diff --git a/doc/tests/analytic_tests.tex b/doc/tests/analytic_tests.tex
index bdc1c7004e..b2b42f6c57 100644
--- a/doc/tests/analytic_tests.tex
+++ b/doc/tests/analytic_tests.tex
@@ -303,6 +303,7 @@
\input{projectile.tex}
\input{attenuate.tex}
\input{tensor_poly.tex}
+\input{gamma_scgpc.tex}
\input{sobol_sens.tex}
\input{rims.tex}
\input{parabolas.tex}
diff --git a/doc/tests/gamma_scgpc.tex b/doc/tests/gamma_scgpc.tex
new file mode 100644
index 0000000000..803d47d3d9
--- /dev/null
+++ b/doc/tests/gamma_scgpc.tex
@@ -0,0 +1,58 @@
+\section{Stochastic Collocation with Gamma Distribution}
+Associated external model: \texttt{poly\_scgpc\_gamma.py}
+
+Recall that the \textit{Gamma} distribution has the probability density function
+\begin{align}
+ f(x) = \frac{x^{\alpha-1}e^{-x/\beta}}{\beta^\alpha\Gamma\left(\alpha\right)}, \alpha > 0, \beta > 0
+\end{align}
+
+The following two polynomials are used to compute the analytic statistical moments:
+\textit{Gamma} distribution:
+\begin{align}
+ u_1(x, y) = x + y \\
+ u_2(x, y) = x^2 + y^2
+\end{align}
+where $x$ and $y$ are two mutually independent \textit{Gamma} variates, i.e.
+\begin{align}
+ x \thicksim \Gamma\left(\alpha_{1},\beta_{1}\right) \notag \\
+ y \thicksim \Gamma\left(\alpha_{2},\beta_{2}\right) \notag
+\end{align}
+
+\subsection{Mean and Variance}
+The first two statistical moments of $u_1(x,y)$ and $u_2{x,y}$ are:
+\begin{align}
+ \expv{u_1(x,y)} &= \int_{0}^\infty dxdyP\left(x,y\right)u_1\left(x,y\right), \notag \\
+ &= \int_{0}^\infty dxdy \Gamma\left(\alpha_{1},\beta_{1}\right) \Gamma\left(\alpha_{2},\beta_{2}\right) u_1\left(x,y\right), \notag \\
+ &= \frac{\alpha_{1}}{\beta_{1}} + \frac{\alpha_{2}}{\beta_{2}}
+\end{align}
+\begin{align}
+ \expv{u_2(x,y)} &= \int_{0}^\infty dxdyP\left(x,y\right)u_2\left(x,y\right), \notag \\
+ &= \int_{0}^\infty dxdy \Gamma\left(\alpha_{1},\beta_{1}\right) \Gamma\left(\alpha_{2},\beta_{2}\right) u_2\left(x,y\right), \notag \\
+ &= \frac{\left(\alpha_{1} + 1\right)\alpha_1}{\beta_{1}^2} + \frac{\left(\alpha_{2}+1\right)\alpha_2}{\beta_{2}^2}
+\end{align}
+
+\begin{align}
+ \text{var}[u_1(x,y)] &= \int_{0}^\infty dxdyP\left(x,y\right)\left[u_1\left(x,y\right) - \expv{u_1(x,y)}\right]^2, \notag \\
+ &= \frac{\alpha_{1}}{\beta_{1}^2} + \frac{\alpha_{2}}{\beta_{2}^2}
+\end{align}
+\begin{align}
+ \text{var}[u_2(x,y)] &= \int_{0}^\infty dxdyP\left(x,y\right)\left[u_2\left(x,y\right) - \expv{u_2(x,y)}\right]^2, \notag \\
+ &= \frac{\left(4\alpha_{1} + 6.0\right)\left(\alpha_{1} + 1\right)\alpha_1}{\beta_{1}^4} + \frac{\left(4\alpha_{2} + 6.0\right)\left(\alpha_{2}+1\right)\alpha_2}{\beta_{2}^4}
+\end{align}
+
+\subsection{numeric values}
+Some numeric values for the mean and variance are listed below for given distributions:
+\begin{align}
+ x \thicksim \Gamma\left(11, 5\right) \notag \\
+ y \thicksim \Gamma\left(2, 0.8\right) \notag
+\end{align}
+\begin{table}[h!]
