ref: move grib file manipulation into services

dev
g 4 years ago
parent 013accefef
commit 1b4e362ce5

@ -51,7 +51,7 @@ async def get_test():
@app.get("/download/")
async def download_grib(background_tasks: BackgroundTasks):
"""Download and process GRIB files into csv of requested parameters"""
background_tasks.add_task(extract_useful_data)
background_tasks.add_task(service_grib.extract_useful_data)
return JSONResponse(content={"status": "Background task started"})
@ -61,138 +61,3 @@ async def download_grib(background_tasks: BackgroundTasks):
@repeat_every(seconds=(1 * 60))
async def task_gc() -> None:
gc.collect()
def fresh_grib_time(target_time=None):
"""Find most recent available GRIB file
for GFS atmospheric and GFSWave forecasts
:param target_time: no more recent than this time
:returns: most recent time GRIB is available
"""
if not target_time:
target_time = datetime.now(
tz=ZoneInfo("US/Eastern")
) # noaa is located in washington
for fallback in range(4):
# wasting a bit of time here on useless first cycle (mult by 0, subtract 0)
# allows us to kepp code a bit neater later
fallback_hours = fallback * 6
target_time = target_time - timedelta(hours=fallback_hours)
if not service_grib.is_reachable(
service_grib.form_gfs_link(target_time=target_time, prod_hour=384)
):
continue
if not service_grib.is_reachable(
service_grib.form_gfswave_link(target_time=target_time, prod_hour=384)
):
continue
break
else:
raise Exception("No forecasts in the last 24 hours were reachable")
# both forecasts are reachable @ target_time
return target_time
def download_fresh_grib(target_time, prod_hour=0):
"""Download GRIB files for atmos and wave
:param target_time: download GRIB from this time
:param prod_hour: download forecast for this hour
:returns: filenames where GRIB files are downloaded to
"""
gfs_atmos = service_grib.form_gfs_link(target_time=target_time, prod_hour=prod_hour)
gfs_wave = service_grib.form_gfswave_link(
target_time=target_time, prod_hour=prod_hour
)
return (
wget.download(gfs_atmos, out=SAVE_DIR),
wget.download(gfs_wave, out=SAVE_DIR),
)
def extract_useful_data():
"""Download and process GRIB files into csv of requested parameters
:returns: filenames of the resulting csv
"""
target_time = fresh_grib_time()
save_to = f"{target_time.strftime('%Y%m%d')}-{str((target_time.hour // 6) * 6).zfill(2)}.csv"
for forecast_hour in range(MAX_FORECAST_HOUR):
# download gribs
ds_atmos_file, ds_wave_file = download_fresh_grib(
target_time=target_time, prod_hour=forecast_hour
)
# filter atmos to requested variables
with xr.open_dataset(ds_atmos_file, engine="pynio") as ds_atmos:
filtered_ds_atmos = ds_atmos.get(ATMOS_PARAM_NAMES) or ds_atmos.get(
[p for p in ATMOS_PARAM_NAMES if not p == "APCP_P8_L1_GLL0_acc"]
) # skip running total column in the first forecast
for name, param in HEIGHT_PARAM_NAMES.items():
if name == "TMP_P0_L103_GLL0":
level = TEMPERATURE_HEIGHT
else:
level = WIND_HEIGHT
filtered_ds_atmos[name] = (
ds_atmos[name]
.sel({param: level})
.assign_attrs(level=level)
.drop_vars(param)
)
# if hour==0 add running total column from future forecasts
if forecast_hour == 0:
precip = xr.zeros_like(filtered_ds_atmos["GUST_P0_L1_GLL0"])
precip.name = "APCP_P8_L1_GLL0_acc"
filtered_ds_atmos = xr.combine_by_coords(
[filtered_ds_atmos, precip], coords="mimal"
)
# filter wave to requested variables
with xr.open_dataset(ds_wave_file, engine="pynio") as ds_wave:
filtered_ds_wave = ds_wave.get(WAVE_PARAM_NAMES)
# concatinate atmos and wave into a single dataset
combined_product = filtered_ds_atmos.merge(
filtered_ds_wave.reindex_like(filtered_ds_atmos, method="nearest")
)
# transfer to pandas
df = combined_product.to_dataframe()
# convert longitude values into the standard range of -180 degrees to +180 degrees
# TODO: do we want to do it?
latitudes = df.index.get_level_values("lat_0")
longitudes = df.index.get_level_values("lon_0")
map_function = lambda lon: (lon - 360) if (lon > 180) else lon
remapped_longitudes = longitudes.map(map_function)
df["longitude"] = remapped_longitudes
df["latitude"] = latitudes
# dump datafrate to csv on disk
if forecast_hour == 0:
df.to_csv(
os.path.join(
SAVE_DIR,
save_to,
),
index=False,
)
else:
df.to_csv(
os.path.join(SAVE_DIR, save_to),
index=False,
mode="a",
header=False,
)
# clean up grib files
os.remove(ds_wave_file)
os.remove(ds_atmos_file)
return save_to

