mirror of https://github.com/davisking/dlib.git
87 lines
3.0 KiB
C++
87 lines
3.0 KiB
C++
// The contents of this file are in the public domain. See LICENSE_FOR_EXAMPLE_PROGRAMS.txt
|
|
/*
|
|
|
|
This is an example illustrating the use of the multilayer perceptron
|
|
from the dlib C++ Library.
|
|
|
|
This example creates a simple set of data to train on and shows
|
|
you how to train a mlp object on that data.
|
|
|
|
|
|
The data used in this example will be 2 dimensional data and will
|
|
come from a distribution where points with a distance less than 10
|
|
from the origin are labeled 1 and all other points are labeled
|
|
as 0.
|
|
|
|
*/
|
|
|
|
|
|
#include <iostream>
|
|
#include "dlib/mlp.h"
|
|
|
|
using namespace std;
|
|
using namespace dlib;
|
|
|
|
|
|
int main()
|
|
{
|
|
// The mlp takes column vectors as input and gives column vectors as output. The dlib::matrix
|
|
// object is used to represent the column vectors. So the first thing we do here is declare
|
|
// a convenient typedef for the matrix object we will be using.
|
|
|
|
// This typedef declares a matrix with 2 rows and 1 column. It will be the
|
|
// object that contains each of our 2 dimensional samples. (Note that if you wanted
|
|
// more than 2 features in this vector you can simply change the 2 to something else)
|
|
typedef matrix<double, 2, 1> sample_type;
|
|
|
|
|
|
// make an instance of a sample matrix so we can use it below
|
|
sample_type sample;
|
|
|
|
// Create a multi-layer perceptron network. This network has 2 nodes on the input layer
|
|
// (which means it takes column vectors of length 2 as input) and 5 nodes in the first
|
|
// hidden layer. Note that the other 4 variables in the mlp's constructor are left at
|
|
// their default values.
|
|
mlp::kernel_1a_c net(2,5);
|
|
|
|
// Now lets put some data into our sample and train on it. We do this
|
|
// by looping over 41*41 points and labeling them according to their
|
|
// distance from the origin.
|
|
for (int i = 0; i < 1000; ++i)
|
|
{
|
|
for (int r = -20; r <= 20; ++r)
|
|
{
|
|
for (int c = -20; c <= 20; ++c)
|
|
{
|
|
sample(0) = r;
|
|
sample(1) = c;
|
|
|
|
// if this point is less than 10 from the origin
|
|
if (sqrt((double)r*r + c*c) <= 10)
|
|
net.train(sample,1);
|
|
else
|
|
net.train(sample,0);
|
|
}
|
|
}
|
|
}
|
|
|
|
// Now we have trained our mlp. Lets see how well it did.
|
|
// Note that if you run this program multiple times you will get different results. This
|
|
// is because the mlp network is randomly initialized.
|
|
|
|
// each of these statements prints out the output of the network given a particular sample.
|
|
|
|
sample(0) = 3.123;
|
|
sample(1) = 4;
|
|
cout << "This sample should close to 1 and it is classified as a " << net(sample) << endl;
|
|
|
|
sample(0) = 13.123;
|
|
sample(1) = 9.3545;
|
|
cout << "This sample should close to 0 and it is classified as a " << net(sample) << endl;
|
|
|
|
sample(0) = 13.123;
|
|
sample(1) = 0;
|
|
cout << "This sample should close to 0 and it is classified as a " << net(sample) << endl;
|
|
}
|
|
|