From f1cc8f8ee759743982988b9ec6dc406c8a96c4e2 Mon Sep 17 00:00:00 2001
From: Dongryeol Lee <drselee@gmail.com>
Date: Mon, 10 Sep 2007 21:09:45 +0000
Subject: [PATCH] Small bug fix in TransFarToFar: the order of the
 approximation was set to 0, but it really should have been set to the order
 of the translated expansion

---
 .../series_expansion/series_expansion.h       | 30 +++++++++++++++++--
 .../series_expansion/series_expansion_aux.h   | 21 -------------
 2 files changed, 28 insertions(+), 23 deletions(-)

diff --git a/fastlib/u/dongryel/series_expansion/series_expansion.h b/fastlib/u/dongryel/series_expansion/series_expansion.h
index b7356df73f..a0a7d4fc7d 100644
--- a/fastlib/u/dongryel/series_expansion/series_expansion.h
+++ b/fastlib/u/dongryel/series_expansion/series_expansion.h
@@ -445,6 +445,9 @@ template<typename TKernel>
 void SeriesExpansion<TKernel>::PrintDebug(const char *name, 
 					  FILE *stream) const {
   
+  int dim = sea_->get_dimension();
+  int total_num_coeffs = sea_->get_total_num_coeffs(order_);
+
   fprintf(stream, "----- SERIESEXPANSION %s ------\n", name);
   fprintf(stream, "Expansion type: %s\n", (expansion_type_ == FARFIELD) ?
 	  "FARFIELD":"LOCAL");
@@ -455,8 +458,29 @@ void SeriesExpansion<TKernel>::PrintDebug(const char *name,
   }
   fprintf(stream, "\n");
   
-  for (index_t i = 0; i < coeffs_.length(); i++) {
-    fprintf(stream, "%g ", coeffs_[i]);
+  fprintf(stream, "f(");
+  for(index_t d = 0; d < dim; d++) {
+    fprintf(stream, "x_%d", d);
+    if(d < dim - 1)
+      fprintf(stream, ",");
+  }
+  fprintf(stream, ") = ");
+
+  for (index_t i = 0; i < total_num_coeffs; i++) {
+    ArrayList<int> mapping = sea_->get_multiindex(i);
+    if(expansion_type_ == FARFIELD) {
+      fprintf(stream, "%g", coeffs_[i]);
+      
+      for(index_t d = 0; d < dim; d++) {
+	fprintf(stream, "(x_%d - (%g))^%d", d, center_[d], mapping[d]);
+      }
+    }
+    else {
+      fprintf(stream, "%g ", coeffs_[i]);
+    }
+    if(i < total_num_coeffs - 1) {
+      fprintf(stream, " + ");
+    }
   }
   fprintf(stream, "\n");
 }
@@ -486,6 +510,8 @@ void SeriesExpansion<TKernel>::TransFarToFar(const SeriesExpansion &se) {
   // no coefficients can be translated
   if(order == 0)
     return;
+  else
+    order_ = order;
   
   // the first order (the sum of the weights) stays constant regardless
   // of the location of the center.
diff --git a/fastlib/u/dongryel/series_expansion/series_expansion_aux.h b/fastlib/u/dongryel/series_expansion/series_expansion_aux.h
index 7733904126..86c6706634 100644
--- a/fastlib/u/dongryel/series_expansion/series_expansion_aux.h
+++ b/fastlib/u/dongryel/series_expansion/series_expansion_aux.h
@@ -31,27 +31,6 @@ class SeriesExpansionAux {
   /** row index is for n, column index is for k */
   Matrix n_choose_k_;
 
-  /** compute n choose k: this might be moved later to FastLib core... */
-  int nchoosek(int n, int k) {
-    int n_k = n - k;
-    int nchsk = 1;
-    int i;
-    
-    if(k > n)
-      return 0;
-    
-    if(k < n_k) {
-      k = n_k;
-      n_k = n - k;
-    }
-    
-    for(i = 1; i <= n_k; i++) {
-      nchsk *= (++k);
-      nchsk /= i;
-    }
-    return nchsk;
-  }
-  
  public:
 
   // construtor/destructor