約束不匹配錯誤

我運行下面的代碼來創建一個簡單的線圖：約束不匹配錯誤

import matplotlib.pyplot as plt 
import iris 
import iris.coord_categorisation as iriscc 
import iris.plot as iplt 
import iris.quickplot as qplt 
import iris.analysis.cartography 
import matplotlib.dates as mdates 

def main(): 
    #bring in all the files we need and give them a name 
    TestFile= '/exports/csce/datastore/geos/users/s0XXXX/Climate_Modelling/AFR_44_tas/Historical/1950-2005/tas_AFR-44_MOHC-HadGEM2-ES_historical_r1i1p1_CLMcom-CCLM4-8-17_v1_mon_194912-200512.nc' 

    #Load exactly one cube from given file 
    TestFile = iris.load_cube(TestFile) 

    print TestFile 

    #adjust longitude as data is out by 180degrees 
    #remove flat latitude and longitude and only use grid latitude and grid longitude which are in the 3rd and 4th column of the file 

    lats = iris.coords.DimCoord(TestFile.coords()[3].points[:,0], \ 
           standard_name='latitude', units='degrees') 
    lons = TestFile.coords()[4].points[0] 
    for i in range(len(lons)): 
     if lons[i]>100.: 
      lons[i] = lons[i]-360. 
    lons = iris.coords.DimCoord(lons, \ 
           standard_name='longitude', units='degrees') 
    TestFile.remove_coord('latitude') 
    TestFile.remove_coord('longitude') 
    TestFile.remove_coord('grid_latitude') 
    TestFile.remove_coord('grid_longitude') 
    TestFile.add_dim_coord(lats, 1) 
    TestFile.add_dim_coord(lons, 2) 

    #we are only interested in the latitude and longitude relevant to Malawi 

    Malawi = iris.Constraint(longitude=lambda v: 32.5 <= v <= 36., \ 
         latitude=lambda v: -17. <= v <= -9.) 

    TestFile = TestFile.extract(Malawi) 

    #data is in Kelvin, but we would like to show it in Celcius 
    TestFile.convert_units('Celsius') 

    #We are interested in plotting the graph with time along the x ais, so we need a mean of all the coordinates, i.e. mean temperature across whole country  
    iriscc.add_year(TestFile, 'time') 

    TestFile = TestFile.aggregated_by('year', iris.analysis.MEAN) 

    TestFile.coord('latitude').guess_bounds() 
    TestFile.coord('longitude').guess_bounds() 
    TestFile_grid_areas = iris.analysis.cartography.area_weights(TestFile) 
    TestFile_mean = TestFile.collapsed(['latitude', 'longitude'], 
                iris.analysis.MEAN, 
                weights=TestFile_grid_areas) 


    #set major plot indicators for x-axis            
    plt.gca().xaxis.set_major_locator(mdates.YearLocator(5)) 

    #assign the line colours 
    qplt.plot(TestFile_mean, label='TestFile', lw=1.5, color='blue') 

    #create a legend and set its location to under the graph 
    plt.legend(loc="upper center", bbox_to_anchor=(0.5,-0.05), fancybox=True, shadow=True, ncol=5) 

    #create a title 
    plt.title('Mean Near Surface Temperature for Malawi', fontsize=11) 

    #create the graph 
    plt.grid() 

    iplt.show() 

if __name__ == '__main__': 
    main()

這對於大多數文件的工作很好，但有兩個氣候模式，是未來與約束不匹配錯誤：

runfile('/exports/csce/datastore/geos/users/s0XXXX/Climate_Modelling/Python Code and Output Images/Line_Graph_Temp_Test.py', wdir='/exports/csce/datastore/geos/users/s0XXXX/Climate_Modelling/Python Code and Output Images') 
Traceback (most recent call last): 

File "<ipython-input-83-4f4457568a8f>", line 1, in <module>  runfile('/exports/csce/datastore/geos/users/s0XXXX/Climate_Modelling/Python Code and Output Images/Line_Graph_Temp_Test.py', wdir='/exports/csce/datastore/geos/users/s0XXXX/Climate_Modelling/Python Code and Output Images')  

File "/usr/lib/python2.7/site-packages/spyderlib/widgets/externalshell/sitecustomize.py", line 685, in runfile  
execfile(filename, namespace) 

File "/usr/lib/python2.7/site-packages/spyderlib/widgets/externalshell/sitecustomize.py", line 78, in execfile 
builtins.execfile(filename, *where)  

File "/exports/csce/datastore/geos/users/s0XXXX/Climate_Modelling/Python Code and Output Images/Line_Graph_Temp_Test.py", line 84, in <module> 
main() 

File "/exports/csce/datastore/geos/users/s0XXXX/Climate_Modelling/Python Code and Output Images/Line_Graph_Temp_Test.py", line 21, in main  
TestFile = iris.load_cube(TestFile)  

File "/usr/lib64/python2.7/site-packages/iris/__init__.py", line 338, in load_cube  
raise iris.exceptions.ConstraintMismatchError(str(e))   

ConstraintMismatchError: failed to merge into a single cube.  
    cube.standard_name differs: None != u'air_temperature'  
    cube.long_name differs: None != u'Near-Surface Air Temperature' 
    cube.var_name differs: u'rotated_pole' != u'tas' 
    cube.units differs: Unit('no_unit') != Unit('K') 
    cube.attributes keys differ: 'grid_north_pole_latitude', 'grid_north_pole_longitude', 'grid_mapping_name' 
    cube.cell_methods differ 
    cube.shape differs:() != (660, 201, 194) 
    cube data dtype differs: |S1 != float32 
    cube data fill_value differs: '\x00' != 1e+20

同樣，我在嘗試運行觀測數據時，這個錯誤（cru_ts4.00.1901.2015.tmp.dat.nc）

ConstraintMismatchError: failed to merge into a single cube. 
    cube.long_name differs: u'near-surface temperature' != None 
    cube.var_name differs: u'tmp' != u'stn' 
    cube.units differs: Unit('degrees Celsius') != Unit('1') 
    cube.attributes keys differ: 'correlation_decay_distance', 'description' 
    cube data dtype differs: float32 != int32 
    cube data fill_value differs: 9.96921e+36 != -2147483647

關於我如何解決這個問題的任何想法？

來源

2017-08-16 ErikaAWT

感謝您的編輯@jps – ErikaAWT

我收到了Andrew Dawson對Iris User Google Group的回覆。如果對別人有幫助，請在這裏發帖。這幫助了我！

函數iris.load_cube用於從給定文件中加載恰好1個且僅有1個立方體的匹配給定約束。您沒有提供約束條件，這意味着您期望您加載的文件減少到1個立方體。來自iris.load_cube的ConstraintMismatchError告訴你，由於一些不匹配的數據，這是不可能的。從錯誤看來，您的輸入文件中有多個變量用於這些模型。你應該考慮加載時，也許比如增加一個明確的約束：

iris.load_cube(filename, 'name_of_variable_here')

其中NAME_OF_VARIABLE應該是立方體將裝有名字，即cube.name的結果（）。這與netcdf變量名稱不同。爲了工作，你需要如何做到這一點，我建議從有問題的數據集的一個加載所有立方體與

cubes = iris.load(the_filename) # load all the cubes in the input file

，然後打印立方體

多維數據集在多維數據集的名稱：

print(cube.name())

來源

2017-08-16 15:06:32 ErikaAWT

約束不匹配錯誤

回答

相關問題