random_samplers_simplex.h and sample_simplex_main.cpp

examples/sample_simplex_main.cpp

@@ -0,0 +1,158 @@
+/*
+
+Sampling Uniformly from Unit or an Arbitrary Simplex given in V-representation.
+
+By Tolis Chalkis, N.K. Univ. Athens, Greece, 2017.
+
+###################################################
+--------------------- Main ------------------------
+###################################################
+
+This main file could help in execution for fuctions in random_samplers_simplex.h 
+
+------------ Sampling from Unit Simplex------------
+
+The command:
+./executable unit1 12 30000
+Will call SampleUnitSimplex01() for d=12 and 30000 random points requested.
+
+The command:
+./executable unit2 15 20000
+Will call SampleUnitSimplex02() for d=12 and 20000 random points requested.
+
+
+-------- Sampling from an Arbitrary Simplex-------
+
+For sampling from an arbitrary Simplex we have to give the vertices through a txt file.
+At the first line we should only declare the dimension d.
+In d+1 lines below we should declare the Points-vertices of the Simplex. For example the txt:
+
+***************
+* 3           *
+* 13 4 -27    *
+* 12 57 127   *
+* 12.3 -78 91 *
+* -7 89 21    *
+***************
+
+Is a valid txt for this main. 
+
+The command:
+./executable arb1 vertices.txt 100000
+Will call SampleArbSimplex01() for 100000 random points requested.
+
+The command:
+./executable arb2 vertices.txt 70000
+Will call SampleArbSimplex02() for 70000 random points requested.
+
+The command:
+./executable arb3 vertices.txt 6000
+Will call SampleArbSimplex03() for 6000 random points requested.
+
+
+------- We create a txt file that contains the random points (random_points.txt) --------
+
+The command -------> ./executable -help <------- Will print all the options.
+
+*/
+
+
+#include <fstream>
+#include <random_samplers_simplex.h>
+
+
+typedef double NT;
+typedef CGAL::Cartesian_d<NT> 	      Kernel; 
+typedef Kernel::Point_d Point_d;
+
+
+int main(int argc, char* argv[]){
+
+	std::vector<NT> newp;
+	std::vector<Point_d> v;
+	std::vector<Point_d> Points;
+	std::vector<Point_d>::iterator iter;
+	int dim,num,i;
+
+	if ( argc!=4 && argc!=2 ){
+		printf ("%d\n",argc);
+		std::cout<<"Wrong inputs! Use -help for help"<<std::endl;
+
+	}else if( !strcmp(argv[1],"-help") ){
+
+          std::cerr<<
+		"Usage:\n"<<
+		"-arb1 : Sampling uniformly from an arbitrary Simplex, using an Owen's algorithm Implementation\nCommand : ./exe -arb1 vertices.txt number_of_points\n\n"<<
+		"-arb2 : Sampling uniformly from an arbitrary Simplex, applying a linear transformation on Smith and Tromble's algorithm's random points in Unit Simplex\nCommand : ./exe -arb2 vertices.txt number_of_points\n\n"<<
+		"-arb3 : Sampling uniformly from an arbitrary Simplex, using a Grimme's algorithm Implementation\nCommand : ./exe -arb3 vertices.txt number_of_points\n\n"<<
+		"-unit1 : Sampling Uniformly from the Unit Simplex with Smith and Tromble's algorithm, using a Bloom filter variation to ensure a distinct choice of integers\nCommand : ./exe -unit1 dimension number_of_points\n\n"<<
+		"-unit2 : Sampling Uniformly from the Unit Simplex with Smith and Tromble's algorithm, using a hash function to ensure a distinct choice of integers \nCommand : ./exe -unit2 dimension number_of_points\n"<<
+	  std::endl;
+          exit(-1);
+
+	}else if( !strcmp(argv[1],"-arb1") || !strcmp(argv[1],"-arb2") || !strcmp(argv[1],"-arb3") ){
+
+		num=atoi(argv[3]);
+
+		std::ifstream inputFile;
+		std::string inputFileName = argv[2]; //reading the input txt file
+		inputFile.open(inputFileName.c_str()); //converting the input to a c-style string
+
+		std::istream_iterator< NT >  input_begin( inputFile );
+		std::istream_iterator< NT >  input_end;
+		for(std::istream_iterator< NT > it = input_begin; it != input_end; ++it){
+			newp.push_back(*it);
+		}
+		dim=newp[0];    // Get the dimension
+		int n=(newp.size()-1)/dim;  // Get the number of the points
+		v.reserve (n);
+		for(i=0;i<n;i++){
+			v.push_back(Point_d(dim,newp.begin()+i*dim+1,newp.begin()+i*dim+dim+1));  // Insert points to the vector
+		}
+		inputFile.close();
+
+		if( !strcmp(argv[1],"-arb1") ){
+			SampleArbSimplex01(v.begin(),v.end(),num,Points);
+		}else if( !strcmp(argv[1],"-arb2") ){
+			SampleArbSimplex02(v.begin(),v.end(),num,Points);
+		}else{
+			SampleArbSimplex03(v.begin(),v.end(),num,Points);
+		}
+
+		std::ofstream outputFile;
+		outputFile.open("random_points.txt");   // Create the txt file that contains the random points
+
+		for (iter=Points.begin(); iter!=Points.end(); iter++){
+			outputFile<< *iter <<std::endl;
+		}
+
+		outputFile.close();
+
+	}else if( !strcmp(argv[1],"-unit1") || !strcmp(argv[1],"-unit2") ){
+
+		num=atoi(argv[3]); dim=atoi(argv[2]);
+
+		if ( !strcmp(argv[1],"-unit1") ){
+			SampleUnitSimplex01(dim,num,Points);
+		}else{
+			SampleUnitSimplex02(dim,num,Points);
+		}
+
+		std::ofstream outputFile;
+		outputFile.open("random_points.txt");    // Create the txt file that contains the random points
+
+		for (iter=Points.begin(); iter!=Points.end(); iter++){
+			outputFile<< *iter <<std::endl;
+		}
+
+		outputFile.close();
+
+	}else{
+
+		std::cout<<"Wrong inputs! Use -help for help"<<std::endl;
+
+	}
+
+	return 0;
+
+}