Aptech Systems, Inc. Worldwide Headquarters
Aptech Systems, Inc.
2350 East Germann Road, Suite #21
Chandler, AZ 85286
Ready to Get Started?
For Pricing and Distribution
Training & Events
Step-by-step, informative lessons for those who want to dive into GAUSS and achieve their goals, fast.
Have a Specific Question?
Q&A: Register and Login
Premier Support and Platinum Premier Support are annually renewable membership programs that provide you with important benefits including technical support, product maintenance, and substantial cost-saving features for your GAUSS System or the GAUSS Engine.
Join our community to see why our users are considered some of the most active and helpful in the industry!
Where to Buy
Available across the globe, you can have access to GAUSS no matter where you are.
Recent Tagsapplications character vectors CML CMLMT Constrained Optimization datasets dates dlibrary dllcall error error handling errors Excel FANPACMT file i/o floating network GAUSS Engine graphics GUI hotkeys installation Java API license licensing linux loading data matrices matrix matrix manipulation Maxlik MaxLikMT Memory Optmum output PQG graphics proc procs RAM random numbers string functions strings structures threading Time Series writing data
Time Series 2.0 MT
Find out more now
Time Series MT 2.1
is there a command to create a matrix which is all possible permutation of k elements of vector X. Basically, I am looking for an GAUSS equivalence for “perms” and “unique” commands of Matlab.
Thanks in advance!
Regarding <tt>unique</tt>, GAUSS has a function called <tt>unique</tt> that returns a sorted vector with duplicates removed.
Thanks for this. But I guess perms has no equivalence.
There are currently procedures in the Time Series MT that list permutations and combinations, with and without replacement, given the number of objects and the number of “choice”. However, none of these procedures produce the possible permutations given a vector of values.
I believe the three procedures below should allow you to create a matrix of all possible permutation of k elements of vector X. The first of these procedure most directly answers your question and will produce all possible permutations without allowing for replacement of values:
/* **> permVec ** ** Purpose: Calculates the number of permutations without replacement ** ** Format: perms = permVec(x) ** ** Input: x - Vector n x 1, vector for permutation ** ** ** Output: perms - Matrix, list of all possible permutations of the vector x ** without replacement. */ proc (1) = permVec(x); local n,k,x2,x3,tmp,i,e; n = cols(X); k = cols(X); x2 = permReplaceVec(x); //Delete rows with duplicate value x3 = uniqMat(x2); retp(x3); endp;
This procedure calls the two procedures other procedures, permReplaceVec and uniqMat. The first of these, perReplaceVec lists all possible permutations of a vector X allowing for replacement of values:
/* **> permReplaceVec ** ** Purpose: Calculates the number of permutations without replacement ** ** Format: perms = permReplaceVec(x) ** ** Input: x - Vector n x 1, vector for permutation ** ** ** Output: perms - Matrix, list of all possible permutations of the vector x ** with replacement. */ proc (1) = permReplaceVec(x); local nstates, base_idx, c, r, out, base, numiters, numset, k; nstates = rows(x); k = rows(x); c = k; r = nstates^k; out = ones(r, c); base = reshape(seqa(1, 1, nstates), r, 1); for i(1, c-1, 1); numset = nstates^(k-i); base_idx = 1; for j(1, r, numset); out[j:(j+numset-1), i] = base[base_idx].* ones(numset,1); base_idx = base_idx + 1; endfor; endfor; //avoid last iteration of for loop for speed up out[., c] = base; //Matrix Replace for i(1,nstates,1); out = missrv(miss(out,i),x[i]); endfor; retp(out); endp;
The second procedure, uniqMat, deletes all rows from a matrix which include repeated values:
/* **> uniqMat ** ** Purpose: Deletes rows of x which include repeated values ** ** Format: newX = uniqMat(x) ** ** Input: x - Matrix n x k, vector for permutation ** ** ** Output: newX - Matrix, includes only rows of x. */ proc (1) = uniqMat(x2); local tmp, new_X, x3,j; new_X = zeros(rows(X2),1); for i(1,rows(X2),1); tmp = unique(X2[i,.],1); if rows(tmp)!= cols(x2[i,.]); new_X[i,.]=i; endif; endfor; new_X = packr(miss(new_X,0)); x3 = delrows(x2,new_X); retp(x3); endp;
Try the following code as an example:
x = rndn(4,1); x; x2 = permReplaceVec(x); x2; x3 = permVec(x); x3;