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Export time dimension NetCDF to raster format using ArcPy

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06-11-2018 05:06 AM
ShouvikJha
Frequent Contributor

I have single NetCDF file which is time dimension NetCDF file, the netCDF file contains the monthly weather data for 20 years. I want to convert the NetCDF to raster tiff format and output of the raster as same the month and year name. below is code but it's producing the error in line number 29. Time format of the data is YY-MM-DD 2013-01-01 12:00, 2013-02-01 12:00, so on. How to loop all the time dimension.  

updated download link for input files: 2013.nc - Google Drive 

I tried to extract the layer manually using ArcGIS tool, it's successfully extracted. I have copied the code from ArcGIS 

arcpy.MakeNetCDFRasterLayer_md(in_netCDF_file="E:/Weather/2002.nc",
variable="slhf",
x_dimension="longitude",
y_dimension="latitude",
out_raster_layer="sshf_Layer",
band_dimension="",
dimension_values="time '01-01-2013 12:00:00'",
value_selection_method="BY_VALUE")‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍
# Import system modules
import arcpy
from arcpy import env
from arcpy.sa import *

#Workspace
outLoc = r"E:\Weather/"
inNetCDF = r"E:\Weather\2002.nc"
#Veriable
variable = "slhf"
x_dimension = "lon"
y_dimension = "lat"
band_dimension = ""
dimension = "time"
valueSelectionMethod = "BY_VALUE"

nc_FP = arcpy.NetCDFFileProperties(inNetCDF)
nc_Dim = nc_FP.getDimensions()

for dimension in nc_Dim:
        if dimension == "time":
            top = nc_FP.getDimensionSize(dimension)
            for i in range(0, top):

                dimension_values = nc_FP.getDimensionValue(dimension, i)
                nowFile = str(dimension_values)
                nowFile = nowFile.translate(None, '/')
                # I needed after 2013
                if int(nowFile.split()[0].split('-')[-1])==2013:

                    dv1 = ["time", dimension_values]
                    dimension_values = [dv1]

                    arcpy.MakeNetCDFRasterLayer_md(inNetCDF, variable, x_dimension, y_dimension, nowFile, band_dimension, dimension_values, valueSelectionMethod)
                    print "success"
                    outname = outLoc + nowFile

                    arcpy.CopyRaster_management(nowFile, outname,"", "", "", "NONE", "NONE", "")


                else: print "DATA OUT OF RANGE"‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Error message

ExecuteError: Failed to execute. Parameters are not valid.
ERROR 000237: One or more dimensions are invalid
ERROR 000237: One or more dimensions are invalid
Failed to execute (MakeNetCDFRasterLayer).‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍
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1 Solution

Accepted Solutions
XanderBakker
Esri Esteemed Contributor

Could you try the code below (changing the paths to the input NC file and output products)?

def main():
    # Import system modules
    import arcpy
    import os
    arcpy.env.overwriteOutput = True

    #Workspace
    outLoc = r"C:\GeoNet\NetCDF"
    inNetCDF = r"C:\GeoNet\NetCDF\2013.nc"
    #Veriable
    variable = "slhf"
    x_dimension = "longitude"
    y_dimension = "latitude"
    band_dimension = ""
    dimension = "time"
    valueSelectionMethod = "BY_VALUE"

    nc_FP = arcpy.NetCDFFileProperties(inNetCDF)
    print "nc_FP:", nc_FP
    nc_Dim = nc_FP.getDimensions()
    print "nc_Dim:", nc_Dim

    for dimension in nc_Dim:
        print "dimension:", dimension
        if dimension == "time":
            top = nc_FP.getDimensionSize(dimension)
            print "top:", top
            for i in range(0, top):
                print "i", i
                dimension_values = nc_FP.getDimensionValue(dimension, i)
                year = GetYear(dimension_values)
                print "year:", year
                name = GetNameOutputFile(dimension_values)
                print "name:", name

