Why not use a table?   proc iml; t = TableCreateFromDataSet("Sashelp", "Class"); NewWeight = TableGetVarData(t, "Weight")#2; call TableAddVar(t, "NewWeight", NewWeight); call TableWriteToDataSet(t, "work", "NewClass"); quit; proc print data=NewClass; run; ... View more

Indeed size matters, so you need to be aware that nrow(A)*nrow(B) is not too large if vectorization is to be used.  I compared result = (t(B) <= repeat(A,1,nrow(B)))[,+]; to result = (repeat(t(B),nrow(A),1) <= repeat(A,1,nrow(B)))[,+]; using FULLSTIMER and I am seeing that the latter uses about 50% more memory for a moderately large problem (10000 x 32), so there is some saving comparing vector to matrix, over matrix to matrix.     ... View more

I think you can avoid the need to check for an empty result if you vectorize it as follows:   A = {10, 3, 19} ; B= {1, 3, 7, 42}; result = (t(B) <= repeat(A,1,nrow(B)))[,+]; print result; ... View more

Thanks for your kind words.  I should make it clear that I did exactly what you proposed to do above, and started from the code in the package.  So I would like to acknowledge Rick for writing the original ListPrint - I definitely learned a few things from his code! ... View more

You can see the source code by running: package info listutil; This will tell you the name of the directory where the package is stored and the IML code should be in the sub-directory called 'source'.  There is no need to rewrite ListPrint, you are welcome to use my version below. proc iml; start L_Print( L, UseNames=0, labl=("--------- List = " + parentname("L") + "---------"), maxdepth=30); if type(L) ^= 'L' then return; /* i indexes items at each depth, n is the list length at each depth. */ i = j(1, maxdepth, 0); n = j(1, maxdepth, 0); vnam = 'nam1':('nam'+char(maxdepth)); nstr = j(1, maxdepth, blankstr(40)); d = 1; /* the current depth in the list */ print labl[L=""]; nam1 = ListGetAllNames( L ); n[1] = ListLen( L ); if ncol(nam1)=0 then nam1 = char(1:n[1]); do until( (d = 0) | (d > maxdepth) ); i[d] = i[d] + 1; if i[d] <= n[d] then do; x = ListGetSubItem( L, i[1:d] ); nstr[d] = value(vnam[d])[i[d]]; if nstr[d] = ' ' then nstr[d] = char(i[d]); if UseNames then msg = cats(parentname('L'),rowcatc( "['" + nstr[,1:d] + "']")); else msg = cats(parentname('L'),rowcatc( '[' + char(i[,1:d]) + ']')); if type(x)='U' then print ('Undefined') [label=msg]; else if type(x)='C' | type(x)='N' then do; if ncol(x)=1 then x = t(x); print x[label=msg]; end; else if type(x)='T' then call TablePrint(x) label=msg; else if type(x)='L' then do; print (cshape('[',1,1,d) + ' LIST ' + cshape(']',1,1,d)) [label=msg]; d = d + 1; n[d] = ListLen(x); tn = ListGetAllNames(x); if ncol(tn)=0 then tn = char(1:n[d]); call ValSet(vnam[d], tn); end; end; else do; i[d] = 0; d = d - 1; /* move up the list one level */ end; end; finish; L = [ #'L1' = [ #'L2' = [ #'L3' = [ #'L4' = []]]]] ; call L_print( L, 1 ) ; quit; ... View more

Thank you Rick, I see how to do it now.  So following your example I could make my own version of ListAddSubItem as follows: proc iml; start ListAddSubItem(A, Pos, Val); if type(A) ^= 'L' then return; B = ListGetSubItem(A, Pos, 'm'); if type(B) = 'L' then call ListAddItem(B, Val); call ListSetSubItem(A, Pos, B, 'm'); finish; package load listutil; L = [ 2, [5, 6], 9 ]; call ListAddSubItem(L, 2, 7); call struct(L); quit; ... View more

Here is an example.  If I create a list with 3 items where the second item is itself a list - like this: L = [[1:3], [i(2),i(3)], [4:6]]; Then I might want to add i(4) to the sublist.   I have tried syntax like: Call ListAddItem(L$2, i(4)); but this, and using L[2] instead of L$2, both leave L unmodified. If by being clever you mean something like: L$2 = [ L$2 || [i(4)] ]; then this works but essentially I have just manually reconstructed L$2.  It feels like there should be a subroutine called ListAddSubItem to do what I want, but it is not there. ... View more

Hi Rick, Can you give an example of how you can use ListAddItem to extend a sublist?  I can make it work at the top level, but not lower down in the hierarchy. ... View more

Because ListShape handles lists of lists, you can even specify each row of the matrix that you want to construct with it own list - this may seem a more natural syntax.  For example: z = ListShape( [ [5, -sqrt(2)], [-sqrt(2), 3] ], 2, 2); will give z 5 -1.414214 -1.414214 3 ... View more

Expressions are allowed when creating a list, so I thought that another way to get what you want is to use a helper function to extract the numeric data from a list, and convert it into a single matrix.  Essentially this is generalizing the shape function to a list.  For example: proc iml; /* Concatenate all numeric items in a list and return the reshaped data in the form of a nr*nc matrix. Sublists upto a depth of maxdepth are searched for data. */ start ListShape(L, nr, nc); if type(L) ^= 'L' then return; maxdepth = 20; /* idx used as loop variable at each depth, ni is the list length at each depth */ idx = j(1, maxdepth, 0); ni = j(1, maxdepth, 0); d = 1; /* the current depth in the list */ do until( d = 0 ); if idx[d] = 0 then if d = 1 then ni[d] = ListLen( L ); else ni[d] = ListLen( ListGetSubItem( L, idx[1:(d-1)]) ); idx[d] = idx[d] + 1; if idx[d] <= ni[d] then do; x = ListGetSubItem( L, idx[1:d] ); if type(x) = 'N' then do; /* glue all data together into a column vector y */ y = y // shape(x, nrow(x)#ncol(x) ); end; else if type(x) = 'L' then d = d + 1; /* item is a list so move deeper */ end; else do; idx[d] = 0; d = d - 1; /* move up the list one level */ end; end; return(shape(y, nr, nc)); finish; z = ListShape( [5##2, -sqrt(2), -sqrt(2), 1:3], 3, 2); print z; quit; which produces: z 25 -1.414214 -1.414214 1 2 3 The ListShape function is effectively using concatenation within a loop, which will not be efficient with large amounts of data, but should be fine for the small examples given above. ... View more