🚀 go-pugleaf

In article <1993Jan18.155531.4025@tdb.uu.se> Peter Haegglund,
peterh@tdb.uu.se writes:
>: Hi,
>: 	Just curious whether a couple of parser bugs/quirks have been fixed
>: in version 4.0.  Two such quirks that come to mind are:
>: 
>: 1)
>: >> 4 * -1	% this will result in an error
>: >> 4 * (-1)	% this will work
>: 
>: 2)
>: >> [1 + 2 * 3, 4]	% how many elements in this matrix?
>: 
>: This handling of unary operators is just a little unintuitive --
usually
>: mere nuisance value.

The first of these "quirks" is a reasonable suggestion and I'll see that
it is added to our "wish list" for possible inclusion into a future
version of MATLAB.

The second of these two "quirks" has been "improved". As several other
people point out, spaces are significant inside brackets.  This is
a "nice" feature in that it allows statements like

   a = [a b; c d]
   a = [1 2 3 4 5 6]

rather than requiring commas between matrix elements. However using 
MATLAB 3.5 the statement

   a = [1 + 2 * 3, 4]
   
gives you

   a = 1  6  4

because the "+" is treated as the sign on the 2. Using MATLAB 4.0 this 
now returns an answer that is more likely to be what you intended:
   

   a  =  7   4
   
We noticed too that if there are spaces around the operator then it
is unambiguous what you want.


John Little
little@mathworks.com