Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: matlab version and "for" loops
Replies: 15   Last Post: Feb 13, 2013 4:53 PM

 Messages: [ Previous | Next ]
 Candace Posts: 41 Registered: 10/20/12
Re: matlab version and "for" loops
Posted: Feb 13, 2013 4:53 PM

dpb <none@non.net> wrote in message <kfdui8\$66t\$1@speranza.aioe.org>...
> On 2/12/2013 10:07 AM, Jessica wrote:
> > "Jessica " <jly5@duke.edu> wrote in message
> > <ke3bjs\$b6t\$1@newscl01ah.mathworks.com>...

> >> dpb <none@non.net> wrote in message <ke2bbi\$98i\$1@speranza.aioe.org>...
> >> > On 1/26/2013 4:50 PM, Jessica wrote:
> >> > > "Jessica " <jly5@duke.edu> wrote in message
> >> > > <kdmql8\$n4i\$1@newscl01ah.mathworks.com>...

> >> > >> "Bruno Luong" <b.luong@fogale.findmycountry> wrote in message
> >> > >> <kdlt80\$st0\$1@newscl01ah.mathworks.com>...

> >> > ...
> >> > > >> > Data(delete) = []
> >> > ...
> >> > > > And, one other question. If I want to do the same as above
> >> except delete
> >> > > based on numbers, how would I do that? If I do:
> >> > >
> >> > > delete_b = GazeType(GazeType>10)
> >> > >
> >> > > it only lists the numbers that are greater than 10 and I therefore
> >> > > cannot delete those rows.
> >> > > Generalize the rule Bruno illustrated--
> >> > > GazeType(GazeType>10)=[];
> >> > > --

> >> >
> >> Unfortunately, this won't quite work because I am trying to delete
> >> rows within larger data sets:
> >>
> >>
> >> First, I isolate the column I am interested in:
> >>
> >> RemoveColumn3=Total4(:, 11);
> >>
> >> Then I wanted to generate a variable (just like I did above when the
> >> value was a string), that indicates the rows to be deleted (which are
> >> greater than 10).
> >>
> >> And then, delete those specific rows within 2 datasets:
> >> Total4(delete) = []
> >> Target4(delete) = []

> >
> >
> > I am having some trouble generalizing this logical method. Specifically,
> > I am reading in a .csv file and trying to delete "Rows" that have even
> > numbers:
> >
> > FinalDataSet=Dataset.data;
> > FinalDataSet2=Dataset.data;
> > Row=Dataset.data(:,5);
> > tf=bitget(abs(Row),1)~=0;
> > FinalDataSet2(tf)=[];
> >
> > However, "FinalDataSet2" is originally sized as 81539x6. When I delete
> > the "tf" values, it turns into a variable that is sized as 1x448465.
> >
> > Can anyone suggest what I am doing incorrectly here?

>
> Well, when you don't remove elements such that those being removed are
> specified as either complete rows or columns the result can't be a
> regularly spaced array and so ML returns a vector.
>
> Given a (short) example dataset that illustrates the input and desired
> results.
>
> Reading the first part literally, to eliminate rows w/ even indices simply
>
> x(2:2:end,:)=[];
>
> does that job.
>
> --

That was a big help-- thanks for the tip!

Date Subject Author
1/21/13 Jan Simon
1/21/13 Jessica
1/21/13 Bruno Luong
1/22/13 Jessica
1/21/13 Bruno Luong
1/22/13 Bruno Luong
1/22/13 Candace
1/26/13 Candace
1/26/13 gautamsethi@gmail.com
1/26/13 gautamsethi@gmail.com
1/26/13 dpb
1/27/13 Candace
2/12/13 Candace
2/12/13 dpb
2/13/13 Candace