add docstrings

Author: victorsndvg

src/SparseMatrixCSR.jl

@@ -1,4 +1,11 @@
 
+"""
+    struct SparseMatrixCSR{T,Ti<:Integer} <: AbstractSparseMatrix{T,Ti}
+
+Matrix type for storing sparse matrices in the
+Compressed Sparse Row format. The standard way
+of constructing SparseMatrixCSR is through the [`sparsecsr`](@ref) function.
+"""
 struct SparseMatrixCSR{T,Ti<:Integer} <: AbstractSparseMatrix{T,Ti}
     transpose :: SparseMatrixCSC{T,Ti}
 end
@@ -8,15 +15,61 @@ show(io::IO, A::SparseMatrixCSR) = show(io, A.transpose)
 size(A::SparseMatrixCSR) = (A.transpose.n, A.transpose.m)
 getindex(A::SparseMatrixCSR, x::Integer, y::Integer) = getindex(A.transpose,y,x)
 
-nnz(S::SparseMatrixCSR)         = nnz(S.transpose)
+"""
+    nnz(S::SparseMatrixCSR)
+
+Returns the number of stored (filled) elements in a sparse array.
+"""
+nnz(S::SparseMatrixCSR) = nnz(S.transpose)
+
+"""
+    count(pred, S::SparseMatrixCSR) -> Integer
+
+Count the number of elements in S for which predicate pred returns true. 
+"""
 count(pred, S::SparseMatrixCSR) = count(pred, S.transpose)
 
+"""
+    nonzeros(S::SparseMatrixCSR)
+
+Return a vector of the structural nonzero values in sparse array S. 
+This includes zeros that are explicitly stored in the sparse array. 
+The returned vector points directly to the internal nonzero storage of A, 
+and any modifications to the returned vector will mutate A as well.
+"""
 nonzeros(S::SparseMatrixCSR) = S.transpose.nzval
 
+"""
+    nzrange(S::SparseMatrixCSR, row::Integer)
+
+Return the range of indices to the structural nonzero values of a 
+sparse matrix row. 
+"""
 nzrange(S::SparseMatrixCSR, row::Integer) = nzrange(S.transpose, row)
 
+"""
+    findnz(S::SparseMatrixCSR)
+
+Return a tuple (I, J, V) where I and J are the row and column indices 
+of the stored ("structurally non-zero") values in sparse matrix A, 
+and V is a vector of the values.
+"""
 findnz(S::SparseMatrixCSR) = findnz(S.transpose)
 
+"""
+    sparsecsr(I, J, V, [m, n, combine])
+
+Create a sparse matrix S of dimensions m x n such that S[I[k], J[k]] = V[k]. 
+The combine function is used to combine duplicates. 
+If m and n are not specified, they are set to 
+maximum(I) and maximum(J) respectively. 
+If the combine function is not supplied, combine defaults to + 
+unless the elements of V are Booleans in which case combine defaults to |. 
+All elements of I must satisfy 1 <= I[k] <= m, 
+and all elements of J must satisfy 1 <= J[k] <= n. 
+Numerical zeros in (I, J, V) are retained as structural nonzeros; 
+to drop numerical zeros, use dropzeros!.
+"""
 sparsecsr(I,J,kwargs...) = SparseMatrixCSR(sparse(J,I,kwargs...))