1 /*
2 * $Id: prefix.i,v 1.1 2005-09-18 22:06:04 dhmunro Exp $
3 * Functions to read and write arrays of real numbers tagged by
4 * a prefix at the beginning of each line.
5 */
6 /* Copyright (c) 2005, The Regents of the University of California.
7 * All rights reserved.
8 * This file is part of yorick (http://yorick.sourceforge.net).
9 * Read the accompanying LICENSE file for details.
10 */
11
12 func prefix_find(f, prefix, delimit=)
13 /* DOCUMENT prefix_find(f, prefix)
14 scan to the first line of text file F which begins with the
15 blank delimited prefix PREFIX. (You may specify other delimiters
16 by giving prefix_find a DELIMIT keyword, whose value will be
17 passed to the strtok function.) The return value is 1 if such
18 a line was found, 0 if not. In the first case, F will be positioned
19 to reread the prefixed line; in the second case, F will be at the
20 end-of-file.
21
22 SEE ALSO: prefix_read, prefix_write, strtok
23 */
24 {
25 if (is_void(delimit)) delimit= " \t\n";
26 found= 0;
27 while (line= rdline(f)) {
28 if (strtok(line,delimit)(1)==prefix) {
29 found= 1;
30 backup, f;
31 break;
32 }
33 }
34 return found;
35 }
36
37 func prefix_read(f, prefix, delimit=, comment=)
38 /* DOCUMENT value_array= prefix_read(f, prefix)
39 reads lines of text file F which begin with the blank delimited
40 prefix PREFIX. (You may specify other delimiters by giving
41 prefix_read a DELIMIT keyword, whose value will be passed to the
42 strtok function.) Stops when a line not beginning with that
43 prefix is encountered. You may also supply a COMMENT keyword,
44 which should be a function accepting a string argument and
45 returning 0 to indicate that the line is not a comment line,
46 and 1 to indicate that it is a comment. By default, blank lines
47 and lines beginning with "#" are taken as comments and skipped.
48
49 The returned VALUE_ARRAY is [] if no PREFIX lines were found,
50 and an array of type double and length equal to the total number
51 of numbers Ni:
52
53 prefix N1 N2 N3 N4
54 prefix N5 N6
55 prefix ... Nn
56
57 SEE ALSO: prefix_find, prefix_write, prefix_comment, strtok
58 */
59 {
60 if (is_void(delimit)) delimit= " \t\n";
61 if (is_void(comment)) comment= prefix_comment;
62 n= l= 0;
63 values= array(pointer, 100);
64 target= array(0.0, 256); /* max number of values per line */
65 while (line= rdline(f)) {
66 tok= strtok(line,delimit);
67 if (tok(1)==prefix) {
68 nn= sread(prefix_unD(tok(2)), target);
69 if (nn>0) {
70 n+= nn;
71 if (l==numberof(values)) grow, values, array(pointer, 100);
72 values(++l)= &target(1:nn);
73 }
74 } else if (!comment(line)) {
75 backup, f;
76 break;
77 }
78 }
79 if (!n) return [];
80 result= array(0.0, n);
81 n= 0;
82 for (i=1 ; i<=l ; i++) {
83 target= *values(i);
84 nn= n+numberof(target);
85 result(n+1:nn)= target;
86 n= nn;
87 }
88 return result;
89 }
90
prefix_comment(line)91 func prefix_comment(line)
92 /* DOCUMENT prefix_comment(line)
93 the default comment detector function for prefix_read, makes
94 blank lines and any line beginning with "#" as its first non-blank
95 character a comment.
96 */
97 {
98 tok= strtok(line)(1);
99 return (strlen(tok)<1 || strpart(tok,1:1)=="#");
100 }
101
prefix_unD(text)102 func prefix_unD(text)
103 {
104 if (text) {
105 c= *pointer(text);
106 d= where(c=='D' | c=='d');
107 if (numberof(d)) {
108 c(d)= 'e';
109 text= string(&c);
110 }
111 }
112 return text;
113 }
114
115 func prefix_write(f, prefix, values, ndigits=, width=)
116 /* DOCUMENT prefix_read, f, prefix, value_array
117 writes lines of text file F which begin with the prefix PREFIX:
118
119 prefix N1 N2 N3 N4 N5
120 prefix N6 N7 N8 N9 N10
121 prefix N11 N12
122
123 The format is %14.6e by default, but you can adjust the ".6" by
124 specifying an NDIGITS keyword (6 is the default).
125
126 Yorick will put as many numbers as fit within 79 characters by
127 default, and each successive line begins with PREFIX. You can
128 change this default line width by specifying a WIDTH keyword
129 (default 79).
130
131 SEE ALSO: prefix_find, prefix_read
132 */
133 {
134 if (is_void(width)) width= 79;
135 if (is_void(ndigits)) ndigits= 6;
136 else if (ndigits>24) ndigits= 24;
137 else if (ndigits<0) ndigits= 0;
138 ntot= 8+ndigits;
139 format= swrite(format="%%%ld.%lde",ntot,ndigits);
140 l= (width-strlen(prefix))/ntot;
141 if (l<1) l= 1;
142 n= numberof(values);
143 nlines= n/l;
144 j= n%l;
145 text= array(prefix, (j? nlines+1 : nlines));
146 for (i=1 ; i<=l ; i++) {
147 /* format the text one column at a time --
148 some columns may be one shorter than others */
149 if (i>n) break;
150 column= swrite(format=format, values(i:0:l));
151 if (j && i>j) text(1:nlines)+= column;
152 else text+= column;
153 }
154 write, f, format="%s\n", text;
155 }
156