# UQ\[py\]Lab (PCE display) **URL:** \ **Category:** UQ Discussion Forum\ **Tags:** pce, python, metamodeling\ **Created:** [January 11, 2024, 1:19pm UTC](https://uqworld.org/t/uq-py-lab-pce-display/2054 "2024-01-11T13:19:15Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Eilidh\_Radcliff](https://uqworld.org/user_avatar/uqworld.org/eilidh_radcliff/32/1221_2.png) [@Eilidh\_Radcliff](https://uqworld.org/u/Eilidh_Radcliff)\ **Post date:** [January 11, 2024, 1:19pm UTC](https://uqworld.org/t/uq-py-lab-pce-display/2054/1 "2024-01-11T13:19:15Z")
Hello, I’m currently working with UQ[py]Lab and have come across an issue. When I try to use `uq.display(myPCE)` to generate a visual representation of the coefficient distribution in myPCEmetamodel, it doesn’t seem to work. However, other functions like `uq.print(myPCE)` are functioning correctly after creating the metamodel. The error that I see is: ```matlab Traceback (most recent call last): line 72, in uq.display(myPCE) line 394, in display fig = self.make_fig(obj, name, type, **kwargs) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ line 403, in make_fig return helpers.display(obj, self, **kwargs) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ line 119, in display return display_util.PCE(obj) ^^^^^^^^^^^^^^^^^^^^^ line 358, in PCE Coefficients = np.array(Model['PCE']['Coefficients']) ~~~~~~~~~~~~ ^^^^^^^^^^^^^^^^ TypeError: list indices must be integers or slices, not str ``` Could you provide any suggestions on how to resolve this? Best regards, Eilidh ---
**Author:** ![styfen.schaer](https://uqworld.org/user_avatar/uqworld.org/styfen.schaer/32/849_2.png) [@styfen.schaer](https://uqworld.org/u/styfen.schaer)\ **Post date:** [January 11, 2024, 3:48pm UTC](https://uqworld.org/t/uq-py-lab-pce-display/2054/2 "2024-01-11T15:48:49Z")
Hi @Eilidh_Radcliff Thanks for reporting this. Can you please provide a minimal reproducible example? Best regards Styfen ---
**Author:** ![Eilidh\_Radcliff](https://uqworld.org/user_avatar/uqworld.org/eilidh_radcliff/32/1221_2.png) [@Eilidh\_Radcliff](https://uqworld.org/u/Eilidh_Radcliff)\ **Post date:** [January 12, 2024, 1:20pm UTC](https://uqworld.org/t/uq-py-lab-pce-display/2054/3 "2024-01-12T13:20:42Z")
Hi Styfen, Thank you for the fast response! I discovered this while experimenting with one of the examples from the documentation of UQLab. I will paste below: ```matlab from uqpylab import sessions, display_util import numpy as np import matplotlib.pyplot as plt import scipy.io mySession = sessions.cloud() ModelOpts = { 'Type': 'Model', 'ModelFun': 'simply_supported_beam_9points.model', 'isVectorized': 'true' } myModel = uq.createModel(ModelOpts) InputOpts = { 'Marginals': [ { 'Name': 'b', # beam width 'Type': 'Lognormal', 'Moments': [0.15, 0.0075] # (m) }, { 'Name': 'h', # beam height 'Type': 'Lognormal', 'Moments': [0.3, 0.015] # (m) }, { 'Name': 'L', # beam length 'Type': 'Lognormal', 'Moments': [5, 0.05] # (m) }, { 'Name': 'E', # Young's modulus 'Type': 'Lognormal', 'Moments': [3e10, 4.5e9] # (Pa) }, { 'Name': 'p', # uniform load 'Type': 'Lognormal', 'Moments': [1e4, 1e3] # (N/m) }] } myInput = uq.createInput(InputOpts) MetaOpts = { 'Type': 'Metamodel', 'MetaType': 'PCE' } MetaOpts['TruncOptions'] = {'qNorm': 0.75} MetaOpts['Degree'] = np.arange(2,11).tolist() MetaOpts['ExpDesign'] = { "NSamples" : 10, "Sampling" : "LHS" } myPCE = uq.createModel(MetaOpts) uq.print(myPCE) uq.display(myPCE) ``` ---
**Author:** ![styfen.schaer](https://uqworld.org/user_avatar/uqworld.org/styfen.schaer/32/849_2.png) [@styfen.schaer](https://uqworld.org/u/styfen.schaer)\ **Post date:** [January 12, 2024, 2:52pm UTC](https://uqworld.org/t/uq-py-lab-pce-display/2054/4 "2024-01-12T14:52:41Z")
Can you also provide the code for `simply_supported_beam_9points.model`? I tried it with a dummy function, but could not reproduce the error. Can you also tell me which Python version you are using and if you have installed UQ[py]Lab in a fresh Python environment? Can you also list the output of `pip list`? ---
