Hello Alan;
I can see some misunderstandings of J that might not get fixed in a
single email. I have only a 50% confidence that I can even see what you
are trying to do. I'll ask some questions, phrased so that each question
is answerable with Yes:
0. Is it true that you see the following sentence as your 'main' sentence:
NetParams calcNetError Weights
1. do you see that the following sentence does the same thing?
(NIn; NHid; Nout; Data) calcNetError Weights
2. Do you see that your sentence:
calcNetError=: Input,desOutputs, Output, Error
defines 'calcNetError' as a noun?
3. Are you thinking that J works like FORTRAN, in that when you assign
an expression to a function name, you are setting the return value of
the function?
3a. Do you know that the return value of an explicitly defined J verb is
the value of last expression executed?
4. Do you see that, the way you have defined Data, it is the same as >Data
5. Do you see that 2{|:>Data is the same as 2({"1)Data? This gives you
the 2 column without having to do a transpose?
6. Does something like this work:
calcNetError=: 3 : 0
'NIn NHid Nout Data' =. x NB. The left argument is x; Do you
understand what is going on here with 'name name' =. expression?
Weights =. y NB. The right argument is y
Input =. 0 1 {"1 Data
desOutputs =. 2{"1 Data
Output =. Input propagate Weights NB. There may be some problems
here, as 'propogate' uses global names. That may need to wait for
another message.
Error =. +/ *: Output-desOutputs
Input;desOutputs;Output;Error NB. last expression, therefore the
return value. I changed the , to a ;
)
(NIn; NHid; Nout; Data) calcNetError Weights
(there will be those who complain that I'm doing someones homework I say
7 lines of J won't spoil him.)
7. Does this get you started?
Alan Mac Hugh wrote:
Hi I'm working on a assignment for college, I would e-mail my lecture,
but
the assignment due in on Monday at 12noon and I'm not sure if he
checks his
e-mail over the weekend. I have got the program working, but the
output is
not right.
When I type in
NetParams calcNetError Weights
I should just get the answer.
I know the answer there as when I type calcNetError, the answer is
the last
thing displayed.The propagate function is my lectures solution to a
previous
assignment all the rest is my own code.
Below is the code:
[code]
nProd =: +/ . * NB. dyad: returns inner product of x and y
sig =: [: %@:>: [: ^@:- ] NB. monad: returns sigmoid function of y
getIHW =: (2 2) $ (i. 4) { ] NB. monad: returns the input->hidden
weight matrix from y
getHOW =: (2 1) $ (4 + i. 2) { ] NB. monad: returns the
hidden->output
weight matrix from y
calcHiddenOut =:[: sig [ inProd getIHW NB. dyad: returns the hidden
unit
activations
NB. from input x to network with y weights
propagate =: [: sig calcHiddenOut inProd getHOW NB. dyad: returns the
output from the output unit
NB. from input x to a network with y weights
] Weights =: 10 5 15 30 1 1
10 5 15 30 1 1
NIn=: 2
NHid=:2
Nout=:1
Data=:0 1 1, 1 0 1, 0 0 0,: 1 1 0
NetParams=:NIn; NHid; Nout; Data
Input=: |: (0 1 { |: > Data)
desOutputs=:|: ( 2 { |: > Data)
Output=:Input propagate Weights
Error=:+/ *: Output-desOutputs
calcNetError=: Input,desOutputs, Output, Error
NetParams calcNetError Weights
[/code]
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