+ \centering
+ \begin{tabular}{c|c|c}
+ $Function$ & mean & variance \\ \hline
+ $u_1$ & 4.7 & 3.565 \\
+ $u_2$ & 14.655 & 215.638125 \\
+ \end{tabular}
+\end{table}
+
+
diff --git a/framework/Distributions.py b/framework/Distributions.py
index a46e6dccbe..704de4738f 100644
--- a/framework/Distributions.py
+++ b/framework/Distributions.py
@@ -877,7 +877,6 @@ def stdProbabilityNorm(self):
@ In, None, None
@ Out float, norm
"""
- #return self.beta**self.alpha/factorial(self.alpha-1.)
return 1./factorial(self.alpha-1)
DistributionsCollection.addSub(Gamma.getInputSpecification())
diff --git a/framework/OrthoPolynomials.py b/framework/OrthoPolynomials.py
index ee3ce295aa..ef5e79c14e 100644
--- a/framework/OrthoPolynomials.py
+++ b/framework/OrthoPolynomials.py
@@ -377,7 +377,7 @@ def norm(self,order):
@ In, order, int, polynomial order to get norm of
@ Out, norm, float, value of poly norm
"""
- return np.sqrt(gamma(1.0+order)/gamma(1.0+order+self.params[0]))
+ return np.sqrt(gamma(1.0+order)*gamma(1.0+self.params[0])/gamma(1.0+order+self.params[0]))
diff --git a/tests/framework/AnalyticModels/poly_scgpc_gamma.py b/tests/framework/AnalyticModels/poly_scgpc_gamma.py
new file mode 100644
index 0000000000..e5bc9b797b
--- /dev/null
+++ b/tests/framework/AnalyticModels/poly_scgpc_gamma.py
@@ -0,0 +1,30 @@
+# Copyright 2017 Battelle Energy Alliance, LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#***************************************
+#* Simple analytic test ExternalModule *
+#***************************************
+# This model tests the stochastic collocation with gamma distribution
+
+import numpy as np
+
+def eval(inp,exp):
+ return sum(n**exp for n in inp)
+
+def run(self,Input):
+ self.ans = eval((self.x1,self.x2),1.0)
+ self.ans2 = eval((self.x1,self.x2),2.0)
+
+#
+# This model has analytic mean and variance documented in raven/docs/tests
+#
diff --git a/tests/framework/Samplers/SparseGrid/gold/scgpc/dumpGamma.csv b/tests/framework/Samplers/SparseGrid/gold/scgpc/dumpGamma.csv
new file mode 100644
index 0000000000..4dabeb6688
--- /dev/null
+++ b/tests/framework/Samplers/SparseGrid/gold/scgpc/dumpGamma.csv
@@ -0,0 +1,10 @@
+x1,x2,ans,ans2
+1.42393039323,1.16977778441,2.59370817764,3.39595782966
+1.42393039323,4.13175911167,5.5556895049,19.0990111216
+1.42393039323,9.69846310393,11.1223934972,96.0877643431
+2.46509275174,1.16977778441,3.63487053615,7.44506233958
+2.46509275174,4.13175911167,6.59685186341,23.1481156315
+2.46509275174,9.69846310393,12.1635558557,100.136868853
+3.91097685502,1.16977778441,5.08075463943,16.6641200254
+3.91097685502,4.13175911167,8.04273596669,32.3671733174
+3.91097685502,9.69846310393,13.609439959,109.355926539
diff --git a/tests/framework/Samplers/SparseGrid/gold/scgpc/dumpromGamma.csv b/tests/framework/Samplers/SparseGrid/gold/scgpc/dumpromGamma.csv
new file mode 100644
index 0000000000..4dabeb6688
--- /dev/null
+++ b/tests/framework/Samplers/SparseGrid/gold/scgpc/dumpromGamma.csv
@@ -0,0 +1,10 @@
+x1,x2,ans,ans2
+1.42393039323,1.16977778441,2.59370817764,3.39595782966
+1.42393039323,4.13175911167,5.5556895049,19.0990111216
+1.42393039323,9.69846310393,11.1223934972,96.0877643431
+2.46509275174,1.16977778441,3.63487053615,7.44506233958
+2.46509275174,4.13175911167,6.59685186341,23.1481156315
+2.46509275174,9.69846310393,12.1635558557,100.136868853
+3.91097685502,1.16977778441,5.08075463943,16.6641200254
+3.91097685502,4.13175911167,8.04273596669,32.3671733174
+3.91097685502,9.69846310393,13.609439959,109.355926539
