I am learning Bender's decomposition method and I want to use that in a small instance. I started from "bendersatsp.py" example in CPLEX. When I run this example with my problem, I got the following error. Could you please let me know what the problem is and how I can fix it? In the following you can see the modifications in lazy constraints function. I have two decision variables in master problem "z_{ik}" and "u_{k}" that would incorporate as constant in the workerLp.
class BendersLazyConsCallback(LazyConstraintCallback):
def __call__(self):
print("shoma")
v = self.v
u = self.u
z = self.z
print ("u:", u)
print ("z:", z)
workerLP = self.workerLP
boxty = len(u)
#scenarios=self.scenarios2
ite=len(z)
print ("ite:", ite)
print ("boxty:", boxty)
# Get the current x solution
sol1 = []
sol2 = []
sol3 = []
print("okkkk")
for k in range(1, boxty+1):
sol1.append([])
sol1[k-1]= [self.get_values(u[k-1])];
print ("sol1:", sol1[k-1])
for i in range(1, ite+1):
sol2.append([])
sol2[i-1]= self.get_values(z[i-1]);
print ("sol2:", sol2[i-1])
for i in range(1, ite+1):
sol3.append([])
sol3[i-1]= self.get_values(v[i-1]);
#print ("sol3:", sol3[i-1])
# Benders' cut separation
if workerLP.separate(sol3,sol1,sol2,v,u,z):
self.add(cut = workerLP.cutLhs, sense = "G", rhs = workerLP.cutRhs)
CPLEX Error 1006: Error during callback.
benders(sys.argv[1][0], datafile)
cpx.solve()
_proc.mipopt(self._env._e, self._lp)
check_status(env, status)
raise callback_exception
TypeError: unsupported operand type(s) for +: 'int' and 'list'
function []= read_c3d_feat(output_list_relative)
dir_list = importdata(output_list_relative);
dim_feat = 512;
for i = 1 : size(dir_list, 1)
dir_str = char(dir_list(i));
feat_files = dir([dir_str, '/*.res5b']);
num_feat = length(feat_files);
feat = zeros(num_feat, dim_feat);
for j = 1 : num_feat
feat_path = strcat(dir_str, '/', feat_files(j).name);
...............
....................so on
Give me error like
Error using dir
Invalid path. The path must not contain a null character.
Error in read_c3d_feat (line 12)
feat_files = dir([dir_str, '/*.res5b']);
Your dir_list variable must have strings which contain null characters, as the error tells you. If you try using hard-coded strings you will see it works:
function read_c3d_feat(output_list_relative)
dir_list = {'21';'45';'18'};
for i = 1:size(dir_list, 1)
dir_str = dir_list{i}; % Loops through '21','45','18'
% The dir function now works because we know dir_str is a valid string
feat_files = dir([dir_str, '/*.res5b']);
end
end
This means you need to debug your code and find out what this line is actually assigning to dir_list:
dir_list = importdata(output_list_relative);
Note that if dir_list is a cell of text entries, you should be indexing it with curly braces as above. If instead it is a matrix (because all of the entries seem to be numerical anyway) then you should be using num2str when passing to dir:
function read_c3d_feat(output_list_relative)
dir_list = importdata(output_list_relative);
dim_feat = 512;
for i = 1:size(dir_list, 1)
feat_files = dir([num2str(dir_list(i)), '/*.res5b']);
% ...
I wanted to run this line but unfortunately it throws an error. Any ideas?
Undefined function or variable mr.
