1 files changed, 50 insertions, 0 deletions
diff --git a/src/libnr/nr-matrix-fns.h b/src/libnr/nr-matrix-fns.h
new file mode 100644
index 000000000..208366746
--- /dev/null
+++ b/src/libnr/nr-matrix-fns.h
@@ -0,0 +1,50 @@
+#ifndef SEEN_NR_MATRIX_FNS_H
+#define SEEN_NR_MATRIX_FNS_H
+
+#include "nr-matrix.h"
+
+namespace NR {
+
+/** Given a matrix m such that unit_circle = m*x, this returns the
+ * quadratic form x*A*x = 1. */
+Matrix elliptic_quadratic_form(Matrix const &m);
+
+/** Given a matrix (ignoring the translation) this returns the eigen
+ * values and vectors. */
+class Eigen{
+public:
+    Point vectors[2];
+    Point values;
+    Eigen(Matrix const &m);
+};
+
+// Matrix factories
+Matrix from_basis(const Point x_basis, const Point y_basis, const Point offset=Point(0,0));
+
+Matrix identity();
+
+double expansion(Matrix const &m);
+
+bool transform_equalp(Matrix const &m0, Matrix const &m1, NR::Coord const epsilon);
+bool translate_equalp(Matrix const &m0, Matrix const &m1, NR::Coord const epsilon);
+bool matrix_equalp(Matrix const &m0, Matrix const &m1, NR::Coord const epsilon);
+
+Matrix transform(Matrix const &m);
+translate get_translation(Matrix const &m);
+
+void matrix_print(const gchar *say, Matrix const &m);
+
+}  // namespace NR
+
+#endif /* !SEEN_NR_MATRIX_FNS_H */
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :