|
1 ;---------------------------------------------------------------------- |
|
2 ; This example reads an ASCII file that is formatted a specific way, and |
|
3 ; writes out the results to a netCDF file. |
|
4 ; |
|
5 ; The first line in the ASCII file must be a header, with each field |
|
6 ; separated by a single character delimiter (like a ","). The rest of |
|
7 ; the file must be such that each row contains all fields, each |
|
8 ; separated by the designated delimiter. |
|
9 ; |
|
10 ; The fields can be integer, float, double, or string. |
|
11 ;---------------------------------------------------------------------- |
|
12 |
|
13 ;---------------------------------------------------------------------- |
|
14 ; This function returns the index locations of the given delimiter |
|
15 ; in a row or several rows of strings. |
|
16 ;---------------------------------------------------------------------- |
|
17 function delim_indices(strings,nfields,delimiter) |
|
18 local cstrings, cdelim |
|
19 begin |
|
20 nrows = dimsizes(strings) |
|
21 ; |
|
22 ; Handle special case if we only have one string. Make sure it |
|
23 ; is put into a 2D array. |
|
24 ; |
|
25 if(nrows.eq.1) then |
|
26 cstrings = new((/1,strlen(strings)+1/),character) |
|
27 end if |
|
28 |
|
29 cstrings = stringtochar(strings) ; Convert to characters. |
|
30 cdelim = stringtochar(delimiter) ; Convert delimiter to character. |
|
31 ; |
|
32 ; Som error checking here. Make sure delimiter is one character. |
|
33 ; |
|
34 nc = dimsizes(cdelim) |
|
35 rank = dimsizes(nc) |
|
36 if(rank.ne.1.or.(rank.eq.1.and.nc.ne.2)) then |
|
37 print("delim_indices: fatal: the delimiter you've selected") |
|
38 print("must be a single character. Can't continue.") |
|
39 exit |
|
40 end if |
|
41 |
|
42 ; |
|
43 ; Create array to hold indices of delimiter locations, and then loop |
|
44 ; through each row and find all the delimiters. Make sure each row has |
|
45 ; the correct number of delimiters. |
|
46 ; |
|
47 ndelims = nfields-1 |
|
48 cindices = new((/nrows,ndelims/),integer) |
|
49 do i = 0, nrows-1 |
|
50 ii = ind(cstrings(i,:).eq.cdelim(0)) |
|
51 ; |
|
52 ; Make sure there were delimiters on this row. If not, we just quit. |
|
53 ; This could probably be modified to do this more gracefully. |
|
54 ; |
|
55 if(any(ismissing(ii))) then |
|
56 print("delim_indices: fatal: I didn't find any delimiters") |
|
57 print("('" + delimiter + "') on row " + i + ". Can't continue.") |
|
58 exit |
|
59 end if |
|
60 if(dimsizes(ii).ne.ndelims) then |
|
61 print("delim_indices: fatal: I expected to find " + ndelims) |
|
62 print("delimiters on row " + i + ". Instead, I found " + dimsizes(ii) + ".") |
|
63 print("Can't continue.") |
|
64 exit |
|
65 end if |
|
66 |
|
67 cindices(i,:) = ii |
|
68 |
|
69 delete(ii) ; For next time through loop |
|
70 end do |
|
71 |
|
72 return(cindices) |
|
73 end |
|
74 |
|
75 ;---------------------------------------------------------------------- |
|
76 ; This function reads in a particular field from a string array, |
|
77 ; given the field number to read (fields start at 1 and go to nfield), |
|
78 ; and the indices of the delimiters. |
|
79 ; |
|
80 ; It returns either an integer, float, double, or a string, |
|
