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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-07-24 09:54:23 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-07-24 09:54:44 +0000 |
commit | 836b47cb7e99a977c5a23b059ca1d0b5065d310e (patch) | |
tree | 1604da8f482d02effa033c94a84be42bc0c848c3 /ml/dlib/examples/svm_pegasos_ex.cpp | |
parent | Releasing debian version 1.44.3-2. (diff) | |
download | netdata-836b47cb7e99a977c5a23b059ca1d0b5065d310e.tar.xz netdata-836b47cb7e99a977c5a23b059ca1d0b5065d310e.zip |
Merging upstream version 1.46.3.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'ml/dlib/examples/svm_pegasos_ex.cpp')
-rw-r--r-- | ml/dlib/examples/svm_pegasos_ex.cpp | 160 |
1 files changed, 0 insertions, 160 deletions
diff --git a/ml/dlib/examples/svm_pegasos_ex.cpp b/ml/dlib/examples/svm_pegasos_ex.cpp deleted file mode 100644 index e69b485fc..000000000 --- a/ml/dlib/examples/svm_pegasos_ex.cpp +++ /dev/null @@ -1,160 +0,0 @@ -// 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 dlib C++ library's - implementation of the pegasos algorithm for online training of support - vector machines. - - This example creates a simple binary classification problem and shows - you how to train a support vector machine 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 -1. - -*/ - - -#include <iostream> -#include <ctime> -#include <vector> -#include <dlib/svm.h> - -using namespace std; -using namespace dlib; - - -int main() -{ - // The svm functions use column vectors to contain a lot of the data on which they - // operate. So the first thing we do here is declare a convenient typedef. - - // 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. - // Or if you don't know how many features you want until runtime then you can put a 0 - // here and use the matrix.set_size() member function) - typedef matrix<double, 2, 1> sample_type; - - - // This is a typedef for the type of kernel we are going to use in this example. - // In this case I have selected the radial basis kernel that can operate on our - // 2D sample_type objects - typedef radial_basis_kernel<sample_type> kernel_type; - - - // Here we create an instance of the pegasos svm trainer object we will be using. - svm_pegasos<kernel_type> trainer; - // Here we setup the parameters to this object. See the dlib documentation for a - // description of what these parameters are. - trainer.set_lambda(0.00001); - trainer.set_kernel(kernel_type(0.005)); - - // Set the maximum number of support vectors we want the trainer object to use - // in representing the decision function it is going to learn. In general, - // supplying a bigger number here will only ever give you a more accurate - // answer. However, giving a smaller number will make the algorithm run - // faster and decision rules that involve fewer support vectors also take - // less time to evaluate. - trainer.set_max_num_sv(10); - - std::vector<sample_type> samples; - std::vector<double> labels; - - // make an instance of a sample matrix so we can use it below - sample_type sample, center; - - center = 20, 20; - - // Now let's go into a loop and randomly generate 1000 samples. - srand(time(0)); - for (int i = 0; i < 10000; ++i) - { - // Make a random sample vector. - sample = randm(2,1)*40 - center; - - // Now if that random vector is less than 10 units from the origin then it is in - // the +1 class. - if (length(sample) <= 10) - { - // let the svm_pegasos learn about this sample - trainer.train(sample,+1); - - // save this sample so we can use it with the batch training examples below - samples.push_back(sample); - labels.push_back(+1); - } - else - { - // let the svm_pegasos learn about this sample - trainer.train(sample,-1); - - // save this sample so we can use it with the batch training examples below - samples.push_back(sample); - labels.push_back(-1); - } - } - - // Now we have trained our SVM. Let's see how well it did. - // Each of these statements prints out the output of the SVM given a particular sample. - // The SVM outputs a number > 0 if a sample is predicted to be in the +1 class and < 0 - // if a sample is predicted to be in the -1 class. - - sample(0) = 3.123; - sample(1) = 4; - cout << "This is a +1 example, its SVM output is: " << trainer(sample) << endl; - - sample(0) = 13.123; - sample(1) = 9.3545; - cout << "This is a -1 example, its SVM output is: " << trainer(sample) << endl; - - sample(0) = 13.123; - sample(1) = 0; - cout << "This is a -1 example, its SVM output is: " << trainer(sample) << endl; - - - - - - // The previous part of this example program showed you how to perform online training - // with the pegasos algorithm. But it is often the case that you have a dataset and you - // just want to perform batch learning on that dataset and get the resulting decision - // function. To support this the dlib library provides functions for converting an online - // training object like svm_pegasos into a batch training object. - - // First let's clear out anything in the trainer object. - trainer.clear(); - - // Now to begin with, you might want to compute the cross validation score of a trainer object - // on your data. To do this you should use the batch_cached() function to convert the svm_pegasos object - // into a batch training object. Note that the second argument to batch_cached() is the minimum - // learning rate the trainer object must report for the batch_cached() function to consider training - // complete. So smaller values of this parameter cause training to take longer but may result - // in a more accurate solution. - // Here we perform 4-fold cross validation and print the results - cout << "cross validation: " << cross_validate_trainer(batch_cached(trainer,0.1), samples, labels, 4); - - // Here is an example of creating a decision function. Note that we have used the verbose_batch_cached() - // function instead of batch_cached() as above. They do the same things except verbose_batch_cached() will - // print status messages to standard output while training is under way. - decision_function<kernel_type> df = verbose_batch_cached(trainer,0.1).train(samples, labels); - - // At this point we have obtained a decision function from the above batch mode training. - // Now we can use it on some test samples exactly as we did above. - - sample(0) = 3.123; - sample(1) = 4; - cout << "This is a +1 example, its SVM output is: " << df(sample) << endl; - - sample(0) = 13.123; - sample(1) = 9.3545; - cout << "This is a -1 example, its SVM output is: " << df(sample) << endl; - - sample(0) = 13.123; - sample(1) = 0; - cout << "This is a -1 example, its SVM output is: " << df(sample) << endl; - - -} - |