Re: String Index

[Thomas D. Dean]

On 06/26/2016 09:56 PM, PhilipNienhuis wrote:
> Thomas D. Dean-2 wrote
> > I have a string, 87 characters. containing pairs of parens enclosing
> > characters.  The number of chars enclosed is not constant.  There are 2
> > to 5 pairs of parens.  How do I construct the index to vectorize this?
> >
> >   > n=numel(str)
> > n =  87
> >   > lp = [1:n](str == "(");
> >   > rp = [1:n](str == ")");
> >   > ## check to see if parens paired and lp < rp
> >   > [lp', rp']
> > ans =
> >      38   47
> >      54   57
> >      66   73
> >      85   87
> >
> > I want to extract values from str using lp and rp
> >
> >   > [ str(lp(1):rp(1));
> >   >   str(lp(2):rp(2));
> >   >   str(lp(3):rp(3));
> >   >   str(lp(4):rp(4)) ]
> > ans =
> > (10^20 kg)
> > (km)
> > (kg/m^3)
> > (1)
>
> Read up on regexp()

I played with regexp() some, but, could not find a pattern that matched 
just the characters within the parens.

> str

> str = "_units_           (10^15 kg)         (km)          (kg/m^3)   "
> [s, e, te, m, t, nm, sp] = regexp(str,"\(...\){3,5}");m
> m
m =
{
  [1,1] = _units_
  [1,2] =    (10^15 kg)
  [1,3] =        (km)
  [1,4] =       (kg/m^3)

}

is close, but, still needs some parsing.  Most likely not better than 
using strtok.

Tom Dean