2
海洋波動測定期間の「単位」属性は「秒」です。これはdatetimeフィールドではありませんが、xarrayはこの変数をtimedelta64として自動的に取り込みます。ユニットは "〜からの秒数"ではないので、xarrayはこれを通常のfloat32データ配列として扱うはずですが、そうではないようです。波の周期変数をfloat32として取り込むか、取り込み後timedelta64から元の値に戻すようにxarrayに指示する方法はありますか？私はまだ "time"変数をtimedelta64に変換したいので、特定の変数（Tper、sper、wper）だけを対象にして、データセット全体の翻訳をオフにしたくありません。xarray波の周期（秒単位）timedelta64
提案：ここ
は、私たちのTDSサーバに波予報からで働いていますベースOPeNDAPのURLのですか？ありがとう！
あなたがここにOPeNDAPページを使用して出力様 "ncdump" を参照してくださいすることができます
それとも、そのようOPeNDAP URLにncdump実行することができます：http://oos.soest.hawaii.edu/thredds/dodsC/hioos/model/wav/ww3/hawaii/WaveWatch_III_Hawaii_Regional_Wave_Model_best.ncd
-hncdump以下で
この結果：
netcdf WaveWatch_III_Hawaii_Regional_Wave_Model_best {
dimensions:
lat = 101 ;
lon = 141 ;
time = 54453 ;
z = 1 ;
variables:
float lon(lon) ;
lon:units = "degrees_east" ;
lon:long_name = "longitude" ;
lon:standard_name = "longitude" ;
lon:short_name = "lon" ;
lon:axis = "x" ;
lon:_CoordinateAxisType = "Lon" ;
float lat(lat) ;
lat:units = "degrees_north" ;
lat:long_name = "latitude" ;
lat:standard_name = "latitude" ;
lat:short_name = "lat" ;
lat:axis = "y" ;
lat:_CoordinateAxisType = "Lat" ;
float z(z) ;
z:units = "meters" ;
z:long_name = "depth below mean sea level" ;
z:standard_name = "depth" ;
z:short_name = "depth" ;
z:axis = "z" ;
z:_CoordinateAxisType = "Height" ;
double time(time) ;
time:long_name = "Forecast time for ForecastModelRunCollection" ;
time:standard_name = "time" ;
time:calendar = "proleptic_gregorian" ;
time:units = "hours since 2011-06-21 00:00:00.000 UTC" ;
time:missing_value = NaN ;
time:_CoordinateAxisType = "Time" ;
double time_run(time) ;
time_run:long_name = "run times for coordinate = time" ;
time_run:standard_name = "forecast_reference_time" ;
time_run:calendar = "proleptic_gregorian" ;
time_run:units = "hours since 2011-06-21 00:00:00.000 UTC" ;
time_run:missing_value = NaN ;
time_run:_CoordinateAxisType = "RunTime" ;
double time_offset(time) ;
time_offset:long_name = "offset hour from start of run for coordinate = time" ;
time_offset:standard_name = "forecast_period" ;
time_offset:calendar = "proleptic_gregorian" ;
time_offset:units = "hours since 2011-06-21T00:00:00Z" ;
time_offset:missing_value = NaN ;
float Thgt(time, z, lat, lon) ;
Thgt:units = "meters" ;
Thgt:long_name = "significant wave height" ;
Thgt:standard_name = "sea_surface_wave_significant_height" ;
Thgt:short_name = "Thgt" ;
Thgt:valid_range = 0.f, 60.f ;
Thgt:_FillValue = NaNf ;
Thgt:coordinates = "time_run time z lat lon " ;
float Tper(time, z, lat, lon) ;
Tper:units = "seconds" ;
Tper:long_name = "peak wave period" ;
Tper:standard_name = "sea_surface_wave_period_at_variance_spectral_density_maximum" ;
Tper:short_name = "Tper" ;
Tper:valid_range = 0.f, 60.f ;
Tper:_FillValue = NaNf ;
Tper:coordinates = "time_run time z lat lon " ;
float Tdir(time, z, lat, lon) ;
Tdir:units = "degrees" ;
Tdir:long_name = "peak wave direction" ;
Tdir:standard_name = "sea_surface_wave_from_direction" ;
Tdir:short_name = "Tdir" ;
Tdir:valid_range = 0.f, 360.f ;
Tdir:_FillValue = NaNf ;
Tdir:coordinates = "time_run time z lat lon " ;
float shgt(time, z, lat, lon) ;
shgt:units = "meters" ;
shgt:long_name = "swell significant wave height" ;
shgt:standard_name = "sea_surface_swell_wave_significant_height" ;
shgt:short_name = "shgt" ;
shgt:valid_range = 0.f, 60.f ;
shgt:_FillValue = NaNf ;
shgt:coordinates = "time_run time z lat lon " ;
float sper(time, z, lat, lon) ;
sper:units = "seconds" ;
sper:long_name = "swell peak wave period" ;
