From LJM@SLACVM.BITNET Fri Jul 22 10:27:00 1994 Received: from vm.uni-c.dk by dkuug.dk with SMTP id AA25862 (5.65c8/IDA-1.4.4j for ); Sat, 23 Jul 1994 03:30:05 +0200 Message-Id: <199407230130.AA25862@dkuug.dk> Received: from vm.uni-c.dk by vm.uni-c.dk (IBM VM SMTP V2R2) with BSMTP id 1809; Sat, 23 Jul 94 03:30:48 DNT Received: from SLACVM.SLAC.STANFORD.EDU by vm.uni-c.dk (Mailer R2.07) with BSMTP id 1411; Sat, 23 Jul 94 03:30:47 DNT Received: by SLACVM (Mailer R2.08 R208004) id 5758; Fri, 22 Jul 94 18:28:32 PST Date: Fri, 22 Jul 1994 18:27 -0800 (PST) From: "Len Moss" To: "SC22/WG5 Mailing List" Subject: Updates to the JOR X-Charset: ASCII X-Char-Esc: 29 Five new items have just been registered in X3J3's Journal Of Requirements (JOR). I have just ftp'ed them to the /incoming directory on Kurt's server, and they should appear soon in the /x3j3 directory as: 94-004r4.Z /* The full version */ 94-004r4s.Z /* The subset version */ Because of the short time until the August meetings, I am including the complete text of the new items below. Please note that all the items refer to supporting material in the file /x3j3/mullen.ps on Kurt's server. I sent this file to Kurt, but he may wish to rename it or place it elsewhere, so you might have to poke around a little to find it. As the suffix implies, it contains PostScript. ---------------------------------------------------------------------- 069 Intrinsic function CONCAT <KEYWORDS> INTRINSIC FUNCTION CONCAT CONCATENATION ARRAY <STATUS> Registered <TARGET> <SUBGROUP> /JOR <VERSION> 1 <REQUIREMENT> Addition of an intrinsic function that concatenates the elements of an array. <JUSTIFICATION> In a two dimensional array, concatenation of the first dimension complemented with reshape provides the initial operation for a monolithic operation to join arrays but may be insufficient in general when concatenation is desired over the last dimension. For two dimensional array this can be achieved by transposing each array, concatenating over the first dimension then transposing but it is cumbersome and not obvious. Furthermore for consistency, all monolithic array operations should be generalized and defined over all dimensions supported by the language. <SUGGESTED IMPLEMENTATION> Define the intrinsic function CONCAT(A,B,DIM) where A and B are arrays and DIM is the dimension to concatenate over. DIM is optional and defaults to the first dimension. For example give the following fragment: A=RESHAPE((/ 0, 1, 2, 3 /),(/ 2, 2 /)) B=CONCAT(A,A) C=CONCAT(A,A,2) The result in B would be AE 0 1 AA AE 2 3 AA AE 0 1 AA AE 2 3 AA and C would be AE 0 1 0 1 AA AE 2 3 2 3 AA AEDetailed edits available in /x3j3/mullin.ps at ftp.ncsa.uiuc.edu.AA </SUGGESTED IMPLEMENTATION> <ESTIMATED IMPACT> This affects only new programs. It will not invalidate any existing programs. <SUBMITTED BY> Lenore R. Mullin, Scott Thibault, and Nicole Nemer Phone: 314-341-4492 Email: lenore@cs.umr.edu, sthib@cs.umr.edu, nnemer@cs.umr.edu </SUBMITTED BY> <HISTORY> <EVENT> Jul 94: Proposal submitted via email. </HISTORY> </FORTREQ> ---------------------------------------------------------------------- <FORTREQ> <NUMBER> 070 <TITLE> Extended indexing capabilities <KEYWORDS> INDEXING SECTIONS ARRAY EXPRESSION <STATUS> Registered <TARGET> <SUBGROUP> /parallel <VERSION> 1 <REQUIREMENT> The ability to index an array expression by subscripts or by sections. <JUSTIFICATION> Although a programmer can describe the desired indexing of an array expression over a number of lines, once monolithic arrays are added to the language it is more intuitive to describe what indices are desired after a number of operations are applied to one or more arrays in their entirety. <SUGGESTED IMPLEMENTATION> Extend grammar rule R701 to include the alternative "(" Expr ")" AE "(" section_subscript_list ")" AA For example some problems update only the interior of an array to keep the boundary constant as in G(2:N-1,2:N-1)=(u*G+(1-u)*G1)(2:N-1,2:N-1) which is a better way to write G(2:N-1,2:N-1)=u*G(2:N-1,2:N-1+(1-u)*G1(2:N-1,2:N-1) AEDetailed edits available in /x3j3/mullin.ps at ftp.ncsa.uiuc.edu.AA </SUGGESTED IMPLEMENTATION> <ESTIMATED IMPACT> This affects only new programs. It will not invalidate any existing programs. <SUBMITTED BY> Lenore R. Mullin, Scott Thibault, and Nicole Nemer Phone: 314-341-4492 Email: lenore@cs.umr.edu, sthib@cs.umr.edu, nnemer@cs.umr.edu </SUBMITTED BY> <HISTORY> <EVENT> Jul 94: Proposal submitted via email. </HISTORY> </FORTREQ> ---------------------------------------------------------------------- <FORTREQ> <NUMBER> 071 <TITLE> Linear array access <KEYWORDS> ARRAY ORDER LINEAR <STATUS> Registered <TARGET> <SUBGROUP> /OOF <VERSION> 1 <REQUIREMENT> The ability to access the linearly stored components of an array in