add fillVandermonde (#218)

* add fillVandermonde

* fixup

Author: 9il

doc/Makefile

@@ -48,6 +48,7 @@ PACKAGE_mir_ndslice = \
 	concatenation\
 	dynamic\
 	field\
+	filling\
 	fuse\
 	iterator\
 	mutation\

meson.build

@@ -40,6 +40,7 @@ mir_algorithm_src = [
     'source/mir/ndslice/connect/cpython.d',
     'source/mir/ndslice/dynamic.d',
     'source/mir/ndslice/field.d',
+    'source/mir/ndslice/filling.d',
     'source/mir/ndslice/fuse.d',
     'source/mir/ndslice/internal.d',
     'source/mir/ndslice/iterator.d',

source/mir/ndslice/filling.d

@@ -0,0 +1,42 @@
+/++
+This is a submodule of $(MREF mir,ndslice).
+
+Initialisation routines.
+
+License:   $(HTTP boost.org/LICENSE_1_0.txt, Boost License 1.0).
+Copyright: 2019 Symmetry Investments Group and Kaleidic Associates Advisory Limited.
+Authors:   Ilya Yaroshenko
+
+Macros:
+SUBREF = $(REF_ALTTEXT $(TT $2), $2, mir, ndslice, $1)$(NBSP)
+T2=$(TR $(TDNW $(LREF $1)) $(TD $+))
++/
+module mir.ndslice.filling;
+
+import mir.ndslice.slice: Slice, SliceKind;
+
+/++
+Fills a matrix with the terms of a geometric progression in each row.
+Params:
+    matrix = `m × n` matrix to fill
+    vec = vector of progression coefficients length of `m`
++/
+void fillVandermonde(F, SliceKind matrixKind, SliceKind kind)(Slice!(F*, 2, matrixKind) matrix, Slice!(const(F)*, 1, kind) vec)
+in {
+    assert(matrix.length == vec.length);
+}
+body {
+    import mir.conv: to;
+
+    foreach (v; matrix)
+    {
+        F a = vec.front;
+        vec.popFront;
+        F x = to!F(1);
+        foreach (ref e; v)
+        {
+            e = x;
+            x *= a;
+        }
+    }
+}

source/mir/ndslice/package.d

@@ -172,6 +172,13 @@ $(TR $(TDNW $(SUBMODULE topology) $(BR)
     )
 )
 
+$(TR $(TDNW $(SUBMODULE filling) $(BR)
+    $(SMALL Specialized initialisation routines))
+     $(TD
+        $(SUBREF filling, fillVandermonde)
+    )
+)
+
 $(TR $(TDNW $(SUBMODULE fuse) $(BR)
     $(SMALL Data fusing (stacking)
         $(BR) See also $(SUBMODULE concatenation) submodule.
@@ -474,6 +481,7 @@ public import mir.ndslice.concatenation;
 public import mir.ndslice.chunks;
 public import mir.ndslice.dynamic;
 public import mir.ndslice.field;
+public import mir.ndslice.filling;
 public import mir.ndslice.fuse;
 public import mir.ndslice.iterator;
 public import mir.ndslice.ndfield;

source/mir/ndslice/slice.d

@@ -271,9 +271,11 @@ auto sliced(size_t N, Iterator)(Iterator iterator, size_t[N] lengths...)
         return ret;
     }
 
-    import mir.ndslice.topology: universal;
+    import mir.ndslice.filling: fillVandermonde;
+    import mir.ndslice.allocation: uninitSlice;
     auto x = [1.0, 2, 3, 4, 5].sliced;
-    auto v = vandermondeMatrix(x);
+    auto v = uninitSlice!double(x.length, x.length);
+    v.fillVandermonde(x);
     assert(v ==
         [[  1.0,   1,   1,   1,   1],
          [  1.0,   2,   4,   8,  16],