Question

经过几天试图解决这个问题，我想我会寻求帮助......

我有3个列表，lon，lat和pop的长度相同。使用lon [1]，lat [1]对应pop [1]。我想要做的是，在将它们绘制出来之后，将它们悬停在地图上＆＃39;然后（最终绘制每个点的人口时间序列）但是现在，我只想知道相应的人口价值是多少......

我一直在使用下面这个，但我不知道如何

a）使它到最近的纬度，lon点，因为它目前产生一个可能的选项列表

b）随着图放大然后点击，因为点击放大按钮似乎停止记录任何其他点...

#Import modules

import netCDF4 as nc4
from netCDF4 import Dataset
import matplotlib.pyplot as plt
import numpy as np
from mpl_toolkits.basemap import Basemap
from matplotlib import cm as cm
from matplotlib import mlab as ml
import matplotlib as mpl
from matplotlib.pyplot import figure, show

def extractdata(nc_filename,column_data):
    dataset=Dataset(nc_filename)    #Reads the data into a column format 
    output= dataset.variables[column_data][:]
    dataset.close()

    return(output)

#Start of program

inputfile='reference_pop.nc'
dataset = Dataset(inputfile)
print(dataset.variables.keys())

time=extractdata(inputfile,'time')
lon=extractdata(inputfile,'lon')
lat=extractdata(inputfile,'lat')
pop=extractdata(inputfile,'pop')



index=np.arange(len(lat))

#Reverse the time order (So that 0 is 120,000 years ago aka from past to present
time=time[::-1]
#Reverse population order 
pop=pop[::-1]   #Population is a 2d matrix, of dimensions pop and len(lon/lat)



def onpick3(event):
    ind = event.ind
    #print 'onpick3 scatter:', ind, npy.take(lon, ind), npy.take(lat, ind)
    print 'ind', ind    #Example output: [2513 2673 2843 3022 3023 3024 3025 3203]
    print 'npy.take(lon, ind)',npy.take(lon, ind)  #Example output [ 21398764.  21459962.  21520490.  21391092.  21454742.  21517902.  21580542.  21577006.]
    print 'npy.take(lat, ind)',npy.take(lat, ind)   #Example output [ 21398764.  21459962.  21520490.  21391092.  21454742.  21517902.  21580542.  21577006.]

    #Will need to reverse back from basemap lat,lon to normal but that is easy


fig = figure()
ax1 = fig.add_subplot(111)


map1 = Basemap(projection='mill',lon_0=0, ax=ax1)

map1.drawmapboundary(fill_color='#9999FF')
##mapping coordinates according to basemap
lon,lat=map1(lon,lat)

ax1.scatter(lon,lat,c=index,cmap=mpl.cm.get_cmap('jet'),picker=1)

fig.canvas.mpl_connect('pick_event', onpick3)

plt.show()

非常感谢你的帮助！

Answer 1

我可能是一个非常复杂的方式，但事实证明，当我徘徊（放大地图）时它只记录了一个点）但是当我离得太远时，这个点包含几个，此时，鉴于地图的密度并且没有区别，我只选择了列表中的第一个索引。

def hover(event):

    #Returns a dictionary
    cont, ind = sc.contains(event)

    #Turn dictionary into a list
    myList = []  
    for k,v in ind.items():
        myList.append(v[0])

    #Take first element as it really doesn't matter, as the indexes are so close together 
    ind=myList[0]
fig1.canvas.mpl_connect("motion_notify_event", hover)

Onpick3悬停最近的数据点而不是列表

1 个答案: