add broadcasting

source/tensor/core/arithmetic/SumDim.cpp

@@ -17,6 +17,8 @@
 
 /*
  * $Created by: XIAO Tong (email: xiaotong@mail.neu.edu.cn) 2018-07-29
+ * &Updated by: XIAO Tong (email: xiaotong@mail.neu.edu.cn) 2018-12-26
+ * Add summation by broadcasting.
  */
 
 #include "Sum.h"
@@ -162,5 +164,48 @@ XTensor SumDim(const XTensor &a, const XTensor &b, int n, DTYPE beta)
     
     return c;
 }
+
+/* 
+tensor broadcast summation c = a + b * \beta where some of dimensions of b can be of size 1
+c = a + b * \beta
+
+>> a - a tensor
+>> b - another tensor that would be broadcasted
+>> c - the resulting tensor
+>> beta - the scaling factor
+*/
+void _SumBroadcast(const XTensor * a, const XTensor * b, XTensor * c, DTYPE beta = (DTYPE)1.0)
+{
+    CheckNTErrors(a->order == b->order, "Wrong tensor orders!");
+    CheckNTErrors(a->order == c->order, "Wrong tensor orders!");
+    CheckNTErrors(a->order > 0, "TODO!");
+
+    int stride = 1;
+    int strideNum = 1;
+    int blockNum = 1;
+    int count = 0;
+
+    for(int i = a->order - 1; i >= 0; i--){
+        if(a->GetDim(i) == b->GetDim(i)){
+            stride *= b->GetDim(i);
+            continue;
+        }
+        else if(b->GetDim(i) == 1){
+            strideNum *= b->GetDim(i);
+            if(i > 0 && b->GetDim(i - 1) == 1)
+                continue;
+        }
+        else{
+            ShowNTErrors("Wrong dimension size in broadcasting");
+        }
+
+        if(stride > 0){
+            blockNum = b->unitNum / (stride * strideNum);
+            stride *= strideNum;
+        }
+        else{
+        }
+    }
+}
     
 }

source/tensor/core/arithmetic/SumDim.cu

@@ -17,6 +17,8 @@
 
 /*
 * $Created by: XIAO Tong (email: xiaotong@mail.neu.edu.cn) 2018-07-29
+* &Updated by: XIAO Tong (email: xiaotong@mail.neu.edu.cn) 2018-12-26
+* Add summation by broadcasting.
 */
 
 #include "SumDim.cuh"
@@ -28,7 +30,7 @@ namespace nts { // namespace nts(NiuTrans.Tensor)
 
 /* 
 tensor summation of a tensor and a row vector
-c = a + b * \beta 
+c = a + b * \beta
 where a is a tensor and b is a row vector
 >> a - pointer to the data array of a
 >> b - pointer to the data array of b

source/tensor/core/arithmetic/SumDim.cuh

@@ -17,6 +17,8 @@
 
 /*
 * $Created by: XIAO Tong (email: xiaotong@mail.neu.edu.cn) 2018-07-29
+* &Updated by: XIAO Tong (email: xiaotong@mail.neu.edu.cn) 2018-12-26
+* Add summation by broadcasting.
 */
 
 #ifndef __SUMDIM_CUH__

source/tensor/core/arithmetic/SumDim.h

@@ -18,6 +18,9 @@
 /*
  * $Created by: XIAO Tong (email: xiaotong@mail.neu.edu.cn) 2018-07-29
  * It reached to 39 centigrade around 3:00 pm in Shenyang
+ * &Updated by: XIAO Tong (email: xiaotong@mail.neu.edu.cn) 2018-12-26
+ * Add summation by broadcasting.
+ * Four of my master students graduated. Good luck to them for their future work!
  */
 
 #ifndef __SUMDIM_H__
@@ -38,6 +41,9 @@ void _SumDim(XTensor * a, const XTensor * b, int n, DTYPE beta = (DTYPE)1.0);
 /* tensor summation c = a + b * \beta where the size of b is equal to the n-th dimension of a, 
    i.e., a is summed with b by broadcasting. We make a new tensor c to keep the result and return it */
 XTensor SumDim(const XTensor &a, const XTensor &b, int n, DTYPE beta = (DTYPE)1.0);
+
+/* tensor broadcast summation c = a + b * \beta where some of dimensions of b can be of size 1 */
+void _SumBroadcast(const XTensor * a, const XTensor * b, XTensor * c, DTYPE beta = (DTYPE)1.0);
     
 } // namespace nts(NiuTrans.Tensor)