changed copy_rows_fromd_by_idx a bit to make it clearer

3 files changed, 10 insertions, 10 deletions

diff --git a/nerv/doc/nerv_matrix.md b/nerv/doc/nerv_matrix.md
index b915dee..dfd843d 100644
--- a/nerv/doc/nerv_matrix.md
+++ b/nerv/doc/nerv_matrix.md
@@ -63,10 +63,10 @@ Copy the content of a __CuMatrix__ `a` to __Matrix__ `self`, they should be of t
 Copy the content of the __Matrix__ `self` to a __MMatrix__ `a`.
 * __void Matrix.copy_tod(Matrix self, CuMatrix a)__  
 Copy the content of the __Matrix__ `self` to a __CuMatrix__ `a`.
-* __void Matrix.copy_rows_fromh_by_idx(Matrix self, MMatrix ma, MMatrixInt idx)__  
-`idx` should be a row vector. This function copy the rows of `ma` to `self` according to `idx`, in other words, it assigns `ma[idx[i]]` to `self[i]`.
-* __void Matrix.copy_rows_fromd_by_idx(Matrix self, CuMatrix b, CuMatrix idx)__  
-`idx` needs to a row vector matrix, it stacks the rows of index `idx` of the __CuMatrix__ `b` and copies to `self`.
+* __void Matrix.copy_rows_fromh_by_idx(Matrix self, MMatrix ma, MMatrixInt idx, int idx_begin)__  
+`idx` should be a row vector. This function copy the rows of `ma` to `self` according to `idx`, in other words, it assigns `ma[idx[i+idx_begin]]` to `self[i]`.
+* __void Matrix.copy_rows_fromd_by_idx(Matrix self, Matrix b, Matrix idx, int idx_begin)__  
+`idx` needs to a row vector matrix, it stacks the rows of index `idx` of the __CuMatrix__ `b` and copies to `self`. `idx_begin` is used as an offset in the `idx` index array.
 * __void Matrix.update_select_rows(Matrix self, Matrix err, Matrix idx, double alpha, double beta)__  
 Update selected rows of `self`, i.e. `self[idx[i]] = self[idx[i]] * (1 - beta * alpha) + alpha * err[i]`.
 * __void Matrix.add(Matrix self, Matrix ma, Matrix mb, Element_type alpha, Element_type beta)__  
diff --git a/nerv/lib/matrix/generic/cukernel.cu b/nerv/lib/matrix/generic/cukernel.cu
index 6c8e64a..d042d48 100644
--- a/nerv/lib/matrix/generic/cukernel.cu
+++ b/nerv/lib/matrix/generic/cukernel.cu
@@ -294,7 +294,7 @@ __global__ void cudak_(gen_col_idx)(MATRIX_ELEM *b,
 }
 
 __global__ void cudak_(copy_rows_by_idx)(const MATRIX_ELEM *a, MATRIX_ELEM *b,
-                                    const MATRIX_ELEM *idx, int b_begin,
+                                    const MATRIX_ELEM *idx,
                                     int nrow, int ncol, int stride) {
     int j = blockIdx.x * blockDim.x + threadIdx.x;
     int i = blockIdx.y * blockDim.y + threadIdx.y;
@@ -620,13 +620,13 @@ extern "C" {
     }
 
     void cudak_(cuda_copy_rows_by_idx)(const Matrix *a, Matrix *b,
-                                        const Matrix *idx, int b_begin) {
+                                        const Matrix *idx, int idx_begin) {
         dim3 threadsPerBlock(CUDA_THREADS_NN, 1);
         dim3 numBlocks(CEIL_DIV(b->ncol, threadsPerBlock.x), b->nrow);
         cudak_(copy_rows_by_idx)<<<numBlocks, threadsPerBlock>>> \
             (MATRIX_ELEM_PTR(a), MATRIX_ELEM_PTR(b),
-            MATRIX_ELEM_PTR(idx) + b_begin,
-             b_begin, b->nrow, b->ncol, b->stride / sizeof(MATRIX_ELEM));
+            MATRIX_ELEM_PTR(idx) + idx_begin,
+            b->nrow, b->ncol, b->stride / sizeof(MATRIX_ELEM));
         cudaStreamSynchronize(0);
     }
 }
diff --git a/nerv/matrix/generic/cumatrix.c b/nerv/matrix/generic/cumatrix.c
index 623352e..f675149 100644
--- a/nerv/matrix/generic/cumatrix.c
+++ b/nerv/matrix/generic/cumatrix.c
@@ -247,8 +247,8 @@ static int nerv_matrix_(lua_copy_rows_fromd_by_idx)(lua_State *L) {
     const Matrix *b = luaT_checkudata(L, 2, nerv_matrix_(tname));
     const Matrix *idx = luaT_checkudata(L, 3, nerv_matrix_(tname));
     long nrow = a->nrow;
-    int b_begin = lua_gettop(L) > 3 ? luaL_checkinteger(L, 4) : 0;
-    nerv_matrix_(copy_rows_fromd_by_idx)(a, b, idx, b_begin, &status);
+    int idx_begin = lua_gettop(L) > 3 ? luaL_checkinteger(L, 4) : 0;
+    nerv_matrix_(copy_rows_fromd_by_idx)(a, b, idx, idx_begin, &status);
     NERV_LUA_CHECK_STATUS(L, status);
     return 0;
 }