diff --git a/tests/framework/Samplers/SparseGrid/gold/scgpc/dumpromGammaXml.xml b/tests/framework/Samplers/SparseGrid/gold/scgpc/dumpromGammaXml.xml
new file mode 100644
index 0000000000..75fc30c68f
--- /dev/null
+++ b/tests/framework/Samplers/SparseGrid/gold/scgpc/dumpromGammaXml.xml
@@ -0,0 +1,71 @@
+
+ GAUSSgpcROM(ans-ans2)
+
+
+ 4.7
+ 4.7
+ 3.565
+ 9
+
+ x1,x2
+ <_0_0_>4.7
+ <_0_1_>-1.76776695297
+ <_0_2_>2.35794922682e-15
+ <_1_0_>-0.663324958071
+ <_1_1_>6.4161883723e-17
+ <_1_2_>-3.52890360476e-16
+ <_2_0_>2.41409087508e-15
+ <_2_1_>-7.37861662814e-16
+ <_2_2_>6.4161883723e-17
+
+
+ 3.125
+ 0.44
+ 6.77204934613e-31
+
+
+ 0.876577840112
+ 0.123422159888
+ 1.89959308447e-31
+
+
+ 0.876577840112
+ 0.123422159888
+ 1.89959308447e-31
+
+
+
+
+ 14.655
+ 14.655
+ 215.638125
+ 9
+
+ x1,x2
+ <_0_0_>14.655
+ <_0_1_>-13.2582521472
+ <_0_2_>5.41265877365
+ <_1_0_>-3.18395979874
+ <_1_1_>1.02659013957e-15
+ <_1_2_>-1.53988520935e-15
+ <_2_0_>0.649923072371
+ <_2_1_>-5.90289330251e-15
+ <_2_2_>1.79653274424e-15
+
+
+ 205.078125
+ 10.56
+ 4.14968130146e-29
+
+
+ 0.951029067796
+ 0.0489709322041
+ 1.92437274321e-31
+
+
+ 0.951029067796
+ 0.0489709322041
+ 1.92437274321e-31
+
+
+
diff --git a/tests/framework/Samplers/SparseGrid/scgpc/polynomial.py b/tests/framework/Samplers/SparseGrid/scgpc/polynomial.py
index fd63334fa5..abbdbca507 100644
--- a/tests/framework/Samplers/SparseGrid/scgpc/polynomial.py
+++ b/tests/framework/Samplers/SparseGrid/scgpc/polynomial.py
@@ -15,7 +15,6 @@
def eval(inp,exp):
return sum(n**exp for n in inp)
- #return np.exp(-sum(inp)/len(inp))
def run(self,Input):
self.ans = eval((self.x1,self.x2),1.0)
diff --git a/tests/framework/Samplers/SparseGrid/test_scgpc_gamma_large_scale.xml b/tests/framework/Samplers/SparseGrid/test_scgpc_gamma_large_scale.xml
new file mode 100644
index 0000000000..882fb8ee44
--- /dev/null
+++ b/tests/framework/Samplers/SparseGrid/test_scgpc_gamma_large_scale.xml
@@ -0,0 +1,127 @@
+
+
+
+ scgpc
+ makeG,trainG,testG,printG,printRomG
+ 1
+
+
+ framework/Samplers/SparseGrid.gamma_large_scale
+ wangc
+ 2018-07-26
+ Samplers.SparseGridCollocation
+
+ This tests using SparseGridCollocation with gamma-distributed inputs with large scale parameters
+ to test the fix for issue #693
+
+
+ This test is analytic in mean and variance documented in the analytic tests.
+ Two models are used:
+ ans = x1 + x2 with analytic mean = 4.7, variance = 3.565
+ ans = x1**2 + x2**2 with analytic mean = 14.655, variance = 215.638125
+
+
+
+
+
+ 0
+ 11
+ 5
+
+
+ 0
+ 2
+ 0.8
+
+
+
+
+
+
+ GammaDist1
+
+
+ GammaDist2
+
+ GROM
+
+
+
+
+
+
+ x1,x2,ans,ans2
+
+
+ ans,ans2
+ x1,x2
+ TensorProduct
+ 2
+ x1
+ x2
+
+
+
+
+
+ dummyIN
+ polynomial
+ GSG
+
+
+
+ dummyIN
+ GROM
+ GSG
+
+
+
+ Gtests
+ GROM
+
+
+
+
+ Gsolns
+
+
+
+ Gsolns
+
+
+
+
+
+
+ x1,x2
+
+
+
+ x1,x2
+
+
+
+ x1,x2
+
+
+
+
+
+
+ csv
+ Gtests
+ input,output
+
+
+ csv
+ Gsolns
+ input,output
+
+
+ xml
+ GROM
+ all
+
+
+
+
diff --git a/tests/framework/Samplers/SparseGrid/tests b/tests/framework/Samplers/SparseGrid/tests
index e3a2e9a108..11c279b45f 100644
--- a/tests/framework/Samplers/SparseGrid/tests
+++ b/tests/framework/Samplers/SparseGrid/tests
@@ -63,6 +63,12 @@
UnorderedXml = 'scgpc/Gdumprom.xml'
csv = 'scgpc/Gdump.csv'
[../]
+ [./gamma_large_scale]
+ type = 'RavenFramework'
+ input = 'test_scgpc_gamma_large_scale.xml'
+ UnorderedXml = 'scgpc/dumpromGammaXml.xml'
+ csv = 'scgpc/dumpGamma.csv scgpc/dumpromGamma.csv'
+ [../]
[./beta]
type = 'RavenFramework'
input = 'test_scgpc_beta.xml'