                if year == '2013':
                    dv1 = "time '{}'".format(dimension_values)
                    # dv1 = ["time", dimension_values]
                    # dimension_values = [dv1]
                    out_ras_lay = "sshf_{}".format(name)

                    arcpy.MakeNetCDFRasterLayer_md(inNetCDF, variable, x_dimension, y_dimension, out_ras_lay, band_dimension, dv1, valueSelectionMethod)
                    print "success"
                    out_name =  "{}.tif".format(out_ras_lay)
                    out_ras = os.path.join(outLoc, out_name)
                    print "out_name:", out_name
                    print "out_ras:", out_ras

                    arcpy.CopyRaster_management(out_ras_lay, out_ras,"", "", "", "NONE", "NONE", "")
                    print "CopyRaster OK..."

                else:
                    print "DATA OUT OF RANGE"



def GetNameOutputFile(dimension_value):
    dct_ampm = {'P.':'PM', 'A.':'AM', 'PM': 'PM', 'AM': 'AM'}
    lst1 = dimension_value.split(' ')
    if '/' in dimension_value:
        lst2a = lst1[0].split('/')
        lst2b = lst1[1].split(':')
        lst2a = CorrectList(lst2a)
        lst2b = CorrectList(lst2b)
        if len(lst1) >= 3:
            ampm = lst1[2].upper()
            if ampm in dct_ampm:
                ampm = dct_ampm[ampm]
            else:
                ampm = 'XX'
            name = 'd{}{}{}_t{}{}{}'.format(lst2a[2], lst2a[1], lst2a[0], lst2b[0], lst2b[1], ampm)
        else:
            name = 'd{}{}{}_t{}{}'.format(lst2a[2], lst2a[1], lst2a[0], lst2b[0], lst2b[1])

    elif '-' in dimension_value:
        lst2a = lst1[0].split('-')
        lst2b = lst1[1].split(':')
        name = 'd{}{}{}_t{}{}'.format(lst2a[2], lst2a[1], lst2a[0], lst2b[0], lst2b[1])
    else:
        name = 'd18990101_t0000'
    return name


def GetYear(dimension_value):
    lst1 = dimension_value.split(' ')
    if '/' in dimension_value:
        year = lst1[0].split('/')[2]
    elif '-' in dimension_value:
        year = lst1[0].split('-')[2]
    else:
        year = '1899'
    return year


def CorrectList(lst2a):
    lst = []
    for a in lst2a:
        if len(a) == 1:
            lst.append('0{}'.format(a))
        else:
            lst.append(a)
    return lst


if __name__ == '__main__':
    main()

View solution in original post

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24 Replies
DanPatterson_Retired
MVP Emeritus

/blogs/dan_patterson/2016/08/14/script-formatting It is hard to read and your for loops look they are suffering from a bad copy paste into the code formatter

What are your dimensions? Why not print them out since at least one of them is apparently wrong.

ShouvikJha
Frequent Contributor

i have updated the code formatting and chosen Python format. 
Regarding dimension, I have time dimension NetCDF file, based on each time file i am trying to export it as a raster. 

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DanPatterson_Retired
MVP Emeritus

print the dimensions as you get them in and around line 17-18 since one of your dimensions is wrong.

your indentation is wrong... just changing the parser to Python after the fact won't correct the script, you have to recopy and repaste

ShouvikJha
Frequent Contributor

Dan Patterson‌, Thank you. I have added the print statement but the print statement now showing any dimension of NetCDF. I have tried to convert the single layer of NetCDF file to raster using ArcGIS, its successful run. I have copied the code from ArcGIS.

arcpy.MakeNetCDFRasterLayer_md(in_netCDF_file="E:/Weather/2002.nc", variable="slhf", x_dimension="longitude", y_dimension="latitude", out_raster_layer="sshf_Layer", band_dimension="", dimension_values="time '01-01-2013 12:00:00'", value_selection_method="BY_VALUE")

but i have huge layer in NetCDF file, how to loop through all layer and convert it to raster 