sper:standard_name = "sea_surface_swell_wave_period" ;
sper:short_name = "sper" ;
sper:valid_range = 0.f, 60.f ;
sper:_FillValue = NaNf ;
sper:coordinates = "time_run time z lat lon " ;
float sdir(time, z, lat, lon) ;
sdir:units = "degrees" ;
sdir:long_name = "swell peak wave direction" ;
sdir:standard_name = "sea_surface_swell_wave_from_direction" ;
sdir:short_name = "sdir" ;
sdir:valid_range = 0.f, 360.f ;
sdir:_FillValue = NaNf ;
sdir:coordinates = "time_run time z lat lon " ;
float whgt(time, z, lat, lon) ;
whgt:units = "meters" ;
whgt:long_name = "wind significant wave height" ;
whgt:standard_name = "sea_surface_wind_wave_significant_height" ;
whgt:short_name = "whgt" ;
whgt:valid_range = 0.f, 60.f ;
whgt:_FillValue = NaNf ;
whgt:coordinates = "time_run time z lat lon " ;
float wper(time, z, lat, lon) ;
wper:units = "seconds" ;
wper:long_name = "wind peak wave period" ;
wper:standard_name = "sea_surface_wind_wave_period" ;
wper:short_name = "wper" ;
wper:valid_range = 0.f, 60.f ;
wper:_FillValue = NaNf ;
wper:coordinates = "time_run time z lat lon " ;
float wdir(time, z, lat, lon) ;
wdir:units = "degrees" ;
wdir:long_name = "wind peak wave direction" ;
wdir:standard_name = "sea_surface_wind_wave_from_direction" ;
wdir:short_name = "wdir" ;
wdir:valid_range = 0.f, 360.f ;
wdir:_FillValue = NaNf ;
wdir:coordinates = "time_run time z lat lon " ;
// global attributes:
:title = "WaveWatch III (WW3) Hawaii Regional Wave Model" ;
:_CoordSysBuilder = "ucar.nc2.dataset.conv.CF1Convention" ;
:Conventions = "CF-1.6, ACDD-1.3" ;
:cdm_data_type = "Grid" ;
:featureType = "GRID" ;
:location = "Proto fmrc:WaveWatch_III_Hawaii_Regional_Wave_Model" ;
:id = "ww3_hawaii" ;
:naming_authority = "org.pacioos" ;
:Metadata_Link = "http://pacioos.org/metadata/ww3_hawaii.html" ;
:ISO_Topic_Categories = "oceans" ;
:summary = "Through a collaborative effort with NOAA/NCEP and NWS Honolulu, the University of Hawaii has implemented a global-scale WaveWatch III (WW3) model, which in turn provides boundary conditions for this Hawaii regional WW3: a 7-day model with a 5-day hourly forecast at approximately 5-km or 0.05-deg resolution. The primary purpose of this regional model is to capture island effects such as island shadowing, refraction, and accurate modeling of local wind waves. Hawaii WW3 is forced with winds from the University of Hawaii Meteorology Department\'s operational mesoscale model, which has a more suitable spatial resolution than the global scale wind field. The Hawaii regional WW3 also provides boundary conditions for nearshore island-scale models via Simulating WAves Nearshore (SWAN). While considerable effort has been made to implement all model components in a thorough, correct, and accurate manner, numerous sources of error are possible. As such, please use these data with the caution appropriate for any ocean related activity." ;
:keywords = "Earth Science Services > Models > Ocean General Circulation Models (OGCM)/Regional Ocean Models, Earth Science Services > Models > Weather Research/Forecast Models, Earth Science > Oceans > Ocean Waves > Significant Wave Height, Earth Science > Oceans > Ocean Waves > Wave Period, Earth Science > Oceans > Ocean Waves > Wave Speed/Direction" ;
:keywords_vocabulary = "GCMD Science Keywords" ;
:platform = "Models/Analyses > > Operational Models" ;
:platform_vocabulary = "GCMD Platform Keywords" ;
:instrument = "Not Applicable > Not Applicable" ;
:instrument_vocabulary = "GCMD Instrument Keywords" ;
