[ot-users] TR: OpenTurns inquiry

regis lebrun regis_anne.lebrun_dutfoy at yahoo.fr
Tue Jul 25 18:45:34 CEST 2017


Hi Phil,


First of all, thank you for using OpenTURNS. Here is my input concerning your questions:

1. It is very easy to flip/translate (and even scale) an univariate distribution in OpenTURNS using the arithmetic of random variables, see flip_distribution.py.

2. There is currently no way to truncate multivariate distributions in OpenTURNS, but a quick and dirty (ie mathematically correct but not optimized) way to get it is given in truncated_nd_distribution.py

3. I have no idea on what is going on. I added the relevant guys to the discussion, but keep in mind that Denis and Julien are on holidays and Sofiane has a terrible workload, so you may have to wait a little bit for their input

For this kind of questions, it is better to use the users mailing list, see http://openturns.org/mailman/listinfo/users to subscribe to the list.

Best regards,

Régis
De :Phil Fernandes [mailto:phil.fernandes at enbridge.com] 
Envoyé : mardi 25 juillet 2017 00:29
À : LEBRUN, Regis; barbier at imacs.polytechnique.fr
Objet : OpenTurns inquiry
 
Hello Regis, Denis,
 
I am an engineer with Enbridge Pipelines and we have recently begun using OpenTurns for reliability analysis of our infrastructure. So far I am finding it to be an excellent and very comprehensive software library – thank you for helping develop it. 
 
I have run into a few of issues when using OpenTurns and was wondering if you might be able to provide some help:
1.       Is there a way of mirroring skewed distributions, for example flipping a Weibull distribution so that instead of a lower limit it has an upper limit?
 
2.       Is it possible to truncate a multivariate kernel density distributions? We can truncate univariate parametric distributions using the syntax
truncdist = ot.TruncatedDistribution(mydist, lower, upper)
but is there something analogous for multivariate KDEs where we can define bounds for each dimension?
 
3.       There is a conflict between the Python library PyMC3 and Theano and OpenTurns. If Theano is imported first, OpenTurns fails to import with the following error
Traceback (most recent call last):
 
  File "<ipython-input-3-704e69d30dff>", line 1, in <module>
    import openturns as ot
 
  File "C:\Anaconda3\lib\site-packages\openturns\__init__.py", line 61, in <module>
    from .common import *
 
  File "C:\Anaconda3\lib\site-packages\openturns\common.py", line 20, in <module>
    _common = swig_import_helper()
 
  File "C:\Anaconda3\lib\site-packages\openturns\common.py", line 19, in swig_import_helper
    return importlib.import_module('_common')
 
  File "C:\Anaconda3\lib\importlib\__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
 
ModuleNotFoundError: No module named '_common'
 
If I reverse the import order (i.e., OpenTurns first, then PyMC3 or Theano), then PymC3/Theano fails to import with
                                Traceback (most recent call last):
 
  File "<ipython-input-2-e9f7838173a6>", line 5, in <module>
    import pymc3 as pm
 
  File "C:\Anaconda3\lib\site-packages\pymc3\__init__.py", line 5, in <module>
    from .distributions import *
 
  File "C:\Anaconda3\lib\site-packages\pymc3\distributions\__init__.py", line 1, in <module>
    from . import timeseries
 
  File "C:\Anaconda3\lib\site-packages\pymc3\distributions\timeseries.py", line 1, in <module>
    import theano.tensor as tt
 
  File "C:\Anaconda3\lib\site-packages\theano\__init__.py", line 80, in <module>
    from theano.scan_module import (scan, map, reduce, foldl, foldr, clone,
 
  File "C:\Anaconda3\lib\site-packages\theano\scan_module\__init__.py", line 41, in <module>
    from theano.scan_module import scan_opt
 
  File "C:\Anaconda3\lib\site-packages\theano\scan_module\scan_opt.py", line 60, in <module>
    from theano import tensor, scalar
 
  File "C:\Anaconda3\lib\site-packages\theano\tensor\__init__.py", line 9, in <module>
    from theano.tensor.subtensor import *
 
  File "C:\Anaconda3\lib\site-packages\theano\tensor\subtensor.py", line 26, in <module>
    import theano.gof.cutils  # needed to import cutils_ext
 
  File "C:\Anaconda3\lib\site-packages\theano\gof\cutils.py", line 320, in <module>
    compile_cutils()
 
  File "C:\Anaconda3\lib\site-packages\theano\gof\cutils.py", line 285, in compile_cutils
    preargs=args)
 
  File "C:\Anaconda3\lib\site-packages\theano\gof\cmodule.py", line 2325, in compile_str
    return dlimport(lib_filename)
 
  File "C:\Anaconda3\lib\site-packages\theano\gof\cmodule.py", line 302, in dlimport
    rval = __import__(module_name, {}, {}, [module_name])
 
ImportError: DLL load failed: The specified procedure could not be found.
 
Your help would be very much appreciated.
Thank you.
 
Phil Fernandes   P.Eng, MASc
Engineer, Reliability Assessment
—

ENBRIDGE PIPELINES INC.
TEL: 780-420-8210  |  FAX: 780-420-5234   
7045 Enbridge Centre, 10175 101 Street NW, Edmonton, AB, T5J 0H3

www.enbridge.com
Integrity. Safety. Respect.
 
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