all functions - j



     Interpreted function, defined at i/demo4.i   line 79  



    jc, file, ncyc  

jump to the record of FILE nearest the specified NCYC.  
Interpreted function, defined at i0/std.i   line 3143  

SEE ALSO: jt,   _jc,   edit_times,   show,   jr  


    image = jpeg_read(filename)  
 or image = jpeg_read(filename, comments)  
 or shape = jpeg_read(filename, comments, [0,0,0,0])  
 or image = jpeg_read(filename, comments, subset)  

Read jpeg file FILENAME.  The returned IMAGE is 3-by-width-by-height  
for rgb images (the usual case) or just width-by-height for grayscale  
images.  Note that the scanline order is top-to-bottom.  
If COMMENTS is present, it must be a simple variable reference.  
That variable will be set to either nil or a string array containing  
all the descriptive comments in the file.  
In the third form, the return value is [nchan,width,height] instead  
of the image, where nchan=1 or nchan=3.  
In the fourth form, SUBSET is [i0,i1,j0,j1] and the returned image is  
the subset full_image(..,i0:i1,j0:j1) of the full image.  (This is  
inefficient, but, for example, some Mars Rover pictures released by  
NASA are inconveniently large.)  
   Builtin function, documented at i0/jpeg.i   line 9  

SEE ALSO: jpeg_write  


    jpeg_write, filename, image  
 or jpeg_write, filename, image, comments, quality  

Write jpeg file FILENAME containing IMAGE at the specified QUALITY.  
The default QUALITY is 75; the range is from 0 to 100.  The IMAGE  
can be either 3-by-width-by-height for rgb or width-by-height for  
grayscale.  Note that scanline order is top-to-bottom.  
If COMMENTS is non-nil, it is a string or an array of strings that  
will be written as descriptive comments in the jpeg file.  
   Builtin function, documented at i0/jpeg.i   line 32  

SEE ALSO: jpeg_read  


    jr, file, i  
 or _jr(file, i)  

Jump to a particular record number I (from 1 to n_records) in a  
binary file FILE.  The function returns 1 if such a record exists,  
0 if there is no such record.  In the latter case, no action is  
taken; the program halts with an error only if jr was invoked  
as a subroutine.  Record numbering wraps like array indices; use  
jr, file, 0  to jump to the last record, -1 to next to last, etc.  
Interpreted function, defined at i0/std.i   line 3166  

SEE ALSO: jt,   jc,   edit_times,   show  


    jt, time  
 or jt, file, time  
 or jt, file  
 or jt, file, -  

  jump to the record nearest the specified TIME.  If no FILE is  
  specified, the current record of all open binary files containing  
  records is shifted.  
  If both FILE and TIME are specified and jt is called as a function,  
  it returns the actual time of the new current record.  
N.B.: "jt, file" and "jt, file, -" are obsolete.  Use the jr function to  
  step through a file one record at a time.  
  If only the FILE is specified, increment the current record of that  
  FILE by one.  If the TIME argument is - (the pseudo-index range  
  function), decrement the current record of FILE by one.  
  If the current record is the last, "jt, file" unsets the current record  
  so that record variables will be inaccessible until another jt or jc.  
  The same thing happens with "jt, file, -" if the current record was the  
  If only FILE is specified, jt returns 1 if there is a new current  
  record, 0 if the call resulted in no current record.  Thus "jt(file)"  
  and "jt(file,-)" may be used as the condition in a while loop to step  
  through every record in a file:  
     file= openb("example.pdb");  
     do {  
       restore, file, interesting_record_variables;  
     } while (jt(file));  
  Interpreted function, defined at i0/std.i   line 3106  

SEE ALSO: jc,   _jt,   edit_times,   show,   jr