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wrf_wps_rddata_int
Reads a 2D field from an open WPS intermediate file.
Available in version 6.3.0 and later.
Prototype
function wrf_wps_rddata_int ( istatus [1] : integer, nx [1] : integer, ny [1] : integer ) return_val [ny][nx] : float
Description
This function reads the 2D data field for the current field of an open WPS intermediate file. It is meant to be used as part of a 3-step process for reading data off a WPS intermediate file:
- 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
Steps #2 and #3 are meant to be called continuously in an NCL "do while" loop. The istatus variable will be set to 0 by this procedure to indicate the data was read successfully, and that you can now attempt to read another field using wrf_wps_rdhead_int. If istatus is not equal to 0, then no more fields can be read off the file.
To read a WPS file with a single function call, see wrf_wps_read_int. The examples below illustrate both methods for reading a WPS file.
See Also
wrf_wps_open_int, wrf_wps_rdhead_int, wrf_wps_rddata_int, wrf_wps_read_int, wrf_wps_write_int, wrf_wps_close_int
Examples
Example 1
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.
See example 2 below for a script that uses wrf_wps_read_int to read the file in one step.
wps_filename = "NNRP:2006-04-10_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.")
Output: (run with "-n" option to remove annoying "(0)")
Field #1 name : 'PMSL' description : 'Sea-level Pressure' units : 'Pa' min/max value : 95120 / 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 : 29479 / 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 There were 100 fields in the NNRP:2006-04-10_00 WPS file.
Example 2
This example shows how to use wrf_wps_read_int to read a WPS intermediate file in one step.
wps_filename = "NNRP:2006-04-10_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:2006-04-10_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