;+ ; Type: function. ; Purpose: Read Polar Hydra data for a time range. ; Source: ftp://cdaweb.gsfc.nasa.gov/pub/data/polar/hydra. ; Parameters: ; tr0, in, double/string, req. Set the time. ; For double, it's the unix time or UTC. For string, it's the ; formatted string accepted by stoepoch, e.g., 'YYYY-MM-DD/hh:mm'. ; Keywords: ; filename, in, string or strarr[n], optional. The full file name(s) includes ; explicit paths. ; locroot, in, string, optional. The local data root directory. ; remroot, in, string, optional. the remote data root directory. ; type, in, string, optional. Data type. Supported type h0 and k0. ; Default is h0. ; version, in, string, optional. Data version. In case to load an old ; version data. By default, the highest version is loaded. ; vars, in, strarr[n], optional. Set the variables to be loaded. There are ; default settings for each type of data, check skeleton file to find ; the available variables. ; newnames, in/out, strarr[n], optional. The variable names appeared in the ; returned structure. Must be valid names for structure tags. ; Return: struct. ; Notes: none. ; Dependence: slib. ; History: ; 2013-06-17, Sheng Tian, create. ;- function sread_polar_hydra, tr0, filename = fn0, $ vars = var0s, newnames = var1s, $ locroot=locroot, remroot=remroot, type=type, version=version, _extra=ex compile_opt idl2 ; local and remote directory. if n_elements(locroot) eq 0 then locroot = spreproot('polar/hydra') if n_elements(remroot) eq 0 then $ remroot = 'ftp://cdaweb.gsfc.nasa.gov/pub/data/polar/hydra' ; **** prepare file names. utr0 = tr0 if n_elements(type) eq 0 then type = 'h0' ; can be k0 or h0. vsn = (n_elements(version))? version: 'v[0-9]{2}' ext = 'cdf' baseptn = 'po_'+type+'_hyd_yyyyMMdd_'+vsn+'.'+ext rempaths = [remroot,'hyd_'+type,'YYYY',baseptn] if type eq 'k0' then rempaths = [remroot,'hydra_'+type,'YYYY',baseptn] locpaths = [locroot,'hyd_'+type,'YYYY',baseptn] remfns = sprepfile(utr0, paths = rempaths) locfns = sprepfile(utr0, paths = locpaths) nfn = n_elements(locfns) locidx = 'SHA1SUM' for i = 0, nfn-1 do begin basefn = file_basename(locfns[i]) locpath = file_dirname(locfns[i]) rempath = file_dirname(remfns[i]) locfns[i] = sgetfile(basefn, locpath, rempath, locidx = locidx, _extra=ex) endfor idx = where(locfns ne '', nfn) if nfn ne 0 then locfns = locfns[idx] else return, -1 ; **** check record index. locfns, nfn, recs, and etrs. epvname = (type eq 'h0')? 'EPOCH': 'Epoch' if n_elements(tr0) eq 0 then begin ; no time info. recs = lon64arr(nfn,2)-1 ; [-1,-1] means to read all records. etrs = dblarr(2) tmp = scdfread(locfns[0],epvname,0) ets = *(tmp[0].value) & ptr_free, tmp[0].value etrs[0] = ets[0] tmp = scdfread(locfns[nfn-1],epvname,-1) ets = *(tmp[0].value) & ptr_free, tmp[0].value etrs[1] = ets[0] endif else begin ; there are time info. if size(tr0,/type) eq 7 then tformat = '' else tformat = 'unix' etrs = stoepoch(tr0, tformat) flags = bytarr(nfn) ; 0 for no record. recs = lon64arr(nfn,2) for i = 0, nfn-1 do begin tmp = scdfread(locfns[i],epvname) ; read each file's epoch. ets = *(tmp[0].value) & ptr_free, tmp[0].value if n_elements(etrs) eq 1 then begin ; tr0 is time. tmp = min(ets-etrs,idx, /absolute) dr = sdatarate(ets) if abs(ets[idx]-etrs) gt dr then flags[i] = 0 else begin flags[i] = 1b recs[i,*] = [idx,idx] endelse endif else begin ; tr0 is time range. idx = where(ets ge etrs[0] and ets le etrs[1], cnt) if cnt eq 0 then flags[i] = 0 else begin flags[i] = 1b recs[i,*] = [idx[0],idx[cnt-1]] endelse endelse endfor idx = where(flags eq 1b, cnt) if cnt eq 0 then begin message, 'no data at given time ...', /continue return, -1 endif else begin locfns = locfns[idx] recs = recs[idx,*] endelse endelse nfn = n_elements(locfns) ; **** prepare var names. if n_elements(var0s) eq 0 then begin case type of 'h0': begin var0s = ['EPOCH','ELECTRON_DIFFERENTIAL_ENERGY_FLUX',$ 'ION_DIFFERENTIAL_ENERGY_FLUX','ENERGY_ELE','ENERGY_ION'] if n_elements(var1s) eq 0 then $ var1s = ['epoch','jee','jei','ene','eni'] & end 'k0': begin var0s = ['Epoch','ELE_DENSITY','ELE_MEAN_ENERGY'] if n_elements(var1s) eq 0 then $ var1s = ['epoch','nele','enele'] & end else: message, 'unknown data type ...' endcase endif if n_elements(var1s) eq 0 then var1s = idl_validname(var0s) var1s = idl_validname(var1s) ; **** module for variable loading. nvar = n_elements(var0s) if nvar ne n_elements(var1s) then message, 'mismatch var names ...' ptrs = ptrarr(nvar) ; first file. tmp = scdfread(locfns[0],var0s,recs[0,*]) for j = 0, nvar-1 do ptrs[j] = (tmp[j].value) ; rest files. for i = 1, nfn-1 do begin tmp = scdfread(locfns[i],var0s,recs[i,*]) for j = 0, nvar-1 do begin ; works for all dims b/c cdf records on the 1st dim of array. *ptrs[j] = [*ptrs[j],*(tmp[j].value)] ptr_free, tmp[j].value ; release pointers. endfor endfor ; remove fill value. fillval = -1e31 vars = ['ELECTRON_DIFFERENTIAL_ENERGY_FLUX','ION_DIFFERENTIAL_ENERGY_FLUX'] for i = 0, n_elements(vars)-1 do begin idx = where(var0s eq vars[i], cnt) & idx = idx[0] if cnt eq 0 then continue idx2 = where(*ptrs[idx] eq fillval, cnt) if cnt ne 0 then (*ptrs[idx])[idx2] = !values.d_nan endfor ; move data to structure. dat = create_struct(var1s[0],*ptrs[0]) for j = 1, nvar-1 do dat = create_struct(dat, var1s[j],*ptrs[j]) for j = 0, nvar-1 do ptr_free, ptrs[j] return, dat end hydr = sread_polar_hydra(filename = $ ['L:\data\polar\hydra\hyd_h0\1998\po_h0_hyd_19980323_v01.cdf']) ;hydr = sread_polar_hydra('1998-03-23') ;hydr = sread_polar_hydra('2004-11-07', type = 'k0') ;hydr = sread_polar_hydra([et1, et2]). end