section r of routines in std.i

functions in std.i - r

random


    random(dimension_list)  
    random_seed, seed  


returns an array of random double values with the given  
DIMENSION_LIST (nil for a scalar result), uniformly distributed  
on the interval from 0.0 to 1.0.  
The algorithm is from Press and Teukolsky, Computers in Physics,  
vol. 6, no. 5, Sep/Oct 1992 (ran2).  They offer a reward of $1000  
to anyone who can exhibit a statistical test that this random  
number generator fails in a "non-trivial" way.  
The random_seed call reinitializes the random number sequence;  
SEED should be between 0.0 and 1.0 non-inclusive; if SEED is  
omitted, nil, or out of range, the sequence is reinitialized as  
when Yorick starts.  
The numbers are actually at the centers of 2147483562 equal width  
bins on the interval [0,1].  Although only these 2 billion numbers  
are possible, the period of the generator is roughly 2.3e18.  
Builtin function, documented at i0/std.i   line 758

SEE ALSO: rdline

rdline


    rdline(f)  
 or rdline(f, n, prompt= pstring)  


returns next line from stream F (stdin if F nil).  If N is non-nil,  
returns a string array containing the next N lines of F.  If  
end-of-file occurs, rdline returns nil strings.  If F is nil,  
uses the PSTRING to prompt for input (default "read> ").  
Builtin function, documented at i0/std.i   line 2100

SEE ALSO: read, open, close, bookmark, backup, read_n, rdfile

re_part


    re_part(z)  


returns the real part of its argument.  (Same as double(z).)  
Unlike z.re, works if z is not complex.  
Keyword,  defined at i0/std.i   line 742

read


    n= read(f, format=fstring, obj1, obj2, ...)  
 or n= read(prompt= pstring, format=fstring, obj1, obj2, ...)  
 or n= sread(source, format=fstring, obj1, obj2, ...)  


   reads text from I/O stream F (1st form), or from the keyboard (2nd  
   form), or from the string or string array SOURCE (3rd form),  
   interprets it according to the optional FSTRING, and uses that  
   interpretation to assign values to OBJ1, OBJ2, ...  If the input  
   is taken from the keyboard, the optional prompt PSTRING (default  
   "read> ") is printed before each line is read.  The Yorick write  
   function does not interact with the read function -- writes are  
   always to end-of-file, and do not affect the sequence of lines  
   returned by read.  The backup (and bookmark) function is the  
   only way to change the sequence of lines returned by read.  
   There must be one non-supressed conversion specifier (see below)  
   in FSTRING for each OBJ to be read; the type of the conversion  
   specifier must generally match the type of the OBJ.  That is,  
   an integer OBJ requires an integer specifier (d, i, o, u, or x)  
   in FSTRING, a real OBJ requires a real specifier (e, f, or g),  
   and a string OBJ requires a string specifier (s or []).  An OBJ  
   may not be complex, a pointer, a structure instance, or any non-  
   array Yorick object.  If FSTRING is not supplied, or if it has  
   fewer conversion specifiers than the number of OBJ arguments,  
   then Yorick supplies default specifiers ("%ld" for integers,  
   "%lg" for reals, and "%s" for strings).  If FSTRING contains more  
   specifiers than there are OBJ arguments, the part of FSTRING  
   beginning with the first specifier with no OBJ is ignored.  
   The OBJ may be scalar or arrays, but the dimensions of every OBJ  
   must be identical.  If the OBJ are arrays, Yorick behaves as  
   if the read were called in a loop numberof(OBJ1) times, filling  
   one array element of each of the OBJ according to FSTRING on  
   each pass through the loop.  (Note that this behavior includes  
   the case of reading columns of numbers by a single call to read.)  
   The return value N is the total number of scalar assignments  
   which were made as a result of this call.  (If there were 4  
   OBJ arguments, and each was an array with 17 elements, a return  
   value of N==35 would mean the following:  The first 8 elements  
   of OBJ1, OBJ2, OBJ3, and OBJ4 were read, and the 9th element of  
   OBJ1, OBJ2, and OBJ3 was read.)  The read function sets any  
   elements of the OBJ which were not read to zero -- hence,  
   independent of the returned N, the all of the old data in the  
   OBJ arguments is overwritten.  
   The read or sread functions continue reading until either:  
   (1) all elements of all OBJ have been filled, or (2) end-of-file  
   (or end of SOURCE for sread) is reached ("input failure"), or  
   (3) part of FSTRING or a conversion specifier supplied by  
   default fails to match the source text ("matching failure").  
   The FSTRING is composed of a series of "directives" which are  
   (1) whitespace -- means to skip any amount of whitespace in the  
       source text  
   (2) characters other than whitespace and % -- must match the  
       characters in the source text exactly, or matching failure  
       occurs and the read operation stops  
   (3) conversion specifiers beginning with % and ending with a  
       character specifying the type of conversion -- optionally  
       skip whitespace, then convert as many characters as  
       continue to "look like" the conversion type, possibly  
       producing a matching failure  
   The conversion specifier is of the form %*WSC, where:  
is either the character '*' or not present  
     A specifier beginning with %* does not correspond to any of  
     the OBJ; the converted value will be discarded.  
   W is either a positive decimal integer specifying the maximum  
     field width (not including any skipped leading whitespace),  
     or not present if any number of characters up to end-of-line  
     is acceptable.  
   S is either one of the characters 'h', 'l', or 'L', or not  
     present.  Yorick allows this for compatibility with the C  
     library functions, but ignores it.  
   C is a character specifying the type of conversion:  
     d   - decimal integer  
     i   - decimal, octal (leading 0), or hex (leading 0x) integer  
     o   - octal integer  
     u   - unsigned decimal integer (same as d for Yorick)  
     x, X            - hex integer  
     e, f, g, E, G   - floating point real  
     s   - string of non-whitespace characters  
     [xxx]   - (xxx is any sequence of characters) longest string  
               of characters matching those in the list  
     [^xxx]  - longest string of characters NOT matching those in  
               the list (this is how you can extend %s to be  
               delimited by something other than whitespace)  
     %   - the ordinary % character; complete conversion  
           specification must be "%%"  
   The read function is modeled on the ANSI standard C library  
   fscanf and sscanf functions, but differs in several respects:  
     (1) Yorick's read cannot handle the %c, %p, or %n conversion  
         specifiers in FSTRING.  
     (2) Yorick's read never results in a portion of a line  
         being read -- any unused part of a line is simply discarded  
         (end FSTRING with "%[^\n]" if you want to save the trailing  
         part of an input line).  
     (3) As a side effect of (2), there are some differences between  
         fscanf and Yorick's read in how whitespace extending across  
         newlines is handled.  
   Builtin function, documented at i0/std.i   line 1994

SEE ALSO: rdline, write, open, close, bookmark, backup, save, restore, read_n

read_clog


    file= read_clog(file, clog_name)  


raw routine to set the binary data structure of FILE according  
to the text description in the Contents Log file CLOG_NAME.  
Builtin function, documented at i0/std.i   line 2649

read_n


    read_n, f, n0, n1, n2, ...  


grabs the next numbers N0, N1, N2, ... from file F, skipping over  
any whitespace, comma, semicolon, or colon delimited tokens which  
are not numbers.  (Actually, only the first and last characters of  
the token have to look like a number -- 4xxx3 would be read as 4.)  
***WARNING*** at most ten Ns are allowed  
The Ns can be arrays, provided all have the same dimensions.  
Keyword,  defined at i0/std.i   line 2133