Method: NumRu::Misc.check_shape_consistency

Defined in:
lib/numru/misc/misc.rb

.check_shape_consistency(cshapes, *args) ⇒ Object

Check the consistency of array shapes (multi-dim such as NArray).

Exception is raised if inconsistent.

ARGUMENTS
* cshapes (String) : description of the shapes of the args.
  Delimited by one-or-more spaces between arrays,
  and the shape of each array is delimited by a comma. The lengths are 
  expressed with string names as identifiers (in that case, length 
  values are unquestioned) or specified as positive integers.
  Use '..' or '...' for repetition of the last shape.
  See EXAMPLES below.

* args (multi-dim arrays such as NArray): arrays to be checked

RETURN VALUE
* nil

POSSIBLE EXCEPTIONS
* exception is raised if cshapes and args are inconsistent:

  * RuntimeError, if the arrays do not have shapes specified by cshapes.

  * ArgeumentError, if the number of args are inconsistent with cshapes. 
    This is likely a coding error of the user.

EXAMPLES

*  to check whether three arrays u, v, and w are shaped as
   u[nx], v[ny], and w[nx,ny], where nx and ny are any integer:

      NumRu::Misc.check_shape_consistency('nx ny nx,ny',u,v,w)

   Or equivalently,

      NumRu::Misc.check_shape_consistency('m  n  m,n',u,v,w)

   because actual strings does not matter.

* To specify fixed lengths, use integers instead of names:

      NumRu::Misc.check_shape_consistency('4  n  4,n',u,v,w)

  In this case, u,v,w must have shapes [4], [ny], and [4,ny],
  where ny is any length.

* Use '..' or '...' to repeat the same shape:

      NumRu::Misc.check_shape_consistency('nx,ny ...',u,v,w)

  This ensures that u, v, and w are 2D arrays with the same shape.
  Note: '..' and '...' are the same, so you can use whichever you like.



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# File 'lib/numru/misc/misc.rb', line 81

def check_shape_consistency(cshapes, *args)
	 ranks = Array.new
	 elm2idx = Hash.new
	 spl = cshapes.split(' ')
	 if spl.length >= 2 && /^\.\.\.?$/ =~ spl[-1]  # '..' or '...'
      ((spl.length-1)...args.length).each{|i|
  spl[i]=spl[i-1]
	    }	       
	 end
	 if spl.length != args.length
	    raise ArgumentError,"# of the argument (#{args.length}) is inconsistent with the 1st arg '#{cshapes}'"
	 end
   spl.each_with_index{|csh,i| 
	    sh = csh.split(',')
	    ranks.push( sh.length )
	    sh.each_with_index{|tag,j|
  elm2idx[tag] = Array.new if !elm2idx[tag]
  elm2idx[tag].push([i,j])
	    }
	 }
	 ranks.each_with_index{|len,i|
	    if args[i].rank != len
  raise "(#{i+1}th arg) unexepected rank #{args[i].rank} for #{len}"
	    end
	 }
	 elm2idx.each{|tag,ary|
	    if tag.to_i > 0   # numeric (positive integer)
  size = tag.to_i
  start = 0
	    else              # alphabet
  size = args[ary[0][0]].shape[ary[0][1]]
  start = 1
	    end
	    (start...ary.length).each{|i|
  if args[ary[i][0]].shape[ary[i][1]] != size
		  if start == 0
 raise "length of dim #{ary[i][1]} of #{ary[i][0]+1}th "+
                     "arg is unexpected " +
                     "(#{args[ary[i][0]].shape[ary[i][1]]} for #{size})"
		  else
 raise "Dimension lengths inconsistent between "+
			"dim #{ary[0][1]} of #{ary[0][0]+1}th arg and " +
    "dim #{ary[i][1]} of #{ary[i][0]+1}th arg"
		  end
  end
	    }
	 }
	 nil
end