(def m (fm/seq->double-double-array [[1 2 3][4 5 6][7 8 9]]))
(def I (fmat/eye 3))
(fmat/mulm I m)
; eval (effective-root-form): (fmat/mulm I m)
; (err) Execution error (ClassCastException) at fastmath.matrix.Mat3x3/mulm (matrix.clj:313).
; (err) class [[D cannot be cast to class fastmath.matrix.Mat3x3 ([[D is in module java.base of loader 'bootstrap'; fastmath.matrix.Mat3x3 is in unnamed module of loader clojure.lang.DynamicClassLoader @c1e1f4c)
(def Ireal (fmat/eye 3 true))
(fmat/mulm Ireal m)
; eval (effective-root-form): (fmat/mulm Ireal m)
; (err) Execution error (ClassCastException) at fastmath.matrix/eval41805$fn (matrix.clj:686).
; (err) class [[D cannot be cast to class org.apache.commons.math3.linear.RealMatrix ([[D is in module java.base of loader 'bootstrap'; org.apache.commons.math3.linear.RealMatrix is in unnamed module of loader 'app')
;; this works:
(def Idouble (fm/seq->double-double-array [[1 0 0][0 1 0][0 0 1]]))
(fmat/mulm Idouble m)
