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wrf_wps_read_int

Reads data from a WPS intermediate file.

Available in version 6.3.0 and later.

Prototype

	function wrf_wps_read_int (
		filename [1] : string 
	)
	return_val [nfields][ny][nx] : float

Arguments

filename

The name of the WPS intermediate file to read.

Description

This function reads data from the given WPS intermediate file, and returns a 3D float array dimensioned [nfields x ny x nx], where each [ny x nx] subset is a 2D field that was written to the file.

It also returns several attributes attached to the return variable, each one a string array of length nfields containing information about each field:

hdate the date for each field field the field name for each field units the units for each field description a description for each field map_source a map source for each field

A 2D float attribute called rhead of size nfields x 14 is returned that contains the following values:

For all fields:
version	rhead(:,0)
forecast hour	rhead(:,1)
level	rhead(:,2)
nx	rhead(:,3)
ny	rhead(:,4)
projection (0, 1, 3, 4, or 5)	rhead(:,5)
If projection = 0:
startlat	rhead(:,6)
startlon	rhead(:,7)
deltalat	rhead(:,8)
deltalon	rhead(:,9)
earth_radius	rhead(:,10)
If projection = 1:
startlat	rhead(:,6)
startlon	rhead(:,7)
dx	rhead(:,8)
dy	rhead(:,9)
truelat1	rhead(:,10)
earth_radius	rhead(:,11)
If projection = 3:
startlat	rhead(:,6)
startlon	rhead(:,7)
dx	rhead(:,8)
dy	rhead(:,9)
center_lon	rhead(:,10)
truelat1	rhead(:,11)
truelat2	rhead(:,12)
earth_radius	rhead(:,13)
If projection = 4:
startlat	rhead(:,6)
startlon	rhead(:,7)
nlats	rhead(:,8)
deltalon	rhead(:,9)
earth_radius	rhead(:,10)
If projection = 5:
startlat	rhead(:,6)
startlon	rhead(:,7)
dx	rhead(:,8)
dy	rhead(:,9)
center longitude	rhead(:,10)
truelat1	rhead(:,11)
earth_radius	rhead(:,12)

To read a WPS file one field at a time, you can use a 3-step process:

wrf_wps_open_int - open a WPS file
wrf_wps_rdhead_int - read header info for current field
wrf_wps_rddata_int - read data for current field

The examples below illustrate both methods for reading a WPS file.

Examples

Example 1

This example shows how to use wrf_wps_read_int to read a WPS intermediate file in one step.

See example 2 below for a script that shows a three-step process of reading a WPS file using 1) wrf_wps_open_int, 2) wrf_wps_rdhead_int, and 3) wrf_wps_rddata_int.

 wps_filename = "NNRP:2006年04月10日_00"
 slabs = wrf_wps_read_int(wps_filename)
 slabs_dims = dimsizes(slabs)
 header = slabs@rhead ; Read into memory so we can subscript it
 nfields = slabs_dims(0)
 print("There are " + nfields + " fields in the " + wps_filename + " WPS file.")
 do nf=0,nfields-1
;---Print information about each slab
 print("Field #" + (nf+1))
 print(" name : '" + slabs@field(nf) + "'")
 print(" description : '" + slabs@description(nf) + "'")
 print(" units : '" + slabs@units(nf) + "'")
 print(" min/max value : " + min(slabs(nf,:,:)) + " / " + max(slabs(nf,:,:)))
 print(" date : '" + slabs@hdate(nf) + "'")
 print(" map source : '" + slabs@map_source(nf) + "'")
 print(" version : " + header(nf,0))
 print(" forecast hour : " + header(nf,1))
 print(" level : " + header(nf,2))
 print(" ny x nx : " + header(nf,4) + " x " + header(nf,3))
 print(" projection : " + header(nf,5))
 if(header(nf,5).eq.0) then
 print("startlat : " + header(nf,6))
 print(" startlon : " + header(nf,7))
 print(" deltalat : " + header(nf,8))
 print(" deltalon : " + header(nf,9))
 print(" earth_radius : " + header(nf,10))
 else if(header(nf,5).eq.1) then
 print(" startlat : " + header(nf,6))
 print(" startlon : " + header(nf,7))
 print(" dy x dx : " + header(nf,9) + " x " + header(nf,8))
 print(" truelat1 : " + header(nf,10))
 print(" earth_radius : " + header(nf,11))
 else if(header(nf,5).eq.3) then
 print(" startlat : " + header(nf,6))
 print(" startlon : " + header(nf,7))
 print(" dy x dx : " + header(nf,9) + " x " + header(nf,8))
 print(" center lon : " + header(nf,10))
 print(" truelat1 : " + header(nf,11))
 print(" truelat2 : " + header(nf,12))
 print(" earth_radius : " + header(nf,13))
 else if(header(nf,5).eq.4) then
 print(" startlat : " + header(nf,6))
 print(" startlon : " + header(nf,7))
 print(" nlats : " + header(nf,8))
 print(" deltalon : " + header(nf,9))
 print(" earth_radius : " + header(nf,10))
 else if(header(nf,5).eq.5) then
 print(" startlat : " + header(nf,6))
 print(" startlon : " + header(nf,7))
 print(" dy x dx : " + header(nf,9) + " x " + header(nf,8))
 print(" center lon : " + header(nf,10))
 print(" truelat1 : " + header(nf,11))
 print(" earth_radius : " + header(nf,12))
 end if
 end if
 end if
 end if
 end if
 end do