@ -56,3 +56,138 @@ class Grib:
hour_str = str((target_time.hour // 6) * 6).zfill(2)
target_url = f"https://nomads.ncep.noaa.gov/pub/data/nccf/com/gfs/prod/gfs.{date_str}/{hour_str}/{looking_at}/gridded/gfs{looking_at}.t{hour_str}z.global.0p25.f{prod_hour}.grib2"
return target_url
@staticmethod
def fresh_grib_time(target_time=None):
"""Find most recent available GRIB file
for GFS atmospheric and GFSWave forecasts
:param target_time: no more recent than this time
:returns: most recent time GRIB is available
"""
if not target_time:
target_time = datetime.now(
tz=ZoneInfo("US/Eastern")
) # noaa is located in washington
for fallback in range(4):
# wasting a bit of time here on useless first cycle (mult by 0, subtract 0)
# allows us to kepp code a bit neater later
fallback_hours = fallback * 6
target_time = target_time - timedelta(hours=fallback_hours)
if not Grib.is_reachable(
Grib.form_gfs_link(target_time=target_time, prod_hour=384)
):
continue
if not Grib.is_reachable(
Grib.form_gfswave_link(target_time=target_time, prod_hour=384)
):
continue
break
else:
raise Exception("No forecasts in the last 24 hours were reachable")
# both forecasts are reachable @ target_time
return target_time
@staticmethod
def download_fresh_grib(target_time, prod_hour=0):
"""Download GRIB files for atmos and wave
:param target_time: download GRIB from this time
:param prod_hour: download forecast for this hour
:returns: filenames where GRIB files are downloaded to
"""
gfs_atmos = Grib.form_gfs_link(target_time=target_time, prod_hour=prod_hour)
gfs_wave = Grib.form_gfswave_link(target_time=target_time, prod_hour=prod_hour)
return (
wget.download(gfs_atmos, out=SAVE_DIR),
wget.download(gfs_wave, out=SAVE_DIR),
)
@staticmethod
def extract_useful_data():
"""Download and process GRIB files into csv of requested parameters
:returns: filenames of the resulting csv
"""
target_time = Grib.fresh_grib_time()
save_to = f"{target_time.strftime('%Y%m%d')}-{str((target_time.hour // 6) * 6).zfill(2)}.csv"
for forecast_hour in range(MAX_FORECAST_HOUR):
# download gribs
ds_atmos_file, ds_wave_file = Grib.download_fresh_grib(
target_time=target_time, prod_hour=forecast_hour
)
# filter atmos to requested variables
with xr.open_dataset(ds_atmos_file, engine="pynio") as ds_atmos:
filtered_ds_atmos = ds_atmos.get(ATMOS_PARAM_NAMES) or ds_atmos.get(
[p for p in ATMOS_PARAM_NAMES if not p == "APCP_P8_L1_GLL0_acc"]
) # skip running total column in the first forecast
for name, param in HEIGHT_PARAM_NAMES.items():
if name == "TMP_P0_L103_GLL0":
level = TEMPERATURE_HEIGHT
else:
level = WIND_HEIGHT
filtered_ds_atmos[name] = (
ds_atmos[name]
.sel({param: level})
.assign_attrs(level=level)
.drop_vars(param)
)
# if hour==0 add running total column from future forecasts
if forecast_hour == 0:
precip = xr.zeros_like(filtered_ds_atmos["GUST_P0_L1_GLL0"])
precip.name = "APCP_P8_L1_GLL0_acc"
filtered_ds_atmos = xr.combine_by_coords(
[filtered_ds_atmos, precip], coords="mimal"
)
# filter wave to requested variables
with xr.open_dataset(ds_wave_file, engine="pynio") as ds_wave:
filtered_ds_wave = ds_wave.get(WAVE_PARAM_NAMES)
# concatinate atmos and wave into a single dataset
combined_product = filtered_ds_atmos.merge(
filtered_ds_wave.reindex_like(
filtered_ds_atmos, method="nearest"
)
)
# transfer to pandas
df = combined_product.to_dataframe()
# convert longitude values into the standard range of -180 degrees to +180 degrees
# TODO: do we want to do it?
latitudes = df.index.get_level_values("lat_0")
longitudes = df.index.get_level_values("lon_0")
map_function = lambda lon: (lon - 360) if (lon > 180) else lon
remapped_longitudes = longitudes.map(map_function)
df["longitude"] = remapped_longitudes
df["latitude"] = latitudes
# dump datafrate to csv on disk
if forecast_hour == 0:
df.to_csv(
os.path.join(
SAVE_DIR,
save_to,
),
index=False,
)
else:
df.to_csv(
os.path.join(SAVE_DIR, save_to),
index=False,
mode="a",
header=False,
)
# clean up grib files
os.remove(ds_wave_file)
os.remove(ds_atmos_file)
return save_to

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