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//Released under BSD-3 Cluse licsence
//How to run: root -b stackedsp.cpp
//or: c++ stackedsp.cpp -o stackedsp -O3 -lEtaler `root-config --cflags --ldflags --glibs` && ./stackedsp
//Assuming you have Etaler installed in /use/local/lib. Change this if you have it in other places
#pragma cling load("/usr/local/lib/")
#include <Etaler/Etaler.hpp>
#include <Etaler/Algorithms/SpatialPooler.hpp>
#include <Etaler/Encoders/GridCell1d.hpp>
#include <Etaler/Encoders/Scalar.hpp>
using namespace et;
#include <random>
constexpr intmax_t INPUT_SDR_SIZE = 2048;
#include <TGraph.h>
#include <TCanvas.h>
#include <TAxis.h>
void run_experiment(int num_sps)
//Make a stack of N SpatialPoolers
std::vector<SpatialPooler> sps;
for(int i=0;i<num_sps;i++) {
SpatialPooler sp(Shape({INPUT_SDR_SIZE}), Shape({INPUT_SDR_SIZE}));
//Encode a scalar using a 1D GridCell encoder. A ScalarEncoder does the same job.
auto encode = [](float v){return encoder::gridCell1d(v,128);};
//Like an RBM, inference on each layer, train it and use it's outout as the
//next layer's input
auto train = [&](auto x){for(auto& sp : sps) {auto y = sp.compute(x); sp.learn(x, y); x = y;}};
//Train the SP with random inputs
std::mt19937 rng;
std::uniform_real_distribution<float> dist;
for(size_t i=0;i<1000;i++) {
Tensor x = encode(dist(rng));
auto inference = [&](auto sdr) {Tensor x = sdr; for(auto& sp : sps) x = sp.compute(x); return x;};
//Calculathe the amount of overlapped bits from values 0~1 compared to 0.5
Tensor t = inference(encode(0.5));
std::vector<float> y;
std::vector<float> x;
for(float i=0;i<1;i+=0.01) {
int v = sum(t && inference(encode(i))).toHost<int>()[0];
//Now we are done with traning and generating the results. We plot the result
//Plot the resulting overlapped bits using ROOT's ploting capablity
auto c1 = std::make_unique<TCanvas>();
auto gr1 = std::make_unique<TGraph>((Int_t)x.size(),,;
//Set the textes
gr1->SetTitle(("Overlap cells with " + std::to_string(num_sps) + " SPs").c_str());
gr1->GetXaxis()->SetTitle("Encoded value");
gr1->GetYaxis()->SetTitle("Overlapped bits");
c1->SaveAs(("plot_" + std::to_string(num_sps) + ".png").c_str());
void stackedsp()
//C++17 type reduction is awesome
std::vector num_sps = {0, 1, 2, 4, 8, 16};
for(auto n : num_sps)
int main()
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