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DanPatterson_Retired
MVP Emeritus

Can you show the updated code with the print statements and what it is actually printing (not the 'success' print) since one of the dimension names is invalid if the error is still the same)

For instance

x_dimension = "lon"
y_dimension = "lat"

should have been longitude and latitude as in you correct run

also

dv1 = ["time", dimension_values]
dimension_values = [dv1]

why did you make this a list of a list ? since dv1 is already a list

XanderBakker
Esri Esteemed Contributor

I would really like to know what the variable "nowFile" is filled with (if it gets there). Adding some print statements would really help and sharing the complete error message (including the line numbers) would help to understand where things go wrong. 

Is it possible to attach the nc file?

ShouvikJha
Frequent Contributor

Xander Bakker‌ Thank you. I have added the download link with my question for my input file. Kindly check it. 

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DanPatterson_Retired
MVP Emeritus

Can you run this from your IDE's command line as well to get a listing of the dimensions

import netCDF4

f = r"C:\path\your_netcdf.nc"  # change to match one of your nc files
dataset = netCDF4.Dataset(f)
dataset.dimensions


# ----- report the list that is returned
XanderBakker
Esri Esteemed Contributor

I just changed some code and did a test and it does produce several rasters. See code below:

# Import system modules
import arcpy
import os

#Workspace
outLoc = r"C:\GeoNet\NetCDF"
inNetCDF = r"C:\GeoNet\NetCDF\2013.nc"
#Veriable
variable = "slhf"
x_dimension = "longitude"  # Changed!
y_dimension = "latitude"  # Changed!
band_dimension = ""
dimension = "time"
valueSelectionMethod = "BY_VALUE"

nc_FP = arcpy.NetCDFFileProperties(inNetCDF)
print "nc_FP:", nc_FP
nc_Dim = nc_FP.getDimensions()
print "nc_Dim:", nc_Dim

for dimension in nc_Dim:
    print "dimension:", dimension
    if dimension == "time":
        top = nc_FP.getDimensionSize(dimension)
        print "top:", top
        for i in range(0, top):
            print "i", i
            dimension_values = nc_FP.getDimensionValue(dimension, i)
            print "dimension_values", dimension_values
            nowFile = str(dimension_values)
            print "nowFile (1):", nowFile
            nowFile = nowFile.translate(None, '/')
            print "nowFile (2):", nowFile

            # I needed after 2013
            test = int(nowFile.split()[0].split('-')[-1])
            print "test", test
            if int(nowFile.split()[0].split('-')[-1])==4021900:  # 2013
                dv1 = "time '{}'".format(dimension_values)
                # dv1 = ["time", dimension_values]
                # dimension_values = [dv1]
                out_ras_lay = "sshf_Layer_{}".format(i)

                arcpy.MakeNetCDFRasterLayer_md(inNetCDF, variable, x_dimension, y_dimension, out_ras_lay, band_dimension, dv1, valueSelectionMethod)
                print "success"
                out_name =  "{}.tif".format(out_ras_lay)
                out_ras = os.path.join(outLoc, out_name)
                print "out_name:", out_name
                print "out_ras:", out_ras

                arcpy.CopyRaster_management(out_ras_lay, out_ras,"", "", "", "NONE", "NONE", "")
                print "CopyRaster OK..."

            else:
                print "DATA OUT OF RANGE"

A number of things that caused problems, for instance:

  • dimensions X and Y did not have the correct names on lines 10 and 11
  • On line 38 (in my code) the validation was against 2013, however the year of the dates in the provided NC file was 1900. It never reached the part that converts to raster
  • The dimension values were not correctly formatted (I'm using line 39)
  • I changed the output raster layer name to a different unique name, which does not generate problems
  • I also changed the output rasters names to avoid problems. 

A resulting raster (12 were created):