81 ; depending on the input flag "return_type". |
|
82 ;---------------------------------------------------------------------- |
|
83 function read_field(strings,ifield,indices,return_type) |
|
84 local nstring, cstrings, nf, tmp_str |
|
85 begin |
|
86 nrows = dimsizes(strings) |
|
87 ; |
|
88 ; Handle special case if we only have one string. Make sure it |
|
89 ; is put into a 2D array. |
|
90 ; |
|
91 if(nrows.eq.1) then |
|
92 cstrings = new((/1,strlen(strings)+1/),character) |
|
93 end if |
|
94 |
|
95 cstrings = stringtochar(strings) |
|
96 nf = dimsizes(indices(0,:))+1 ; indices is nrows x (nfields-1) |
|
97 |
|
98 ; |
|
99 ; Error checking. Make sure user has entered a valid field. |
|
100 ; |
|
101 if(ifield.le.0.or.ifield.gt.nf) then |
|
102 print("read_field: fatal: you've selected a field that is") |
|
103 print("out-of-range of the number of fields that you have (" + nf + ").") |
|
104 exit |
|
105 end if |
|
106 |
|
107 ; |
|
108 ; Set up array to return. |
|
109 ; |
|
110 return_array = new(nrows,return_type) |
|
111 |
|
112 do i = 0,nrows-1 |
|
113 ; |
|
114 ; Special case of first field in row. |
|
115 ; |
|
116 if(ifield.eq.1) then |
|
117 ibeg = 0 |
|
118 iend = indices(i,ifield-1)-1 |
|
119 else |
|
120 ; |
|
121 ; Special case of first field in row. |
|
122 ; |
|
123 if(ifield.eq.nf) then |
|
124 ibeg = indices(i,ifield-2)+1 |
|
125 iend = dimsizes(cstrings(i,:))-1 |
|
126 ; |
|
127 ; Any field between first and last field. |
|
128 ; |
|
129 else |
|
130 ibeg = indices(i,ifield-2)+1 |
|
131 iend = indices(i,ifield-1)-1 |
|
132 end if |
|
133 end if |
|
134 ; |
|
135 ; Here's the code that pulls off the correct string, and converts it |
|
136 ; to float if desired. |
|
137 ; |
|
138 if(return_type.eq."integer") then |
|
139 return_array(i) = stringtointeger(chartostring(cstrings(i,ibeg:iend))) |
|
140 end if |
|
141 if(return_type.eq."float") then |
|
142 return_array(i) = stringtofloat(chartostring(cstrings(i,ibeg:iend))) |
|
143 end if |
|
144 if(return_type.eq."double") then |
|
145 return_array(i) = stringtodouble(chartostring(cstrings(i,ibeg:iend))) |
|
146 end if |
|
147 if(return_type.eq."string") then |
|
148 return_array(i) = chartostring(cstrings(i,ibeg:iend)) |
|
149 end if |
|
150 end do |
|
151 |
|
152 return(return_array) |
|
153 end |
|
154 |
|
155 ;---------------------------------------------------------------------- |
|
156 ; Main code. |
|
157 ;---------------------------------------------------------------------- |
|
158 begin |
|
159 ; |
|
160 ; Set up defaults here. We have to hard-code the field types, |
|
161 ; because we can't really tell otherwise. |
|
162 |
|
163 filename = "data.81" ; ASCII" file to read. |
|
164 cdf_file = filename + ".nc" ; netCDF file to write. |
|
165 nfields = 22 ; # of fields |
|
166 delimiter = "," ; field delimiter |
|
167 ; |
|
168 ; In this case, fields #6-#8 are strings, fields #2, #3, and #11 |
|
169 ; are float, and the rest of the fields are integers. |
|
170 ; |
|
171 var_types = new(nfields,string) |
|
172 var_types = "integer" ; Most are ints. |
|
173 var_types(5:7) = "string" ; corresponds to fields 6-8 |
|
174 var_types(1:2) = "float" |
|
175 var_types(10) = "float" |
|
176 |
|
177 if(isfilepresent(cdf_file)) |
|
