Optimize block map construction and multiplication (#52)

Author: dkarrasch

.travis.yml

@@ -7,6 +7,7 @@ julia:
   - 1.0
   - 1.1
   - 1.2
+  - 1.3
   - nightly
 
 matrix:

Project.toml

@@ -1,6 +1,6 @@
 name = "LinearMaps"
 uuid = "7a12625a-238d-50fd-b39a-03d52299707e"
-version = "2.4.0"
+version = "2.5.0"
 
 [deps]
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"

README.md

@@ -7,6 +7,15 @@
 
 A Julia package for defining and working with linear maps, also known as linear transformations or linear operators acting on vectors. The only requirement for a LinearMap is that it can act on a vector (by multiplication) efficiently.
 
+## What's new in v2.5.0
+*   New feature: concatenation of `LinearMap`s objects with `UniformScaling`s,
+    consistent with (h-, v-, and hc-)concatenation of matrices. Note, matrices
+    `A` must be wrapped as `LinearMap(A)`, `UniformScaling`s are promoted to
+    `LinearMap`s automatically.
+
+## What's new in v2.4.0
+*   Support restricted to Julia v1.0+.
+
 ## What's new in v2.3.0
 *   Fully Julia v0.7/v1.0/v1.1 compatible.
 *   Full support of noncommutative number types such as quaternions.
@@ -89,6 +98,10 @@ The LinearMaps package provides the following functionality:
 
     Applying the adjoint or transpose of `A` (if defined) to `x` works exactly as in the usual matrix case: `transpose(A) * x` and `mul!(y, A', x)`, for instance.
 
+*   Horizontal, vertical, and hv-concatenation as known for regular matrices,
+    where `UniformScaling`s are automatically promoted to `LinearMap`s and their
+    sizes are inferred, if possible.
+
 ## Types
 
 None of the types below need to be constructed directly; they arise from performing