pyomo specify solver location - pyomo

Seems pretty simple but how do I point Pyomo to a locally-installed solver? I was able to get a solution from NEOS from my local computer, so I know the model is appropriately designed. Yesterday I installed the COIN-OR tarfile onto an Azure Ubuntu VM and want to run my model on that VM using Jupyter.
Here's what I have so far:
solvername='ipopt'
solverpath_folder='~/COIN-OR/bin/'
solverpath_exe='~/COIN-OR/bin/ipopt'
solver=SolverFactory(solvername,executable=solverpath_exe)
instance = model.create_instance()
opt.solve(instance,solver)
Error messages:
WARNING: DEPRECATED: Cannot call Model.create_instance() on a constructed
model; returning a clone of the current model instance.
WARNING: Could not locate the 'ipopt' executable, which is required for solver
ipopt

To get rid of the first warning you're seeing, you don't need the create_instance call when you're working with concrete models.
To address the second warning and your question, we recommend adding the directory containing the solver executables to your search path by modifying the PATH environment variable. If you don't want to modify your search path then I would try specifying the path to the executable without using ~/ as a shortcut to your home directory.

Related

Error while building WSO2 Microgateway project on Windows 10

I’ve been trying to explore WSO2 Microgateway and set up a Microgateway project. Building the project in Windows 10 with the command “micro-gw build project-name” is giving this error: “Could not find or load main class org.wso2.apimgt.gateway.cli.cmd.Main”.
I’ve downloaded the Toolkit and Runtime from https://wso2.com/api-management/api-microgateway/. I've set the Path environment variable to the /bin directory of the Toolkit and Runtime extracted folders, but still the “micro-gw build project-name” command is giving error “Could not find or load main class org.wso2.apimgt.gateway.cli.cmd.Main”. I’ve also cloned the source code from Github (https://github.com/wso2/product-microgateway/) which has the Main.java class and tried setting environment variables to its path.
I also tried setting the environment variables to the path where Toolkit batch file is present. I also followed the steps mentioned here, https://github.com/wso2/product-microgateway/#running-the-microgateway.
I'm assuming the Toolkit batch file (micro-gw) would execute the Main.java class coming up in the error.
These steps did not resolve the error. I'm new to Java based product, and I'm sure I'm missing something here.
Problem is with the init command not the build command. Init command is suppose to setup the TOOLKIT after the first use. It should extract the platform.zip file and copy all of the required resources to relevant places for you.
I hope you get the Project ___ successfully initialized message after running the init command. Just check $TOOLKIT_HOME/logs/ directory to see if there are any information on the log file.
If the log file also doesn't help, as a workaround, copy all the .jar files inside $TOOLKIT_HOME/lib/gateway/platform and $TOOLKIT_HOME/lib/gateway/cli to $TOOLKIT_HOME/lib/platform/bre/lib and try again, that should work.
Also please report this issue at https://github.com/wso2/product-microgateway/issues

How can I make LLVM display graphs in a different viewer?

LLVM can create graphs in Graphviz's "dot" format, and automatically invoke a viewer to display them. By default it uses dotty to display those graphs. I know that I can change it to use a different viewer, but I was not able to find precise instructions on how to do so.
How can I make it open the graphs with a different viewer?
I'm running on Linux but would be interested in an answer for Windows as well.
I found out I'm supposed to change the CMakeCache.txt file in my build folder. For instance, to use XDot instead of dotty, I edited the LLVM_PATH_XDOT_P property in that file to point to the full path of my xdot.py file.
It now opens the alternative viewer successfully, after rebuilding the project.
I just needed to do this.
I managed to do this with a workaround: made a backup of dotty (just in case) and created a link from dotty to XDot.
cp /usr/bin/dotty /usr/bin/dotty_copy
ln -s /usr/bin/dotty /usr/bin/xdot
I believe you could also set some variable during configuration step (possibly LLVM_PATH_DOTTY), but I never tried this as I didn't want to recompile LLVM.
You may try hacking the DisplayGraph function or fidging with the makefiles until you manage to enable one of the #ifdefs in DisplayGraph.