178 print("Warning: '" + cdf_file + "' exists. Will remove it.") |
|
179 system("/bin/rm " + cdf_file) |
|
180 end if |
|
181 |
|
182 ; |
|
183 ; Read in data as strings. This will create a string array that has the |
|
184 ; same number of strings as there are rows in the file. We will then need |
|
185 ; to parse each string later. |
|
186 ; |
|
187 read_data = asciiread(filename,-1,"string") |
|
188 header = read_data(0) ; Header. Use for variable names. |
|
189 data = read_data(1:) ; Get rid of first line which is a header. |
|
190 nrows = dimsizes(data) ; Number of rows. |
|
191 |
|
192 ; |
|
193 ; Read in locations of delimiters in each string row. |
|
194 ; |
|
195 hindices = delim_indices(header,nfields,delimiter) ; header row |
|
196 dindices = delim_indices(data,nfields,delimiter) ; rest of file |
|
197 |
|
198 ; |
|
199 ; Read in the field names which will become variable names on |
|
200 ; the netCDF file. |
|
201 ; |
|
202 var_names = new(nfields,string) |
|
203 |
|
204 do i=0,nfields-1 |
|
205 var_names(i) = read_field(header,i+1,hindices,"string") |
|
206 end do |
|
207 ; |
|
208 ; Write out this netCDF file efficiently so it will be faster. |
|
209 ; Try to predefine everything before you write to it. |
|
210 ; |
|
211 f = addfile(cdf_file,"c") |
|
212 setfileoption(f,"DefineMode",True) ; Enter predefine phase. |
|
213 |
|
214 ; |
|
215 ; Write global attributes to file. It's okay to do this before |
|
216 ; predefining the file's variables. We are still in "define" mode. |
|
217 ; |
|
218 fAtt = True |
|
219 fAtt@description = "Data read in from '" + filename + "' ASCII file." |
|
220 fAtt@creation_date = systemfunc ("date") |
|
221 fileattdef( f, fAtt ) |
|
222 |
|
223 ; |
|
224 ; Write dimension name. There's only one here. |
|
225 ; |
|
226 filedimdef(f,"nvalues",-1,True) |
|
227 |
|
228 ; |
|
229 ; Define each variable on the file, giving it the dimension name |
|
230 ; we just created above. |
|
231 ; |
|
232 ; Don't deal with variables that are of type string. |
|
233 ; |
|
234 do i=0,nfields-1 |
|
235 if(var_types(i).ne."string") then |
|
236 filevardef(f, var_names(i), var_types(i), "nvalues") |
|
237 end if |
|
238 end do |
|
239 |
|
240 ; |
|
241 ; Loop through each field, read the values for that field, print |
|
242 ; information about the variable, and then write it to the netCDF |
|
243 ; file. |
|
244 ; |
|
245 do i=0,nfields-1 |
|
246 ifield = i+1 ; Fields start at #1, not #0. |
|
247 ; |
|
248 ; You can't write strings to a netCDF file, so skip the string fields. |
|
249 ; |
|
250 if(var_types(i).ne."string") then |
|
251 tmp_data = read_field(data,ifield,dindices,var_types(i)) |
|
252 ; |
|
253 ; Print some info about the variable. |
|
254 ; |
|
255 print("") |
|
256 print("Writing variable " + var_names(i) + " (field #" + ifield + ").") |
|
257 print("Type is " + var_types(i) + ", min/max = " + min(tmp_data) + \ |
|
258 "/" + max(tmp_data)) |
|
259 |
|
260 if(any(ismissing(tmp_data))) then |
|
261 print("This variable does contain missing values.") |
|
262 else |
|
263 print("This variable doesn't contain missing values.") |
|
264 end if |
|
265 |
|
266 f->$var_names(i)$ = tmp_data ; Write to netCDF file. |
|
267 |
|
268 delete(tmp_data) ; Delete for next round. |
|
269 end if |
|
270 end do |
|
271 end |