:locations = "Continent > North America > United States Of America > Hawaii, Ocean > Pacific Ocean > Central Pacific Ocean > Hawaiian Islands" ;
:locations_vocabulary = "GCMD Location Keywords" ;
:standard_name_vocabulary = "CF Standard Name Table v39" ;
:comment = "Model runs produced by Dr. Kwok Fai Cheung ([email protected])." ;
:geospatial_lat_min = 18. ;
:geospatial_lat_max = 23. ;
:geospatial_lon_min = 199. ;
:geospatial_lon_max = 206. ;
:geospatial_vertical_min = 0. ;
:geospatial_vertical_max = 0. ;
:geospatial_bounds = "POLYGON ((18 -161.0, 23 -161.0, 23 -154.0, 18 -154.0, 18 -161.0))" ;
:geospatial_bounds_crs = "EPSG:4326" ;
:time_coverage_start = "2011-06-21T21:00:00Z" ;
:geospatial_lat_units = "degrees_north" ;
:geospatial_lat_resolution = 0.05 ;
:geospatial_lon_units = "degrees_east" ;
:geospatial_lon_resolution = 0.05 ;
:geospatial_vertical_units = "meters" ;
:geospatial_vertical_positive = "up" ;
:geospatial_vertical_resolution = 0. ;
:time_coverage_resolution = "PT1H" ;
:creator_email = "[email protected]" ;
:creator_name = "Kwok Fai Cheung" ;
:creator_type = "person" ;
:creator_url = "http://www.ore.hawaii.edu/OE/cheung_research.htm" ;
:creator_institution = "University of Hawaii" ;
:date_created = "2011-06-22" ;
:date_issued = "2011-06-22" ;
:date_modified = "2014-06-23" ;
:date_metadata_modified = "2017-01-30" ;
:institution = "University of Hawaii" ;
:project = "Pacific Islands Ocean Observing System (PacIOOS)" ;
:program = "Pacific Islands Ocean Observing System (PacIOOS)" ;
:contributor_name = "Jim Potemra" ;
:contributor_role = "distributor" ;
:publisher_email = "[email protected]" ;
:publisher_name = "Pacific Islands Ocean Observing System (PacIOOS)" ;
:publisher_url = "http://pacioos.org" ;
:publisher_institution = "University of Hawaii" ;
:publisher_type = "group" ;
:license = "The data may be used and redistributed for free but is not intended for legal use, since it may contain inaccuracies. Neither the data Contributor, University of Hawaii, PacIOOS, NOAA, State of Hawaii nor the United States Government, nor any of their employees or contractors, makes any warranty, express or implied, including warranties of merchantability and fitness for a particular purpose, or assumes any legal liability for the accuracy, completeness, or usefulness, of this information." ;
:acknowledgement = "The Pacific Islands Ocean Observing System (PacIOOS) is funded through the National Oceanic and Atmospheric Administration (NOAA) as a Regional Association within the U.S. Integrated Ocean Observing System (IOOS). PacIOOS is coordinated by the University of Hawaii School of Ocean and Earth Science and Technology (SOEST)." ;
:source = "WaveWatch III (WW3) numerical wave model" ;
:references = "http://pacioos.org/waves/model-hawaii/, http://polar.ncep.noaa.gov/waves/wavewatch/" ;
:history = "FMRC Best Dataset" ;
ありがとう、Ray）あなたの "t01"変数は "s"の単位を持ち、 "Tper"、 "sper"、 "wper"変数の単位は "秒"です。これらは同等でなければならず、問題ではありません。 Hm。私はまたあなたの "t01"変数がscale_factorとadd_offset（valid_minとvalid_maxと同様に）を適用することを知っているので、それらの属性がdatetimeフィールドとして扱わないようにxarrayをトリガーするのだろうか？ –
@JohnMaurer [nco]（http://nco.sourceforge.net/）をncatted -O -a units、Tper、o、c、 "file.nc"としてNetCDFファイルの単位を変更することができます。 "秒"の代わりに "s"が私たちの違いを引き起こしているかどうかを確認するために –
実際、私はTDSでNcMLを使ってこれを行っています。勘違いは正しかった。 「Tper」を「秒」ではなく「s」に変更すると、この波の周期変数は、時間座標ではなく、必要に応じて浮動小数点配列として扱われます。その後、xarrayの監視（バグ）のように見えます。興味深いことに、複数の "秒"の代わりに "秒"に変更すると、データが時間座標の代わりに浮動小数点配列としてインポートされます。だから唯一の厄介なエントリは "秒"です。回避策に向かって私を助けてくれてありがとう。 –