django runserver error from SVN co

I have written a Django project which runs fine on the dev server. Although I am the only one working on it, I realized I should get some sort of version control going and placed the project on a network SVN. I assume the new process for working this project should be: checkout code from SVN, make changes, test, update, and commit back to SVN.
However, when I check out the code and attempt to run the dev server from the checked out SVN location, I get an error that "has no module named yadda.yadda". But, the module is there and it works fine when I run it from the original directory. Any thoughts? Any suggestions on a better work process?
Does your $PYTHONPATH shell variable reference a relative path? If so, the relative path may be incorrect when you change to the new directory.
You can also diff the contents of the two directories to ensure that your versioned copy is a duplicate of the original.
Check if your module has init.py
As George said check if module is on python path (import sys and print sys.path)

Py_Initialize fails - unable to load the file system codec

I am attempting to put together a simple c++ test project that uses an embedded python 3.2 interpreter. The project builds fine but Py_Initialize raises a fatal error:
Fatal Python error: Py_Initialize: unable to load the file system codec
LookupError: no codec search functions registered: can't find encoding
Minimal code:
#include <Python.h>
int main (int, char**)
{
Py_Initialize ();
Py_Finalize ();
return 0;
}
The OS is 32bit Vista.
The python version used is a python 3.2 debug build, built from sources using VC++ 10.
The python_d.exe file from the same build runs without any problems.
Could someone explain the problem and how to fix it? My own google-fu fails me.
EDIT 1
After going through the python source code I've found that, as the error says, no codec search functions have been registered. Both codec_register and PyCodec_Register are as they should be. It's just that nowhere in the code are any of these functions called.
I don't really know what this means as I still have no idea when and from where these functions should have been called. The code that raises the error is entirely missing from the source of my other python build (3.1.3).
EDIT 2
Answered my own question below.
Check the PYTHONPATH and PYTHONHOME environment variables and make sure they don't point to Python 2.x.
http://bugs.python.org/issue11288
Parts of this have been mentioned before, but in a nutshell this is what worked for my environment where I have multiple Python installs and my global OS environment set-up to point to a different install than the one I attempt to work with when encountering the problem.
Make sure your (local or global) environment is fully set-up to point to the install you aim to work with, e.g. you have two (or more) installs of, let's say a python27 and python33 (sorry these are windows paths but the following should be valid for equivalent UNIX-style paths just as well, please let me know about anything I'm missing here (probably the DLLs path might differ)):
C:\python27_x86
C:\python33_x64
Now, if you intend to work with your python33 install but your global environment is pointing to python27, make sure you update your environment as such (while PATH and PYTHONHOME may be optional (e.g. if you temporarily work in a local shell)):
PATH="C:\python33_x64;%PATH%"
PYTHONPATH="C:\python33_x64\DLLs;C:\python33_x64\Lib;C:\python33_x64\Lib\site-packages"
PYTHONHOME=C:\python33_x64
Note, that you might need/want to append any other library paths to your PYTHONPATH if required by your development environment, but having your DLLs, Lib and site-packages properly set-up is of prime importance.
Hope this helps.
The core reason is quite simple: Python does not find its modules directory, so it can of course not load encodings, too
Python doc on embedding says "Py_Initialize() calculates the module search path based upon its best guess" ... "In particular, it looks for a directory named lib/pythonX.Y"
Yet, if the modules are installed in (just) lib - relative to the python binary - above guess is wrong.
Although docs says that PYTHONHOME and PYTHONPATH are regarded, we observed that this was not the case; their actual presence or content was completely irrelevant.
The only thing that had an effect was a call to Py_SetPath() with e.g. [path-to]\lib as argument before Py_Initialize().
Sure this is only an option for an embedding scenario where one has direct access and control over the code; with a ready-made solution, special steps may be necessary to solve the issue.
Ran into the same thing trying to install brew's python3 under Mac OS! The issue here is that in Mac OS, homebrew puts the "real" python a whole layer deeper than you think. You would think from the homebrew output that
$ echo $PYTHONHOME
/usr/local/Cellar/python3/3.6.2/
$ echo $PYTHONPATH
/usr/local/Cellar/python3/3.6.2/bin
would be correct, but invoking $PYTHONPATH/python3 immediately crashes with the abort 6 "can't find encodings." This is because although that $PYTHONHOME looks like a complete installation, having a bin, lib etc, it is NOT the actual Python, which is in a Mac OS "Framework". Do this:
PYTHONHOME=/usr/local/Cellar/python3/3.x.y/Frameworks/Python.framework/Versions/3.x
PYTHONPATH=$PYTHONHOME/bin
(substituting version numbers as appropriate) and it will work fine.
From python3k, the startup need the encodings module, which can be found in PYTHONHOME\Lib directory.
In fact, the API Py_Initialize () do the init and import the encodings module.
Make sure PYTHONHOME\Lib is in sys.path and check the encodings module is there.
I had this issue with python 3.5, anaconda 3, windows 7 32 bit. I solved it by moving my pythonX.lib and pythonX.dll files into my working directory and calling
Py_SetPythonHome(L"C:\\Path\\To\\My\\Python\\Installation");
before initialize so that it could find the headers that it needed, where my path was to "...\Anaconda3\". The extra step of calling Py_SetPythonHome was required for me or else I'd end up getting other strange errors where python import files.
I just ran into the exact same problem (same Python version, OS, code, etc).
You just have to copy Python's Lib/ directory in your program's working directory ( on VC it's the directory where the .vcproj is )
There appears to be something going wrong with the release build either failing to include the appropriate codecs or else misidentifying the codec to use for system APIs. Since the python_d executable is working, what does that return for os.getfsencoding()? (Use the C API to call that between your Initialize/Finalize calls)
I had the same issue and found this question. However from the answers here I was not able to solve my problem. I started debugging the cpython code and thought that I might be discovered a bug. Therefore I opened a issue on the python issue tracker.
