seb/XM_40017
1
0
Fork 0
mirror of https://github.com/fverdugo/XM_40017.git synced 2025-11-08 23:24:25 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity

Merge pull request #62 from fverdugo/francesc

Browse Source 
More work for ASP
This commit is contained in:
Francesc Verdugo 2024-09-26 11:13:52 +02:00 committed by GitHub
commit e4eea0da0a
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
2 changed files with 39 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

37
docs/src/solutions_for_all_notebooks.md
View File

@ -395,5 +395,42 @@ function jacobi_mpi(n,niters,tol,comm) # new tol arg
end
```
## All pairs of shortest paths
### Exercise 1
```julia
function floyd_iterations!(myC,comm)
L = size(myC,1)
N = size(myC,2)
rank = MPI.Comm_rank(comm)
P = MPI.Comm_size(comm)
lb = L*rank+1
ub = L*(rank+1)
C_k = similar(myC,N)
for k in 1:N
if (lb<=k) && (k<=ub)
# If I have the row, fill in the buffer
myk = (k-lb)+1
C_k[:] = view(myC,myk,:)
end
# We need to find out the owner of row k.
# Easy since N is a multiple of P
root = div(k-1,L)
MPI.Bcast!(C_k,comm;root)
# Now, we have the data dependencies and
# we can do the updates locally
for j in 1:N
for i in 1:L
myC[i,j] = min(myC[i,j],myC[i,k]+C_k[j])
end
end
end
myC
end
```

4
notebooks/asp.ipynb
View File

@ -57,7 +57,7 @@
"function q1_answer(bool)\n",
" bool || return\n",
" msg = \"\"\"\n",
" The we can change the loop order over i and j without changing the result. Rememebr:\n",
" The we can change the loop order over i and j without changing the result. Rememeber:\n",
" \n",
" C[i,j] = min(C[i,j],C[i,k]+C[k,j])\n",
" \n",
@ -858,7 +858,7 @@
" P = MPI.Comm_size(comm)\n",
" lb = L*rank+1\n",
" ub = L*(rank+1)\n",
" C_k = similar(C,N)\n",
" C_k = similar(myC,N)\n",
" for k in 1:N\n",
" if (lb<=k) && (k<=ub)\n",
" # Send row k to other workers if I have it\n",