name input_powerspec.txt after config file

src/config_file.hh

@@ -161,6 +161,10 @@ public:
       }
 
       items_[in_section + '/' + name] = value;
+
+      size_t lastindex = filename.find_last_of('.');
+      std::string config_basename = filename.substr(0, lastindex);
+      items_["meta/config_basename"] = config_basename;
     }
   }
 
@@ -288,6 +292,12 @@ public:
     return get_value_safe("", key, default_value);
   }
 
+  std::string get_path_relative_to_config(std::string const &filename) const {
+    std::string empty_string;
+    const std::string basename = get_value_safe("meta", "config_basename", empty_string);
+    return basename + "_" + filename;
+  }
+
   //! dumps all key-value pairs to a std::ostream
   void dump(std::ostream &out) {
     std::map<std::string, std::string>::const_iterator i = items_.begin();

src/convolution_kernel.cc

@@ -177,7 +177,7 @@ class kernel_k : public kernel
 		pnorm_ = ptf->cosmo_params_["pnorm"];
 		kfac_ = 2.0 * M_PI / boxlength_;
 		kmax_ = kfac_ / 2;
-		tfk_ = new TransferFunction_k(type_, ptf_, nspec_, pnorm_);
+		tfk_ = new TransferFunction_k(type_, ptf_, nspec_, pnorm_, cf);
 
 		cparam_.nx = 1;
 		cparam_.ny = 1;

src/transfer_function.hh

@@ -163,15 +163,15 @@ public:
 	double pnorm_, sqrtpnorm_;
 	static tf_type type_;
 
-	TransferFunction_k(tf_type type, transfer_function *tf, real_t nspec, real_t pnorm)
+	TransferFunction_k(tf_type type, transfer_function *tf, real_t nspec, real_t pnorm, config_file &cf)
 			: pnorm_(pnorm)
 	{
 		ptf_ = tf;
 		nspec_ = nspec;
 		sqrtpnorm_ = sqrt(pnorm_);
 		type_ = type;
 
-		std::string fname("input_powerspec.txt");
+		std::string fname(cf.get_path_relative_to_config("input_powerspec.txt"));
 		if (type == delta_cdm || type == delta_matter)
 		{
 			std::ofstream ofs(fname.c_str());