cm.BrBG
norm=mplt.colors.Boundarynorm(levels,cmap.N)
ddlalo=.25
pc=ax.contourf(lon,lat,kopi,levels=levels,transform=projection,cmap=cmap,norm=norm,extend='both')
divider = make_axes_locatable(ax)
ax_cb = divider.new_horizontal(size="3%",pad=0.1,axes_class=plt.Axes)
fig.colorbar(pc,extend='both',cax=ax_cb)
fig.add_axes(ax_cb)
fig.colorbar(pc,cax=ax_cb)
ttitle='Jony'
ax.set_title(ttitle,loc='left',fontsize=9)
plt.show()

在图的右侧，我有值从 1 到 29 的颜色条方案。是否可以手动更改这些值，以便将 1 写成“Class1”而不是 4 “Class4”等其他课程？

解决方法

它应该与任何其他颜色条完全相似... 例如像这样：

import matplotlib.pyplot as plt

f,ax = plt.subplots()
im = ax.imshow([[1,2,3],[1,3]])

cb = plt.colorbar(im)
cb.set_ticks([1,3])
cb.set_ticklabels(['first label','second label','third label'])