memory. <JUSTIFICATION> Many languages access arrays in row major order. This would create a more ideal interface to language such as C where pointers could be used. <SUGGESTED IMPLEMENTATION> Since an array can be naturally thought of as a record it would be natural to access the linear stored components of an array as a record. As a record an array type would contain a dimension, size, and components field. The component field would be a vector. For example if A is a 2-D n-by-m array then A%component(2*n+2)=5 is equivalent to A(2,2)=5 AEDetailed edits available in /x3j3/mullin.ps at ftp.ncsa.uiuc.edu.AA </SUGGESTED IMPLEMENTATION> <ESTIMATED IMPACT> This affects only new programs. It will not invalidate any existing programs. <SUBMITTED BY> Lenore R. Mullin, Scott Thibault, and Nicole Nemer Phone: 314-341-4492 Email: lenore@cs.umr.edu, sthib@cs.umr.edu, nnemer@cs.umr.edu </SUBMITTED BY> <HISTORY> <EVENT> Jul 94: Proposal submitted via email. </HISTORY> </FORTREQ> ---------------------------------------------------------------------- <FORTREQ> <NUMBER> 072 <TITLE> Intrinsic function REVERSE <KEYWORDS> INTRINSIC FUNCTION REVERSE ARRAY <STATUS> Registered <TARGET> <SUBGROUP> /JOR <VERSION> 1 <REQUIREMENT> Addition of an intrinsic function that reverses the elements of an array. <JUSTIFICATION> Convolutions such as transpose and reverse are frequently used. The addition of monolithic arrays necessitates operation on monolithic arrays with the ability to define the axis of rotation for generality. <SUGGESTED IMPLEMENTATION> Define the intrinsic function REVERSE(A,DIM) where A is an array and DIM is the dimension to be reversed. DIM is optional and defaults to the first dimension. REVERSE would simply reverse the elements in a particular dimension. Convolution is one widely used operation that uses reverse. The convolution of two vectors could be written V*REVERSE(V) with the new intrinsic function. AEDetailed edits available in /x3j3/mullin.ps at ftp.ncsa.uiuc.edu.AA </SUGGESTED IMPLEMENTATION> <ESTIMATED IMPACT> This affects only new programs. It will not invalidate any existing programs. <SUBMITTED BY> Lenore R. Mullin, Scott Thibault, and Nicole Nemer Phone: 314-341-4492 Email: lenore@cs.umr.edu, sthib@cs.umr.edu, nnemer@cs.umr.edu </SUBMITTED BY> <HISTORY> <EVENT> Jul 94: Proposal submitted via email. </HISTORY> </FORTREQ> ---------------------------------------------------------------------- <FORTREQ> <NUMBER> 073 <TITLE> Multi-dimensional transpose <KEYWORDS> TRANSPOSE INTRINSIC FUNCTION ROW-MAJOR COLUMN-MAJOR ARRAY <STATUS> Registered <TARGET> <SUBGROUP> <VERSION> 1 <REQUIREMENT> Allow the transposition of array with a dimension greater than two. <JUSTIFICATION> Extensions are suggested for consistency and generality in the language. It may be desirable to transpose over an arbitrary dimension of an n-dimensional array. <SUGGESTED IMPLEMENTATION> The transpose of a n dimensional array is a rotation of the array about a particular axis. For n > 2 there is more than one rotation that can be performed. The particular rotation can be specified by a permutation vector of length n. The permutation vector describes how to permute the indices of the transposed array to access the original array. For example 2-D transpose would have the permutation vector (/ 2, 1 /) meaning the component (i,j) in the transposed matrix is the same as component (j,i) in the original matrix. The higher dimension transpose could use to provide compatibility. In order to interface other languages that do not use column-major ordering the components of array arguments must be reordered. This can be done with transpose. For example to convert the three dimensional array A to row-major order we could compute TRANSPOSE(A,(/ 3, 2, 1 /)). This permutation vector would be an extra argument to the transpose function and a default permutation could be chosen as a default value so that the argument is optional. TRANSPOSE(A,PERM) would transpose A with permutation vector PERM. PERM is optional and its default value is (/ d, (d-1), ... 1 /) where d is the dimension of A. TRANSPOSE(MATRIX) would still have the original semantics of 2-D transpose. AEDetailed edits available in /x3j3/mullin.ps at ftp.ncsa.uiuc.edu.AA </SUGGESTED IMPLEMENTATION> <ESTIMATED IMPACT> This affects only new programs. It will not invalidate any existing programs. <SUBMITTED BY> Lenore R. Mullin, Scott Thibault, and Nicole Nemer Phone: 314-341-4492 Email: lenore@cs.umr.edu, sthib@cs.umr.edu, nnemer@cs.umr.edu </SUBMITTED BY> <HISTORY> <EVENT> Jul 94: Proposal submitted via email. </HISTORY> </FORTREQ> -- Leonard J. Moss <ljm@slac.stanford.edu> o/ My views don't necessarily Stanford Linear Accelerator Center o/ reflect those of SLAC, MS 97; P.O. Box 4349; Stanford, CA 94309 o/ Stanford or the DOE