My mistake was that I did not understand that Py_SetPath clears all inferred paths.
So one needs to set all paths when calling this function.
Link to the issue conversation
For completion I also copied the most important part of the conversation below.
My original issue text
I compiled the source of CPython 3.7.3 myself on Windows with Visual Studio 2017 together with some packages like e.g numpy. When I start the Python Interpreter I am able to import and use numpy. However when I am running the same script via the C-API I get an ModuleNotFoundError.
So the first thing I did, was to check if numpy is in my site-packages directory and indeed there is a folder named numpy-1.16.2-py3.7-win-amd64.egg. (Makes sense because the python interpreter can find numpy)
The next thing I did was to get some information about the sys.path variable created when running the script via the C-API.
#### sys.path content ####
C:\Work\build\product\python37.zip
C:\Work\build\product\DLLs
C:\Work\build\product\lib
C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\2017\PROFESSIONAL\COMMON7\IDE\EXTENSIONS\TESTPLATFORM
C:\Users\rvq\AppData\Roaming\Python\Python37\site-packages
Examining the content of sys.path I noticed two things.
C:\Work\build\product\python37.zip has the correct path 'C:\Work\build\product\'. There was just no zip file. All my files and directory were unpacked. So I zipped the files to an archive named python37.zip and this resolved the import error.
C:\Users\rvq\AppData\Roaming\Python\Python37\site-packages is wrong it should be C:\Work\build\product\Lib\site-packages but I dont know how this wrong path is created.
The next thing I tried was to use Py_SetPath(L"C:/Work/build/product/Lib/site-packages") before calling Py_Initialize(). This led to
Fatal Python Error 'unable to load the file system encoding'
ModuleNotFoundError: No module named 'encodings'
I created a minimal c++ project with exact these two calls and started to debug Cpython.
int main()
{
Py_SetPath(L"C:/Work/build/product/Lib/site-packages");
Py_Initialize();
}
I tracked the call of Py_Initialize() down to the call of
static int
zipimport_zipimporter___init___impl(ZipImporter *self, PyObject *path)
inside of zipimport.c
The comment above this function states the following:
Create a new zipimporter instance. 'archivepath' must be a path-like
object to a zipfile, or to a specific path inside a zipfile. For
example, it can be '/tmp/myimport.zip', or
'/tmp/myimport.zip/mydirectory', if mydirectory is a valid directory
inside the archive. 'ZipImportError' is raised if 'archivepath'
doesn't point to a valid Zip archive. The 'archive' attribute of the
zipimporter object contains the name of the zipfile targeted.
So for me it seems that the C-API expects the path set with Py_SetPath to be a path to a zipfile. Is this expected behaviour or is it a bug?
If it is not a bug is there a way to changes this so that it can also detect directories?
PS: The ModuleNotFoundError did not occur for me when using Python 3.5.2+, which was the version I used in my project before. I also checked if I had set any PYTHONHOME or PYTHONPATH environment variables but I did not see one of them on my system.
Answer
This is probably a documentation failure more than anything else. We're in the middle of redesigning initialization though, so it's good timing to contribute this feedback.
The short answer is that you need to make sure Python can find the Lib/encodings directory, typically by putting the standard library in sys.path. Py_SetPath clears all inferred paths, so you need to specify all the places Python should look. (The rules for where Python looks automatically are complicated and vary by platform, which is something I'm keen to fix.)
Paths that don't exist are okay, and that's the zip file. You can choose to put the stdlib into a zip, and it will be found automatically if you name it the default path, but you can also leave it unzipped and reference the directory.
A full walk through on embedding is more than I'm prepared to type on my phone. Hopefully that's enough to get you going for now.
I had the problem and was tinkering with different solutions mentioned here. Since I was running my project from Visual Studio, apparently, I needed to set the environment path inside Visual Studio and not the system path.
Adding a simple PYTHONHOME=PATH\TO\PYTHON\DIR in the project solution\properties\environment solved the problem.
For me this happened when I updated Python 64 bit from 3.6.4 to 3.6.5. It threw some error like "unable to extract python.dll. Do you have permissions."
Pycharm also failed to load interpreter, even though I reloaded it in settings. Running python command gave same error, with and without administrator mode.
Reason
There was error in installation of Python, include folder in python installation directory C:\Users\USERNAME\AppData\Local\Programs\Python\Python36 was missing
Reinstalling Python also dint solve the issue.(Not removal and install)
Solution
Uninstall Python and Install of Python again.
Because running installer was just extracting same files excluding include folder
In my cases, for windows, if you have multiple python versions installed, if PYTHONPATH is pointing to one version the other ones didn't work. I found that if you just remove PYTHONPATH, they all work fine
For those working in Visual Studio simply add the include, Lib and libs directories to the Include Directories and Library Directories under
Projects Properties -> Configuration Properties > VC++ Directories :
For example I have Anaconda3 on my system and working with Visual Studio 2015 This is how the settings looks like (note the Include and Library directories) :
Edit:
As also pointed out by bossi setting PYTHONPATH in your user Environment Variables section seems necessary.
a sample input can be like this (in my case):
C:\Users\Master\Anaconda3\Lib;C:\Users\Master\Anaconda3\libs;C:\Users\Master\Anaconda3\Lib\site-packages;C:\Users\Master\Anaconda3\DLLs
is necessary it seems.
Also, you need to restart Visual Studio after you set up the PYTHONPATH in your user Environment Variables for the changes to take effect.
Also note that :
Make sure the PYTHONHOME environment variable is set to the Python
interpreter you want to use. The C++ projects in Visual Studio rely on
this variable to locate files such as python.h, which are used when
creating a Python extension.
So, for some reason the python dll fails to locate the encodings module. The python.exe executable apparently finds it because it has the expected relative path. Modifying the search path works.
The reason for all of this? Don't know but at least it works. I highly suspect a typo on my part somewhere, that's usually the reason for odd bugs it seems.

