Creating a matrix from a vector (using arrays)
in [SAS]
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From: TFriis on 27 Apr 2010 08:19 Hey. I am trying to convert this vba code to sas code; For i = 1 To Range("A1").End(xlDown).Row For j = 1 To Range("A1").End(xlDown).Row If i = j Then Cells(i, j + 2).Formula = "=0" Else: Cells(i, j + 2).Formula = "=A" & i & "*A" & j End If Next j Next i Range A contains a vector of values, this vector is made into a matrix with zeroes in the diagonal and multiples else where. I'm trying to do this with arrays, but they don't act like they should! (my code so far) data abc; input Conc @@; cards; 12 13 14 15 16 17 ; run; proc sql noprint; select count(*) into :OBSCOUNT from work.abc; quit; run; data new; array a{&obscount} ; array b{&obscount,&obscount}; do i = 1 to &obscount; set work.abc; a{i} = Conc; end; do i=1 to &obscount; do j=1 to &obscount; set work.abc; b{i,j}=a[i]*a[j]; output; end; end; drop i j; run; (haven't even begun to look at the diagonal, since this doesn't work!)
From: montura on 27 Apr 2010 10:25 I had the same problem when recoding a poisson function from VB to SAS. SCL arrays work exactly the same way as VB arrays. SCL arrays allows three or more dimensions, up to 99 dimensions if memory serves, while data step arrays are effectively limited to two dimensions.
From: Richard A. DeVenezia on 27 Apr 2010 11:17 On Apr 27, 8:19 am, TFriis <t.fr...(a)gmail.com> wrote: > Hey. > > I am trying to convert this vba code to sas code; > > For i = 1 To Range("A1").End(xlDown).Row > For j = 1 To Range("A1").End(xlDown).Row > If i = j Then > Cells(i, j + 2).Formula = "=0" > Else: > Cells(i, j + 2).Formula = "=A" & i & "*A" & j > End If > Next j > Next i > > Range A contains a vector of values, this vector is made into a matrix > with zeroes in the diagonal and multiples else where. > > I'm trying to do this with arrays, but they don't act like they > should! > > (my code so far) > > data abc; > input Conc @@; > cards; > 12 13 14 15 16 17 > ; > run; > > proc sql noprint; > select count(*) > into :OBSCOUNT > from work.abc; > quit; > run; > > data new; > array a{&obscount} ; > array b{&obscount,&obscount}; > do i = 1 to &obscount; > set work.abc; > a{i} = Conc; > end; > do i=1 to &obscount; > do j=1 to &obscount; > set work.abc; > b{i,j}=a[i]*a[j]; > output; > end; > end; > drop i j; > run; > > (haven't even begun to look at the diagonal, since this doesn't work!) Perhaps part of your problem is that the VBA code populates cells in a rectangle -- a table if you will. The code shown above populates a two dimensional array resulting in NxN columns in and output table having N rows. In order to create a table that looks like your matrix you will need to have N columns and N rows. ------------ data vector; input Conc @@; cards; 12 13 14 15 16 17 ; run; proc sql noprint; select count(*) into :COUNT from work.vector; quit; data myMatrix; array values(&count) _temporary_; do _n_ = 1 to dim(values); set vector; values(_n_) = conc; end; array cell(&count); do i = 1 to dim(values); do j = 1 to dim(values); if i = j then cell(j) = 0; else cell(j) = values(i) * values(j); end; OUTPUT; end; format cell: 6.; keep cell:; run; ------------ Richard A. DeVenezia http://www.devenezia.com
From: montura on 27 Apr 2010 12:23 If the full solution is fairly simply then Richards 2D posting will work. If multiple arrays, 2D and 3D, are necessary, email me direct and I will show you that SCL structure.
From: Richard A. DeVenezia on 27 Apr 2010 12:33
On Apr 27, 10:25 am, montura <montura...(a)gmail.com> wrote: > I had the same problem when recoding a poisson function from VB to > SAS. > SCL arrays work exactly the same way as VB arrays. > > SCL arrays allows three or more dimensions, up to 99 dimensions if > memory serves, while > data step arrays are effectively limited to two dimensions. This is patently wrong. DATA Step arrays can have any number of dimensions. A variable based array is limited to the maximum number of variables in the PDV. From the help file: " Note: Starting with SAS 9.1, the maximum number of variables can be greater than 32,767. The maximum number depends on your environment and the file's attributes. For example, the maximum number of variables depends on the total length of all the variables and cannot exceed the maximum page size. " -- Richard A. DeVenezia http://www.devenezia.com |