Error in Playground (line 23)
X = min(mr);
j = 1;
for i = 1:(resolution1+1)
line(i) = m(a(1))*ab(i)+c;
end
for i = 1:(resolution1)
if or(or(line(i)>ab_y(i) & line(i+1)<ab_y1(i+1),line(i)<ab_y1(i)& line(i+1)>ab_y1(i+1)),line(i)==ab_y1(i))
mr(j) = ab1(i);
rk(j) = ab_y1(j);
j = j+1;
end
end
X = min(mr);
Y = max(mr);
Your condition:
or(or(line(i)>ab_y(i) & line(i+1)<ab_y1(i+1),line(i)<ab_y1(i)& line(i+1)>ab_y1(i+1)),line(i)==ab_y1(i))
returns always false, so the statements inside
mr(j)=ab1(i); rk(j)=ab_y1(j);
are never executed. Therefore variable mr does not exist.
Add an mr = []; statement before the loop to initialize the variable (and also revise your condition why it returns always false).
class Matrix:
def __init__(self, nr, nc):
self.NRows = nr
self.NCols = nc
self.data = [ [0]*self.NCols for r in range(self.NRows) ]
def max(self, other):
""" return: a matrix with as many rows as the shorter of self and other and as many columns as the narrower of self and other.
Each entry of the returned matrix should be the larger (the max) of the corresponding entries in self and other.
"""
minrows = min(other.NRows, self.NRows)
mincols = min(other.NCols, self.NCols)
M = Matrix(minrows, mincols)
for i in range(minrows):
for j in range(mincols):
M.data[i][j] = max(self.data[i][j], other[i][j])
return M
This code give Traceback in max when tested and output said:
...in max
M.data[i][j] = max(self.data[i][j], other[i][j])
AttributeError: Matrix instance has no attribute '__getitem__'
How to get rid of this error? Where I made mistake?. Please help someone.
You should use this :
M.data[i][j] = max(self.data[i][j], other.data[i][j])
instead of
M.data[i][j] = max(self.data[i][j], other[i][j])
I am new in matlab I am trying to define a function and I keep getting this error
" input argument "ip" is undefined.
Error in ==> edge_mapping at 2
size_ip = size(ip(:,:,1)); "
here is my code
function[op1,op2,op3] = edge_mapping(ip)
size_ip = size(ip(:,:,1));
s=size_ip(1);
op1= cat(3,zeros(s),zeros(s),zeros(s),zeros(s),zeros(s),zeros(s),zeros(s),zeros(s),zeros(s),zeros(s));
op2= cat(3,zeros(s),zeros(s),zeros(s),zeros(s),zeros(s),zeros(s),zeros(s),zeros(s),zeros(s),zeros(s));
op3= cat(3,zeros(s),zeros(s),zeros(s),zeros(s),zeros(s),zeros(s),zeros(s),zeros(s),zeros(s),zeros(s));
for i = 1 : 10
op1(:,:,i)=edge(ip(:,:,i),'sobel');
op2(:,:,i)=edge(ip(:,:,i),'prewitt');
op3(:,:,i)=edge(ip(:,:,i),'canny');
end
function [op1, op2, op3] = edge_mapping(ip)
op1 = zeros(size(ip));
op2 = zeros(size(ip));
op3 = zeros(size(ip));
for i = 1 : size(ip, 3)
op1(:,:,i)=edge(ip(:,:,i),'sobel');
op2(:,:,i)=edge(ip(:,:,i),'prewitt');
op3(:,:,i)=edge(ip(:,:,i),'canny');
end
return
But I think it's better to write a simple function:
function op = edge_mapping(ip, edge_mode)
op = zeros(size(ip));
for i = 1 : size(ip, 3)
op(:,:,i)=edge(ip(:,:,i), edge_mode);
end
return
and then call it:
op_sobel = edge_mapping(ip, 'sobel');
op_prewitt = edge_mapping(ip, 'prewitt');
op_canny = edge_mapping(ip, 'canny');
This code is a function. It has to be save as m-file and run from MATLAB command line, script or another function as
[op1,op2,op3] = edge_mapping(ip);
where arguments ip, op1, op2, and op3 can have different names.
Make sure you have space after function keyword.
To avoid this error you can assign a default value for the input argument if it's undefined (not exist in the function's scope):
if ~exist(ip, 'var')
ip = []; %# or other default value
end