Romeo Kienzer created SYSTEMML-1759:
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Summary: make UDFs callable from expressions
Key: SYSTEMML-1759
URL: https://issues.apache.org/jira/browse/SYSTEMML-1759
Project: SystemML
Issue Type: Improvement
Components: Parser
Affects Versions: SystemML 1.0
Environment: IBM DataScience Experience
Reporter: Romeo Kienzer
Priority: Minor
SystemML Parser stops with exeption:
only builtin functions allowed as part of
expression
But the following re-write could be automated during parsing
delta3 = -(Y-yHat) * sigmoidPrime(z3)
=>
smp = sigmoidPrime(z3)
delta3 = -(Y-yHat) * smp
Please consider the following code:
script = """
#
sigmoid = function(matrix[double] z) return (matrix[double] z) {
z = 1/(1+exp(-z))
}
sigmoidPrime = function(matrix[double] z) return (matrix[double] z) {
#Gradient of sigmoid
z = exp(-z)/(1+exp(-z))
}
X=matrix("3 5 5 1 10 2", rows=3, cols=2)
inputLayerSize = 2
outputLayerSize = 1
hiddenLayerSize = 3
W1 = rand(rows=inputLayerSize,cols=hiddenLayerSize)
W2 = rand(rows=hiddenLayerSize,cols=outputLayerSize)
feedForward = function (matrix[double] X,
matrix[double] W1,
matrix[double] W2) return (matrix[double]
z2,matrix[double] z3,matrix[double] Y) {
z2 = X %*% W1
a2 = sigmoid(z2)
z3 = (a2 %*% W2)
Y = sigmoid(z3)
}
gradient = function(matrix[double] X,
matrix[double] W1,
matrix[double] W2,
matrix[double] Y) return (matrix[double]
dJdW1,matrix[double] dJdW1) {
#Compute derivative with respect to W and W2 for a given X and y:
[z2,z3,Yhat] = feedForward(X,W1,W2)
delta3 = -(Y-yHat) * sigmoidPrime(z3)
dJdW2 = t(a2) %*% delta3
delta2 = (delta3 %*% t(W2))*sigmoidPrime(z2)
dJdW1 = t(X) %*% delta2
}
[z2,z3,Yhat]=feedForward(X,W1,W2)
nrx = nrow(X)
ncx = ncol(X)
nrw1 = nrow(W1)
ncw1 = ncol(W1)
"""
I'm getting a parser exeption saying that
Caused by: org.apache.sysml.parser.ParseException:
-------------------------------------------------------------- The following 2
parse issues were encountered:
1 [line 39:25] [Validation error] -> delta3 = -(Y-yHat) * sigmoidPrime(z3)
only builtin functions allowed as part of
expression
2 [line 42:32] [Validation error] -> delta2 = (delta3 %*% >
t(W2))*sigmoidPrime(z2) only builtin functions allowed as part of
expression
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