From 81117fb87ae3edb8b7bb31962f52b8c85af431fa Mon Sep 17 00:00:00 2001 From: Michael Abed Date: Sat, 7 Apr 2012 23:14:54 -0400 Subject: update --- computeTrussCost.m | 16 +++------------- truss_solver.m | 13 ++++++++++--- weakestMember.m | 13 ++++++++++++- 3 files changed, 25 insertions(+), 17 deletions(-) diff --git a/computeTrussCost.m b/computeTrussCost.m index df7daad..e3fed5d 100755 --- a/computeTrussCost.m +++ b/computeTrussCost.m @@ -1,15 +1,5 @@ -function [ cost ] = computeTrussCost( C, X, Y ) +function [ cost ] = computeTrussCost( C, D ) cost = 0; - [ j, m ] = size(C); - cost = cost + 10*j; - for i = 1:m - memb = C(:,i); - points = [X(memb == 1); Y(memb == 1)]; - d = dist(points(:,1), points(:,2)); - cost = cost + d; - end + [ j, ~ ] = size(C); + cost = cost + 10*j + sum(D); end - -function [ d ] = dist(p1, p2) - d = sqrt((p1(1)-p2(1))^2+(p1(2)-p2(2))^2); -end \ No newline at end of file diff --git a/truss_solver.m b/truss_solver.m index 4a7a1aa..50086f3 100755 --- a/truss_solver.m +++ b/truss_solver.m @@ -8,6 +8,13 @@ forces(abs(forces) < 0.00001) = 0; [j, m] = size(C); Ln = L(L~=0); + +D = memberDistances(C, X, Y); + +cost = computeTrussCost(C,D); +weakest = weakestMember(D,forces); +ml = maxLoad(forces,L,D,weakest); + for i = 1:length(Ln) fprintf('Load: %.3f N\n', abs(Ln(i))); @@ -21,7 +28,7 @@ for i = 1:length(forces)-m fprintf('r%d: %.3f\n', i, forces(m+i)); end -cost = computeTrussCost(C, X, Y); fprintf('Cost of truss: $%d\n', round(cost)); - -fprintf('Theoretical max load/cost ratio in N/$: %.4f\n', abs(sum(L))/cost); \ No newline at end of file +fprintf('Theoretical max load is %.4f\n', ml); +fprintf('Theoretical max load/cost ratio in N/$: %.4f\n', ml/cost); +fprintf('First member to break is member %d\n', weakest); \ No newline at end of file diff --git a/weakestMember.m b/weakestMember.m index 60485c9..6b67d64 100755 --- a/weakestMember.m +++ b/weakestMember.m @@ -1,3 +1,14 @@ -function [ idx ] = weakestMember(C, X, Y, T) +function [ idx ] = weakestMember(D, T) + unit = T(1:length(T)-3)/norm(T(1:length(T)-3)); + resist = breaking(D); + p = unit ./ resist; + p(p > 0) = 0; + a = 1:length(D); + [~,i] = max(abs(p)); + idx = a(i); +end + +function [ F ] = breaking(L) + F = 369.9 ./ (abs(L) .^ 1.465); end \ No newline at end of file -- cgit v1.2.3-54-g00ecf