what is x,t and y variables in this code?

Asked by sankari senthil

sankari senthil (view profile)

on 1 Feb 2017
Latest activity Commented on by Walter Roberson

Walter Roberson (view profile)

on 15 Sep 2019
[x,t] = simplefit_dataset;
net = feedforwardnet(10);
net = train(net,x,t);
view(net)
y = net(x);
perf = perform(net,y,t)

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Answer by Walter Roberson

Walter Roberson (view profile)

on 1 Feb 2017

x is the data. t is the class information.
y is the result of running prediction using the input data. When the prediction for an input does not match the known target for the input then the Neural Net is not as good is it could be.

Answer by Greg Heath

Greg Heath (view profile)

on 1 Feb 2017

x is the input matrix with N I-dimensional input columns
t is the output target matrix with N O-dimensional output target columns
vart1 = mean(var(t',1)) is the mean target variance
y is the output matrix with N O-dimensional output columns
e = t - y is the error matrix
NMSE = mse(e)/vart1 is the normalized output mean-squared-error
I prefer NMSE < 0.01 as a goal for regression and pattern-recognition,
NMSEo < 0.001 as a goal for open-loop time-series and
NMSEc < 0.01 as a goal for closed-loop time-series
Hope this helps.
Thank you for formally accepting my answer
Greg

Sadiq Akbar (view profile)

on 11 Sep 2019

[x,t] = simplefit_dataset;
Using this how can I enter my own inputs and traget data. e.g. if my input=[1; 2; 3; 4; 5]; and my target=[1 2 3 4;2 4 6 8;3 6 9 12;4 8 12 16;5 10 15 20]; Now WhenI eneter my this data via command window and enter these commands also i.e.
input=[1; 2; 3; 4; 5];
target=[1 2 3 4;2 4 6 8;3 6 9 12;4 8 12 16;5 10 15 20];
net = fitnet(10);
view(net)
net = train(net,x,yes);
view(net)
yes = net(x);
perf = perform(net,yes,t)
net = fitnet(10,'trainbr');
net = train(net,x,t);
yes = net(x);
perf = perform(net,yes,t)
I get this error:
RefFitNetExample
Undefined function or variable 'x'.
Error in RefFitNetExample (line 19)
net = train(net,x,yes);
So how to tacke this problem.

Walter Roberson

Walter Roberson (view profile)

on 11 Sep 2019
net = train(net, input, target);
Caution: it is... unusual... to have your target data wider than your input data, especially when your input is vector.