Add 2 new variants of read_persistence_diagram_from_file

git-svn-id: svn+ssh://scm.gforge.inria.fr/svnroot/gudhi/branches/read_persistence_from_file@2463 636b058d-ea47-450e-bf9e-a15bfbe3eedb

Former-commit-id: bd0dd2c981856c8e1a51b2b97ac10d9edd59f694

2 files changed, 82 insertions, 9 deletions

diff --git a/src/Bottleneck_distance/example/bottleneck_read_file_example.cpp b/src/Bottleneck_distance/example/bottleneck_read_file_example.cpp
index 74c8d1ab..e26edd26 100644
--- a/src/Bottleneck_distance/example/bottleneck_read_file_example.cpp
+++ b/src/Bottleneck_distance/example/bottleneck_read_file_example.cpp
@@ -45,10 +45,8 @@ int main(int argc, char** argv) {
         "should contain a birth-death pair per line. Third, optional parameter is an error bound on a bottleneck" <<
         " distance (set by default to zero). The program will now terminate \n";
   }
-  std::vector<Persistence_interval> diag1;
-  std::vector<Persistence_interval> diag2;
-  read_persistence_diagram_from_file(argv[1], std::back_inserter(diag1));
-  read_persistence_diagram_from_file(argv[2], std::back_inserter(diag2));
+  std::vector<std::pair<double, double>> diag1 = read_persistence_diagram_from_file(argv[1], -1);
+  std::vector<std::pair<double, double>> diag2 = read_persistence_diagram_from_file(argv[2], -1);
 
   double tolerance = 0.;
   if (argc == 4) {
diff --git a/src/common/include/gudhi/reader_utils.h b/src/common/include/gudhi/reader_utils.h
index 019a3db2..7b371afc 100644
--- a/src/common/include/gudhi/reader_utils.h
+++ b/src/common/include/gudhi/reader_utils.h
@@ -310,24 +310,99 @@ void read_persistence_diagram_from_file(std::string const& filename, OutputItera
 #ifdef DEBUG_TRACES
     std::cerr << "File \"" << filename << "\" does not exist.\n";
 #endif  // DEBUG_TRACES
+    return;
   }
 
-  std::string line;
   while (!in.eof()) {
+    std::string line;
     getline(in, line);
     if (line.length() != 0 && line[0] != '#') {
       double numbers[4];
       int n = sscanf(line.c_str(), "%lf %lf %lf %lf", &numbers[0], &numbers[1], &numbers[2], &numbers[3]);
-      //int field = (n == 4 ? static_cast<int>(numbers[0]) : -1);
-      int dim = (n >= 3 ? static_cast<int>(numbers[n - 3]) : -1);
-      *out++ = std::make_tuple(dim, numbers[n - 2], numbers[n - 1]);
+      if (n >= 2) {
+        //int field = (n == 4 ? static_cast<int>(numbers[0]) : -1);
+        int dim = (n >= 3 ? static_cast<int>(numbers[n - 3]) : -1);
+        *out++ = std::make_tuple(dim, numbers[n - 2], numbers[n - 1]);
+      }
+    }
+  }
+
+  in.close();
+} // read_persistence_diagram_from_file
+
+/**
+Reads a file containing persistance intervals.
+Each line might contain 2, 3 or 4 values: [field] [dimension] birth death
+The return value is an `std::map[dim, std::vector[std::pair[birth, death]]]`
+where `dim` is an `int`, `birth` a `double`, and `death` a `double`.
+**/
+std::map<int, std::vector<std::pair<double, double>>> read_persistence_diagram_from_file(std::string const& filename) {
+
+  std::map<int, std::vector<std::pair<double, double>>> ret;
+
+  std::ifstream in;
+  in.open(filename);
+  if (!in.is_open()) {
 #ifdef DEBUG_TRACES
-      std::cerr << numbers[n - 2] << " - " << numbers[n - 1] << "\n";
+    std::cerr << "File \"" << filename << "\" does not exist.\n";
 #endif  // DEBUG_TRACES
+    return ret;
+  }
+
+  while (!in.eof()) {
+    std::string line;
+    getline(in, line);
+    if (line.length() != 0 && line[0] != '#') {
+      double numbers[4];
+      int n = sscanf(line.c_str(), "%lf %lf %lf %lf", &numbers[0], &numbers[1], &numbers[2], &numbers[3]);
+      if (n >= 2) {
+        int dim = (n >= 3 ? static_cast<int>(numbers[n - 3]) : -1);
+        ret[dim].push_back(std::make_pair(numbers[n - 2], numbers[n - 1]));
+      }
+    }
+  }
+
+  in.close();
+  return ret;
+} // read_persistence_diagram_from_file
+
+
+/**
+Reads a file containing persistance intervals.
+Each line might contain 2, 3 or 4 values: [field] [dimension] birth death
+If `only_this_dim` = -1, dimension is ignored and all lines are returned.
+If `only_this_dim` is >= 0, only the lines where dimension = `only_this_dim` 
+(or where dimension is not specified) are returned.
+The return value is an `std::vector[std::pair[birth, death]]`
+where `dim` is an `int`, `birth` a `double`, and `death` a `double`.
+**/
+std::vector<std::pair<double, double>> read_persistence_diagram_from_file(std::string const& filename, int only_this_dim) {
+
+  std::vector<std::pair<double, double>> ret;
+
+  std::ifstream in;
+  in.open(filename);
+  if (!in.is_open()) {
+#ifdef DEBUG_TRACES
+    std::cerr << "File \"" << filename << "\" does not exist.\n";
+#endif  // DEBUG_TRACES
+    return ret;
+  }
+
+  while (!in.eof()) {
+    std::string line;
+    getline(in, line);
+    if (line.length() != 0 && line[0] != '#') {
+      double numbers[4];
+      int n = sscanf(line.c_str(), "%lf %lf %lf %lf", &numbers[0], &numbers[1], &numbers[2], &numbers[3]);
+      int dim = (n >= 3 ? static_cast<int>(numbers[n - 3]) : -1);
+      if (n >= 2 && (only_this_dim == -1 || dim == only_this_dim))
+        ret.push_back(std::make_pair(numbers[n - 2], numbers[n - 1]));
     }
   }
 
   in.close();
+  return ret;
 } // read_persistence_diagram_from_file
 
 #endif  // READER_UTILS_H_