x-ref: http://stackoverflow.com/questions/39039553/lower-triangular-matrix-in-julia-julia
On Fri, Aug 19, 2016 at 10:29 AM, Michael Krabbe Borregaard < mkborrega...@gmail.com> wrote: > A symmetric matrix and a lower triangular matrix are different things. > Look for what you want here: http://julia.readthedocs.io/ > en/latest/manual/linear-algebra/ and here: http://julia.readthedocs.io/ > en/latest/stdlib/linalg/ > > On Fri, Aug 19, 2016 at 4:07 PM, Ahmed Mazari <ahmedmazari...@gmail.com> > wrote: > >> 4×4 Array{Int64,2}: >> 0 1 2 3 >> 1 0 4 5 >> 2 4 0 6 >> 3 5 6 0 >> >> a symetric matrix m[i,j] =m[j,i] and m[i,i]= 0 >> >> On Fri, Aug 19, 2016 at 3:59 PM, Jeffrey Sarnoff < >> jeffrey.sarn...@gmail.com> wrote: >> >>> Is this what you want, or are you looking for a more general way to >>> construct nxn matrices like this 4x4 matrix, or something else? >>> >>> julia> m = [ [0,1,2,3] [1,0,4,5] [2,3,0,6] [4,5,6,0] ] >>> 4×4 Array{Int64,2}: >>> 0 1 2 4 >>> 1 0 3 5 >>> 2 4 0 6 >>> 3 5 6 0 >>> >>> >>> On Friday, August 19, 2016 at 9:01:06 AM UTC-4, Ahmed Mazari wrote: >>>> >>>> Yes but it doesn't allow me to set the diagonal to 0 ?? >>>> >>>> On Fri, Aug 19, 2016 at 2:55 PM, Michael Borregaard < >>>> mkborr...@gmail.com> wrote: >>>> >>>>> You can build the matrix as normal, then specify that the upper >>>>> triangle is undefined by >>>>> mat = LowerTriangular(mat) # where mat is a Matrix of any eltype. >>>>> >>>> >>>> >> >