Output: (run with "-n" option to remove annoying "(0)")

There are 100 fields in the NNRP:2006年04月10日_00 WPS file.
Field #1
 name : 'PMSL'
 description : 'Sea-level Pressure'
 units : 'Pa'
 min/max value : 0 / 107780
 date : '2006-04-10_00:00:00'
 map source : 'unknown model from NCEP GRID 2'
 version : 5
 forecast hour : 0
 level : 201300
 ny x nx : 73 x 144
 projection : 0
 startlat : 90
 startlon : 0
 deltalat : -2.5
 deltalon : 2.5
 earth_radius : 6371.23
 .
 .
 .
Field #100
 name : 'HGT'
 description : 'Height'
 units : 'm'
 min/max value : 0 / 31173
 date : '2006-04-10_00:00:00'
 map source : 'unknown model from NCEP GRID 2'
 version : 5
 forecast hour : 0
 level : 1000
 ny x nx : 73 x 144
 projection : 0
 startlat : 90
 startlon : 0
 deltalat : -2.5
 deltalon : 2.5
 earth_radius : 6371.23

Example 2

This example shows how to use the three-step process of reading a WPS intermediate file using 1) wrf_wps_open_int, 2) wrf_wps_rdhead_int, and 3) wrf_wps_rddata_int.

 wps_filename = "NNRP:2006年04月10日_00"
;---Preallocate variables for header
 header = new(14,float)
 field = new(1,string)
 date = new(1,string)
 units = new(1,string)
 map_source = new(1,string)
 description = new(1,string)
 
 istatus = wrf_wps_open_int(wps_filename)
 if(istatus.ne.0) then
 print("Error opening " + wps_filename)
 exit
 end if
;---Continuously read data from WPS file until istatus != 0.
 nfields = 0
 do while (istatus.eq.0)
;---Read header
 wrf_wps_rdhead_int(istatus,header,field,date,units,\
 map_source,description)
 if(istatus.ne.0) then
 continue
 end if
 nx = toint(header(3))
 ny = toint(header(4))
;---Read data
 slab := wrf_wps_rddata_int(istatus,nx,ny)
 if(istatus.ne.0) then
 continue
 end if
;---Print information about each slab
 print("Field #" + (nfields+1))
 print(" name : '" + field + "'")
 print(" description : '" + description + "'")
 print(" units : '" + units + "'")
 print(" min/max value : " + min(slab) + " / " + max(slab))
 print(" date : '" + date + "'")
 print(" map source : '" + map_source + "'")
 print(" version : " + header(0))
 print(" forecast hour : " + header(1))
 print(" level : " + header(2))
 print(" ny x nx : " + header(4) + " x " + header(3))
 print(" projection : " + header(5))
 if(header(5).eq.0) then
 print(" startlat : " + header(6))
 print(" startlon : " + header(7))
 print(" deltalat : " + header(8))
 print(" deltalon : " + header(9))
 print(" earth_radius : " + header(10))
 else if(header(5).eq.1) then
 print(" startlat : " + header(6))
 print(" startlon : " + header(7))
 print(" dy x dx : " + header(9) + " x " + header(8))
 print(" truelat1 : " + header(10))
 print(" earth_radius : " + header(11))
 else if(header(5).eq.3) then
 print(" startlat : " + header(6))
 print(" startlon : " + header(7))
 print(" dy x dx : " + header(9) + " x " + header(8))
 print(" center lon : " + header(10))
 print(" truelat1 : " + header(11))
 print(" truelat2 : " + header(12))
 print(" earth_radius : " + header(13))
 else if(header(5).eq.4) then
 print(" startlat : " + header(6))
 print(" startlon : " + header(7))
 print(" nlats : " + header(8))
 print(" deltalon : " + header(9))
 print(" earth_radius : " + header(10))
 else if(header(5).eq.5) then
 print(" startlat : " + header(6))
 print(" startlon : " + header(7))
 print(" dy x dx : " + header(9) + " x " + header(8))
 print(" center lon : " + header(10))
 print(" truelat1 : " + header(11))
 print(" earth_radius : " + header(12))
 end if
 end if
 end if
 end if
 end if
 nfields = nfields + 1
 end do
 print("There were " + nfields + " fields in the " + wps_filename + " WPS file.")