In Vellino sample, there are two variables and a constrains:

c = VarArray(size=nBins, dom=range(nColors))
p = VarArray(size=[nBins, nMaterials], dom=lambda i, j: range(min(maxCapacity, demands[j]) + 1))

satisfy(
# every bin with a real colour must contain something, and vice versa
[(c[i] == Unusable) == (Sum(p[i]) == 0) for i in range(nBins)],

# all components of each material are spread across all bins
[Sum(p[:, j]) == demands[j] for j in range(nMaterials)],

# the capacity of each bin is not exceeded
[Sum(p[i]) <= capacities[c[i]] for i in range(nBins)]

)

I am trying to reproduce the Warehouse Location problem shown in the docs. I am getting the title error as soon as I use the variable w for indexing:

minimize(
    # minimizing the cost of supplying stores
    Sum(costs[i][w[i]] for i in range(nStores))
);

Any hints?

Hi,

I have perused the documentation and source code and I couldn't find how select a heuristic for e.g variable selection. I guess it would be something like.

solve(options="varh dom/wdeg")

This obviously doesn't work, I would greatly appreciate an example. Thanks.

Some typos in the online documentation http://pycsp.org

- PyCSP3 documentation

• Le titre de la page est la forme ‘- PyCSP3 documentation’ : manque-t-il un ‘Homepage’ ?
• PySCP3 -> PyCSP3

Installation - PyCSP3 documentation

• Pas de souci, l’installation sur Mac se déroule bien.
• Pas nécessaire d’utiliser le sudo de mon côté.

QuickStart - PyCSP3 documentation

• Le lien de téléchargement des notebooks montrent le code source et ne produit pas le téléchargement de celui-ci :
  • <a href="/path/to/your/receipt.pdf" download>Download Receipt</a>
  • Le mot clé download le permet certainement

• L’exécution fonctionne bien.

• Le message Warning: Unknown option: -f apparait au moment de l’import

components - PyCSP3 documentation

• Pas de souci pour les notebooks variables, contraintes, … tous s’exécutent très bien.

Module - PyCSP3 documentation

• Certains caractères Latex : /status()/}: returns the result of the last solving process (last call to \nn{solve()})

Circuit - PyCSP3 documentation

• le Related Models de Mario renvoie vers une page 404
• C’est le cas ici aussi : Cumulative - PyCSP3 documentation
• Peut-être d’autres ?

Count - PyCSP3 documentation

• On can infer -> One can infer

ElementMatrix - PyCSP3 documentation

• at specified indexex -> at specified indexes

Extension - PyCSP3 documentation

• Sous le titre Case 3: Starred Tables, il y a des restes de latex pas interprété

Hello,

I want to build a CSP where I don't know in advance how many variables I need. It seems like this library is using the identifier name as the variable name in the xml file. Thus, I can't figure out how to add new variables on the fly. This is my best guess so far.

from pycsp3 import Var

variables = list()
for i in range(10):
    variables.append(None)
    variables[i] = Var(dom=[0, 1])

However, I get the following error

self.indexes = [int(v) for v in re.split("\]\[", self.suffix[1:-1])]
ValueError: invalid literal for int() with base 10: 'i'

I know I could pre-compute the exact number of variables I require beforehand, but I would prefer to generate the variables as I require them.

Is there a way to achieve that?

I am checking the specification of the instances in http://jobshop.jjvh.nl/instance.php?instance_id=84 and apparently, there is no correspondence between the data file that you provide and the specification of the corresponding instance. For example, I couldn't find a Job with the following durations: 86,60,10,59,65,94,71,25,98,49,43,8,90,21,73.

I tried to run PyCSP3/pycsp3/problems/tests/cop_acad.py and got the following trace (and error):

|================================================================|
  Python: python3 (Python 3.7.1)
  Name: BoardColoration
  Data: [8,10]
  Name XML: BoardColoration-8-10.xml
|================================================================|
Command: python3 ./pycsp3/problems/cop/academic/BoardColoration.py -data=[8,10]
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/shutil.py", line 557, in move
    os.rename(src, real_dst)
FileNotFoundError: [Errno 2] No such file or directory: 'BoardColoration-8-10.xml' -> './pycsp3/problems/tests/tmp/cop/academic/PyCSP/BoardColoration-8-10.xml'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/Users/kyzrsoze/Sources/PyCSP3/pycsp3/problems/tests/cop_acad.py", line 25, in <module>
    .add("WaterBucket", data="[8,5,3,4,4,0,8]")  # optimum 7
  File "/Users/kyzrsoze/Sources/PyCSP3/pycsp3/problems/tests/tester.py", line 40, in run
    xcsp.load(mode=2)
  File "/Users/kyzrsoze/Sources/PyCSP3/pycsp3/problems/tests/tester.py", line 218, in load
    shutil.move(self.name_xml, self.xml_path_py())
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/shutil.py", line 571, in move
    copy_function(src, real_dst)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/shutil.py", line 257, in copy2
    copyfile(src, dst, follow_symlinks=follow_symlinks)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/shutil.py", line 120, in copyfile
    with open(src, 'rb') as fsrc:
FileNotFoundError: [Errno 2] No such file or directory: 'BoardColoration-8-10.xml'

PyCSP stderr : 
/Library/Frameworks/Python.framework/Versions/3.7/Resources/Python.app/Contents/MacOS/Python: can't open file './pycsp3/problems/cop/academic/BoardColoration.py': [Errno 2] No such file or directory


Process finished with exit code 1

Do you have any idea how I can fix that?
In addition, I would appreciate if I could set the solver in __init__() of Tester.

Thank you

Have a look at:
https://github.com/xcsp3team/pycsp3/blob/6a66bc6f78d10ec0bc195e8bad3af5f3f547260c/problems/g6_testing/TestAbscon.py#L18

I bet a call to AbsCon would be more convenient.

