restore abs for complex for symplicity

Author: ldeniau

src/madl_complex.mad

@@ -52,6 +52,7 @@ local is_complex = \a ->                         istype(complex, a)
 local is_scalar  = \a -> type(a) == 'number' or  istype(complex, a)
 
 -- generic functions
+M.abs   = \x -> _C.mad_cnum_abs_r   (x.re, x.im)
 M.ceil  = \x -> complex(ceil (x.re), ceil (x.im))
 M.floor = \x -> complex(floor(x.re), floor(x.im))
 M.frac  = \x -> complex(frac (x.re), frac (x.im))

src/madl_gtpsa.mad

@@ -1382,7 +1382,7 @@ MR.erfcx = \x -> exp(z^2)*erfc(z)
 
 -- ctpsa functions ------------------------------------------------------------o
 
-MC.abs = \ error("invalid operation 'abs' on complex GTPSA")
+MC.abs = \x,r -> MC.cabs(x, r)
 
 function MC.cabs (x, r)
   r = chksiz(r,x) or tpsa_alloc(x.d, x.mo)

src/madl_matrix.mad

@@ -1406,8 +1406,6 @@ MR.carg  = \ error("invalid argument #1 (cmatrix expected)")
 MR.rect  = \ error("invalid argument #1 (cmatrix expected)")
 MR.polar = \ error("invalid argument #1 (cmatrix expected)")
 
-MC.abs   = \ error("invalid argument #1 (matrix expected)")
-
 -- special folds --------------------------------------------------------------o
 
 local all = \p,r,x -> lbool(land(r, p(x)))