updated readme, added license

Author: j-fu

LICENSE

@@ -0,0 +1,34 @@
+LICENSE
+
+ExtendableSparse.jl is open-source code licensed under the BSD license.
+
+Copyright (c) 2018 Jürgen Fuhrmann <juergen.fuhrmann@wias-berlin.de>
+
+All rights reserved.
+
+Redistribution and  use in  source and binary  forms, with  or without
+modification, are permitted provided that the following conditions are
+met:
+
+1.  Redistributions of  source code  must retain  the above  copyright
+notice, this list of conditions and the following disclaimer.
+
+2. Redistributions in  binary form must reproduce  the above copyright
+notice, this  list of conditions  and the following disclaimer  in the
+documentation and/or other materials provided with the distribution.
+
+3. Neither name  of Jürgen Fuhrmann nor the names  of any contributors
+may be used to endorse or  promote products derived from this software
+without specific prior written permission.
+
+THIS SOFTWARE  IS PROVIDED BY  THE COPYRIGHT HOLDERS  AND CONTRIBUTORS
+AS  IS” AND  ANY EXPRESS  OR IMPLIED  WARRANTIES, INCLUDING,  BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES  OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN  NO EVENT SHALL THE AUTHORS OR
+CONTRIBUTORS BE LIABLE FOR  ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+EXEMPLARY, OR  CONSEQUENTIAL DAMAGES  (INCLUDING, BUT NOT  LIMITED TO,
+PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS  OF USE,  DATA, OR
+PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER  IN CONTRACT, STRICT LIABILITY,  OR TORT (INCLUDING
+NEGLIGENCE OR  OTHERWISE) ARISING IN  ANY WAY OUT  OF THE USE  OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

README.md

@@ -1,9 +1,10 @@
 # ExtendableSparse
 
-Sparse matrix class with efficient assembly.
+Sparse matrix class with efficient successive insertion of entries.
 
-While SparseMatrixCSC is extendable as well, extending it is expensive for larger problems,
-due to the implementation of extension without an intermediate data structure.
+Without an intermediate data structure, efficient successive insertion/update of entries in random order into a standard compressed colume storage structure appears to be not possible. The package introduces ``ExtendableSparseMatrix``, a delegating wrapper around the Julia standard ``SparseMatrixCSC`` struct which contains an additional linked list based (but realised in vectors) temporary extension structure.
 
+``ExtendableSparseMatrix`` is aimed to work as a drop-in replacement to ``SparseMatrixCSC`` in finite element and finite volume codes.
 
+Currently it has the methods required for ``AbstractSparseMatrix`` (``getindex``, ``setindex!``,``size``,``nnz``), as well as ``lufact`` and ``mul!``, which is already sufficient for a number of interesting applications.