How to make XCode put required resources in "build" folder?

I am trying out lua script with C++ in Mac OS X. I was finding a way to make the program returning the current working directory. That's no problem with getcwd, but then I came one thing:
My foo.lua stays at its initial path only. When I compile program, it is not being copied over to the build/Debug directory. Sure, I can grab my script there, but that's just impractical. XCode or any IDE should carry resources to the build zone. XCode does this automatically with iPhone app, but this seems to be a different case. For this case, how to command XCode to put the respective resources in the build directories?
int main (int argc, char * const argv[]) {
...
...
luaL_dofile(luaVM,"/Users/yourNameHere/Desktop/LuaSandbox/LetsTryLua/foo.lua");
//typing the whole absolute path here is just ugly and impractical.
...
...
printf("working directory: %s", buffer);
//output is: working directory: /Users/yourNameHere/Desktop/LuaSandbox/LetsTryLua/build/Debug
...
...
Rather than hard code the path to your Lua script you may want to use the NSBundle API's to find it:
NSBundle * mainNSBundle = [NSBundle mainBundle];
NSString * luaFilePath = [mainNSBundle pathForResource:#"foo"
ofType:#"lua"
inDirectory:NULL
forLocalization:NULL];
luaL_dofile(luaVM,[luaFilePath UTF8String]);
This will find it in the bundle's folder (if you added the "Copy Bundle Resources" build step to your target as the above poster suggested.
Because you're using a .lua file as a resource, I suspect that isn't recognised as a standard resource type and hence it hasn't been automatically copied. You should be able to do this though by adding an extra Copy Bundle Resources build step to your target and then add your file to it in the project view.
If you're creating a command line tool that is not a bundle, then there's never going to be a good solution. If you're creating a regular app then the aforementioned solution will work, but you're going to have to stop assuming that your working directory is set to anything even remotely meaningful at any point in time and use the appropriate methods for finding resources stored within your bundle.