色标 - 接近但不够接近 [英] Color scale - close but not close enough

问题描述

我正在尝试制作一个使用与气象局相同色阶的图，以便我可以轻松地将我的图与他们的图进行比较.他们的一个例子是在这里

I'm trying to produce a plot which uses the same colorscale as the Met Office, so I can easily compare my plots to theirs. An example of theirs is at Here

我目前最接近的努力在这里:这里

My current closest effort is here: Here

我很欣赏我的代码很乱 - 我找不到一种方法来为高于某个阈值的值设置颜色(否则它会变成白色)，因此循环.

I appreciate my code is messy - I couldn't find a way to set a color for values above a certain threshold (otherwise it goes white),hence the loop.

我想上传 NetCDF 文件，但我没有足够高的代表来执行此操作.

I would upload the NetCDF File but I haven't got a high enough rep to do this.

非常感谢您的帮助.

我的绘图代码如下所示；

My code for plotting is shown below;

from Scientific.IO.NetCDF import NetCDFFile                     
from mpl_toolkits.basemap import Basemap                     
from matplotlib import pyplot as plt                      
import numpy as np


myfile = NetCDFFile('ERA_Dec_89-94.nc', 'r')   
Lat = NetCDFFile('/home/james/Documents/Lat_Lon_NC_Files/latitudes_d02.nc','r')
Long = NetCDFFile('/home/james/Documents/Lat_Lon_NC_Files/longitudes_d02.nc','r')


XLAT = Lat.variables['XLAT'][:]     
XLONG = Long.variables['XLONG'][:]      
ERA_Data = myfile.variables['Monthlyrain'][:]

plot = np.zeros([1000,1730])

plot[:,:] = np.average(ERA_Data[:,:,:],axis=0)

m = Basemap(projection='merc',resolution='f',llcrnrlat=49,llcrnrlon=-11,urcrnrlat=61,urcrnrlon=3)
m.drawparallels(np.arange(-90., 91., 5.), labels=[1,0,0,0], fontsize=11)
m.drawmeridians(np.arange(-180., 181., 5.), labels=[0,0,0,1], fontsize=11)
m.drawcoastlines()


X, Y = m(XLONG, XLAT)

for i in range(0,1729):
    for j in range(0,999):
         if plot[j,i] >250:
             plot[j,i] = 250.001
         if plot[j,i] < 40:
             plot[j,i] = 40

scale = [40,40.001,60,80,100,125,150,200,250, 250.001]
cs = m.contourf(X,Y,plot,scale, cmap='PuOr')
cbar = m.colorbar(cs, ticks=  [40.0005,50,70,90,112.5,137.5,175,225,250.0005])
cbar.set_ticklabels(['<40','40-60', '60-80', '80-100', '100-125', '125-150', '150-200', '200-250', '>250'])

plt.title('Some Title')
cbar.set_label('Monthly average rainfall (mm)')

print "Finished"

plt.show()

推荐答案

第一部分(正确设置颜色)已经回答.为了将值限制在某个范围内，您有多种选择.

The first part (getting the colors right) was already answered. In order to restrict the values to a certain range you have several options.

• 使用 cmap.set_over 和 cmap.set_under 设置越界颜色，如这里

• Use cmap.set_over and cmap.set_under to set out-of-bounds colors, as described here

使用np.clip 而不是将值限制在特定范围内的循环:

use np.clip instead of the loop to restrict the values to a certian range:

plot = np.clip(plot, 40, 250)

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