**Author:** ![Eilidh\_Radcliff](https://uqworld.org/user_avatar/uqworld.org/eilidh_radcliff/32/1221_2.png) [@Eilidh\_Radcliff](https://uqworld.org/u/Eilidh_Radcliff)\ **Post date:** [January 14, 2024, 10:29am UTC](https://uqworld.org/t/uq-py-lab-pce-display/2054/5 "2024-01-14T10:29:46Z")
the code for simply\_supported\_beam\_9points: ```matlab import numpy as np def model(X): """calculates the deflection of a Simply Supported Beam on 9 equally-spaced points along the beam length. X refers to a sample of the input random variables: [b h L E p]. The points for which the deflection is calculated are xi = (1:9)/10*L. The vector Y contains the displacement at each of the 9 points. Parameters ---------- X: ndarray 5-column matrix x[:,0]: beam width (m) x[:,1]: beam height (m) x[:,2]: length (m) x[:,3]: Young modulus (Pa) x[:,4]: uniform load (N) Returns ------- ndarray Y[:,0]: deflection at xi=1/10*L ... Y[:,8]: deflection at xi=9/10*L """ X = np.array(X,ndmin=2) b = X[:, 0]; # beam width (m) h = X[:, 1]; # beam height (m) L = X[:, 2]; # Length (m) E = X[:, 3]; # Young modulus (Pa) p = X[:, 4]; # uniform load (N) # The beam is considered primatic, therefore: I = b* np.power(h,3) / 12; # the moment of intertia print('CALCULATING MODEL' ) Y = np.empty((X.shape[0],9)) for j in np.arange(0,9): xi = (j+1)/10*L Y[:,j] = -p*xi*(np.power(L,3)-2*np.power(xi,2)*L + xi**3)/(24*E*I); print('X type', type(X)) print('X shape', X.shape) print('b type', type(b)) print(type(h)) print(type(L)) print(type(E)) print(type(p)) print(type(I)) print('Y type',type(Y)) print('Y shape', Y.shape) return Y ``` My pip list is: Package Version * * * appdirs 1.4.4 asttokens 2.4.1 certifi 2023.11.17 charset-normalizer 3.3.2 colorama 0.4.6 comm 0.2.0 contourpy 1.2.0 cycler 0.12.1 decorator 5.1.1 executing 2.0.1 fonttools 4.47.0 idna 3.6 ipython 8.19.0 ipywidgets 8.1.1 jedi 0.19.1 jupyterlab-widgets 3.0.9 kiwisolver 1.4.5 matplotlib 3.8.2 matplotlib-inline 0.1.6 numpy 1.26.2 packaging 23.2 pandas 1.5.3 parso 0.8.3 Pillow 10.1.0 pip 22.3.1 plotly 5.18.0 prompt-toolkit 3.0.43 pure-eval 0.2.2 Pygments 2.17.2 pyparsing 3.1.1 python-dateutil 2.8.2 pytz 2023.3.post1 requests 2.31.0 scipy 1.11.4 setuptools 65.5.0 six 1.16.0 stack-data 0.6.3 tenacity 8.2.3 traitlets 5.14.0 uqpylab 0.95 urllib3 2.1.0 wcwidth 0.2.12 widgetsnbextension 4.0.9 I am using Python version: Python 3.11.3 I am working in a fresh venv. ---
**Author:** ![styfen.schaer](https://uqworld.org/user_avatar/uqworld.org/styfen.schaer/32/849_2.png) [@styfen.schaer](https://uqworld.org/u/styfen.schaer)\ **Post date:** [January 15, 2024, 7:51am UTC](https://uqworld.org/t/uq-py-lab-pce-display/2054/6 "2024-01-15T07:51:51Z")
Thank you for providing the code. I can now reproduce the error. It seems that `uq.display` is not yet implemented for multi-output PCE. Unfortunately, the error message is not really informative here. UQLab calculates a separate PCE for each output. So if `uq.display` is important for you, you can fix it for now using: ```python def display_ith(pce: dict, index: int) -> None: pce_ith = pce.copy() pce_ith["PCE"] = pce_ith["PCE"][index] uq.display(pce_ith) for i in range(len(myPCE["PCE"])): display_ith(myPCE, i) ``` Also note that `uq.print` only prints the first output. However, you should see this in the form of a warning message. Let us know if you have any further problems. ---
**Author:** ![Eilidh\_Radcliff](https://uqworld.org/user_avatar/uqworld.org/eilidh_radcliff/32/1221_2.png) [@Eilidh\_Radcliff](https://uqworld.org/u/Eilidh_Radcliff)\ **Post date:** [January 15, 2024, 10:41am UTC](https://uqworld.org/t/uq-py-lab-pce-display/2054/7 "2024-01-15T10:41:19Z")
Thank you - this resolves my error for this example too! 😄 When using the function uq.print, why is it only possible to print the first output?