Group related classes

Flattens the header structure and group related classes together.

include/tc/group.hpp

@@ -0,0 +1,80 @@
+#pragma once
+
+#include <string>
+#include <sstream>
+
+#include <Eigen/Eigen>
+
+namespace {
+    template<class T>
+    std::string stringify(const T &vec) {
+        std::stringstream ss;
+        ss << "[" << vec << "]";
+        return ss.str();
+    }
+}
+
+namespace tc {
+    /// A Schlafli Matrix
+    template<unsigned int Rank>
+    class Group : public Eigen::Matrix<unsigned int, Rank, Rank> {
+    public:
+        using Base = Eigen::Matrix<unsigned int, Rank, Rank>;
+
+        std::string name;
+
+        using Base::Base;
+    };
+
+    template<unsigned int Rank>
+    using Symbol = Eigen::Vector<unsigned int, Rank>;
+
+    template<unsigned int Rank>
+    Group<Rank> schlafli(const Symbol<Rank - 1> &mults, const std::string &name) {
+        Group<Rank> res;
+        res.name = name;
+
+        res.fill(2);
+        res.topRightCorner(Rank - 1, Rank - 1).diagonal() << mults;
+        res.bottomLeftCorner(Rank - 1, Rank - 1).diagonal() << mults;
+
+        return res;
+    }
+
+    template<unsigned int Rank>
+    Group<Rank> schlafli(const Symbol<Rank - 1> &mults) {
+        return schlafli<Rank>(mults, stringify(mults));
+    }
+
+    template<unsigned int GR, unsigned int HR>
+    Group<GR + HR> product(const Group<GR> &g, const Group<HR> &h) {
+        Group<GR + HR> res;
+        res.name = g.name + "*" + h.name;
+
+        res.fill(2);
+
+        int off = 0;
+        res.block(off, off, GR, GR) << g.array() + off;
+        off += GR;
+
+        res.block(off, off, HR, HR) << h.array() + off;
+        off += HR;
+
+        return res;
+    }
+
+    template<unsigned int GR, unsigned int P>
+    Group<GR * P> power(const Group<GR> &g) {
+        Group<GR * P> res;
+        res.name = g.name + "^" + P;
+
+        res.fill(2);
+
+        for (int k = 0; k < P; ++k) {
+            int off = k * GR;
+            res.block(off, off, GR, GR) << g.array() + off;
+        }
+
+        return res;
+    }
+}