Please bear with me if this is not how one raises issues in Github. I am a new user of GitHub

I encountered a ValueError while running a program that uses the pyCSP3 library. The issue arises when using the predicate 0.5 in a particular context. Below is the traceback information for reference:

Traceback (most recent call last):
File "c:\Users\h.kumaravel\Documents\Python\Extras\CSP.py", line 103, in
minimize(Sum(x[i]-x[i-1]*0.5-x[i+1]*0.5 for i in range(1,len(x)-1)))
File "C:\Users\h.kumaravel\AppData\Local\Programs\Python\Python310\lib\site-packages\pycsp3\functions.py", line 1001, in Sum
terms = flatten(list(term)) if isinstance(term, types.GeneratorType) else flatten(term, others)
File "c:\Users\h.kumaravel\Documents\Python\Extras\CSP.py", line 103, in
minimize(Sum(x[i]-x[i-1]*0.5-x[i+1]*0.5 for i in range(1,len(x)-1)))
File "C:\Users\h.kumaravel\AppData\Local\Programs\Python\Python310\lib\site-packages\pycsp3\tools\curser.py", line 372, in mul
return Node.build(TypeNode.MUL, self, other)
File "C:\Users\h.kumaravel\AppData\Local\Programs\Python\Python310\lib\site-packages\pycsp3\classes\entities.py", line 687, in build
node = Node(type, Node._create_sons(*args))
File "C:\Users\h.kumaravel\AppData\Local\Programs\Python\Python310\lib\site-packages\pycsp3\classes\entities.py", line 669, in _create_sons
raise ValueError("Problem: bad form of predicate " + str(arg))
ValueError: Problem: bad form of predicate 0.5

• Python Version: 3.10.10
• CSP Library Version: 2.1.2

Please let me know if you require any further information. Thank you!

When calling a python file, named csp.py, the xml output filename should be csp.xml, but if you add data using -data, the xml output filename becomes csp-data.xml

Hello !

I have a use case in which I have to solve several constraint problems but I don't know how to assign new variables without restarting the Python kernel.

Example :

for i in range(10):
  x = VarArray(10, [0,1])
  satisfy( blablabla)
  solve()

ERROR: The identifier x is used twice. This is not possible
(add option -ev to your command if you want to see the trace of the error)
An exception has occurred, use %tb to see the full traceback.
SystemExit: 1

Thanks !

Python 3.10.6 (default on Ubuntu 22.04) gives a syntax warning about the suspicious use of "is" instead of "==" in the condition on line 271 of compiler.py:

 if Compilation.filename is "" and options.output is not None:

When I read the line, I also assume Compilation.filname == "" is meant instead.

 if Compilation.filename == "" and options.output is not None:

I am currently working on a Constraint Optimization Problem (COP) using the pyCSP3 library. However, I encountered an error when trying to initialize the solve() function with the options parameter. The error message in the solver log file reads:

! ERROR: limit=60s is not put at the right position
Use the solver option -ev for more details

Here's the code snippet where the error occurs:

if solve(options=["limit=60s"]) in {SAT, OPTIMUM}:
print(f"Solution: {values(x)}")

To set a time limit of 60 seconds, I used the options parameter with the value "limit=60s". However, it seems that I am not passing the argument properly to the options parameter.

Could you please provide guidance on how to rectify this error and correctly pass the time limit argument to the options parameter in the solve() function?

Thank you for your assistance!

I think the BinPacking constraint has some problems. When I use the second variant (which requires the parameter limits) I get this error even using the basic problem of the documentation:

Model:

from pycsp3 import *

sizes = [10, 7, 3, 9, 5, 7, 8, 4, 6, 4]
nItems = len(sizes)

x = VarArray(size=10, dom={0, 1, 2})

satisfy(
BinPacking(x, sizes=sizes, limits=[23,20,21])
);

Error:

File "/Users/jlopez/PhD/RobustSolutions/ROADEF/basic_binPacking.py", line 9, in
BinPacking(x, sizes=sizes, limits=[23,20,21])
TypeError: BinPacking() got an unexpected keyword argument 'limits'
Warning: no constraints for this model!

Examples Auctions.py, SetCovering.py and SetPacking.py use a variable named "values" which collides with the pycsp3.values() function when including solving.

I am using Python 3.9.7 on MacOS 12.4 (21F79) on Apple Silicon. Trying to solve anything will result in UNKNOWN returned by the solver. The solver log file is empty.

To reproduce, the following example from the documentation fails to work:

from pycsp3 import *

n = 4
R, G, B = colors = 0, 1, 2

# x[i] is the color of the ith node
x = VarArray(size=n, dom=colors)
print("Array x: ", x)
print("Domain of any variable: ", x[0].dom)
satisfy(
    x[0] != x[2],

    x[1] != x[3]
);
if solve() is SAT:
    print(values(x))
satisfy(
    x[0] != x[1],

    x[1] == x[2],
    
    x[2] != x[3],
    
    x[3] == x[0]
);
if solve() is SAT:
    print(values(x))
if solve(sols=ALL) is SAT:
    print("Number of solutions: ", n_solutions())
print(solve())
```.

Running this results in the following output:

(base) felixbinder@Felixs-MacBook-Pro tools_block_construction_human_experiments % /Users/felixbinder/opt/anaconda3/bin/python "/Users/felixbinder/Cloud/Grad School/Fan L
ab/Block_Construction/tools_block_construction_human_experiments/stimuli/BIBD_test_main.py"
Array x: [x[0], x[1], x[2], x[3]]
Domain of any variable: 0 1 2
UNKNOWN

I've installed pycsp3 by running `sudo pip3 install pycsp3`.