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From: Brendan on 23 Feb 2010 16:56
Hello,

In my code I have a cell array EofGgivenXjU which is a set of vectors. For example, EofGgivenXjU{1} is a 1x m vector, EofGgivenXjU{2} is a 1xn vector, etc. What I would like to do is update a specific position of that vector. For example, lets say that EofGgivenXjU{1}=[0,0,0,0], I would like to then make it =[0,1,0,0].

I have included what I am doing now, which includes two different ways I have come up with two different ways to do what I have proposed, but I'm wondering if there is a more efficient way. Specifically, numDisc(jj) is the length of the vector of EofGgivenXjU{jj}, and D(ii,jj) is a matrix which indicates which element I want to increment.

for ii=1:numIter
newTermU=3*ii;
for jj=1:numVars
blah=zeros(1,numDisc(jj));
blah(D(ii,jj))=blah(D(ii,jj))+newTermU;
EofGgivenXjU{jj}=EofGgivenXjU{jj}+blah;

blah2=EofGgivenXjL{jj};
blah2(D(ii,jj))=blah2(D(ii,jj))+newTermL;
EofGgivenXjL{jj}=blah2;
end
end

Thank you for your help
From: Wayne King on 23 Feb 2010 17:40
"Brendan " <btracey(a)stanford.edu> wrote in message <hm1iu6$i0k$1(a)fred.mathworks.com>...
> Hello,
>
> In my code I have a cell array EofGgivenXjU which is a set of vectors. For example, EofGgivenXjU{1} is a 1x m vector, EofGgivenXjU{2} is a 1xn vector, etc. What I would like to do is update a specific position of that vector. For example, lets say that EofGgivenXjU{1}=[0,0,0,0], I would like to then make it =[0,1,0,0].
>
> I have included what I am doing now, which includes two different ways I have come up with two different ways to do what I have proposed, but I'm wondering if there is a more efficient way. Specifically, numDisc(jj) is the length of the vector of EofGgivenXjU{jj}, and D(ii,jj) is a matrix which indicates which element I want to increment.
>
> for ii=1:numIter
> newTermU=3*ii;
> for jj=1:numVars
> blah=zeros(1,numDisc(jj));
> blah(D(ii,jj))=blah(D(ii,jj))+newTermU;
> EofGgivenXjU{jj}=EofGgivenXjU{jj}+blah;
>
> blah2=EofGgivenXjL{jj};
> blah2(D(ii,jj))=blah2(D(ii,jj))+newTermL;
> EofGgivenXjL{jj}=blah2;
> end
> end
>
> Thank you for your help

Hi Brendan,

> What I would like to do is update a specific position of that vector. For example, lets >say that EofGgivenXjU{1}=[0,0,0,0], I would like to then make it =[0,1,0,0].
You can directly address a particular element of a cell array like this

NewCell = cell(2,3); NewCell{1}=zeros(1,3);
NewCell{1}(2)=1;
% NewCell{1} is now 0 1 0
NewCell{1}

For a matrix, use the regular matrix indexing to address elements:

NewCell{2}=zeros(2,2);
NewCell{2}(1,2)=1; NewCell{2}

Hope that helps,
Wayne
From: Brendan on 23 Feb 2010 19:50
"Wayne King" <wmkingty(a)gmail.com> wrote in message <hm1lgp$3qs$1(a)fred.mathworks.com>...
> "Brendan " <btracey(a)stanford.edu> wrote in message <hm1iu6$i0k$1(a)fred.mathworks.com>...
> > Hello,
> >
> > In my code I have a cell array EofGgivenXjU which is a set of vectors. For example, EofGgivenXjU{1} is a 1x m vector, EofGgivenXjU{2} is a 1xn vector, etc. What I would like to do is update a specific position of that vector. For example, lets say that EofGgivenXjU{1}=[0,0,0,0], I would like to then make it =[0,1,0,0].
> >
> > I have included what I am doing now, which includes two different ways I have come up with two different ways to do what I have proposed, but I'm wondering if there is a more efficient way. Specifically, numDisc(jj) is the length of the vector of EofGgivenXjU{jj}, and D(ii,jj) is a matrix which indicates which element I want to increment.
> >
> > for ii=1:numIter
> > newTermU=3*ii;
> > for jj=1:numVars
> > blah=zeros(1,numDisc(jj));
> > blah(D(ii,jj))=blah(D(ii,jj))+newTermU;
> > EofGgivenXjU{jj}=EofGgivenXjU{jj}+blah;
> >
> > blah2=EofGgivenXjL{jj};
> > blah2(D(ii,jj))=blah2(D(ii,jj))+newTermL;
> > EofGgivenXjL{jj}=blah2;
> > end
> > end
> >
> > Thank you for your help
>
> Hi Brendan,
>
> > What I would like to do is update a specific position of that vector. For example, lets >say that EofGgivenXjU{1}=[0,0,0,0], I would like to then make it =[0,1,0,0].
> You can directly address a particular element of a cell array like this
>
> NewCell = cell(2,3); NewCell{1}=zeros(1,3);
> NewCell{1}(2)=1;
> % NewCell{1} is now 0 1 0
> NewCell{1}
>
> For a matrix, use the regular matrix indexing to address elements:
>
> NewCell{2}=zeros(2,2);
> NewCell{2}(1,2)=1; NewCell{2}
>
> Hope that helps,
> Wayne


It does, thank you very much. If you don't mind a followup:

Given the way my code is actually structured, I'm pretty sure I can't vectorize the outer loop, but is there a way to vectorize the inner loop, i.e. replace the for jj=1:numVars loop with some sort of colon structure?

for ii=1:numIter
newTermU=3*ii;
for jj=1:numVars
EofGgivenXjU{jj}(D(ii,jj))=EofGgivenXjU{jj}(D(ii,jj))+newTermU;
end
end
From: Nathan on 23 Feb 2010 19:57
On Feb 23, 4:50 pm, "Brendan " <btra...(a)stanford.edu> wrote:
> "Wayne King" <wmkin...(a)gmail.com> wrote in message <hm1lgp$3q...(a)fred.mathworks.com>...
> > "Brendan " <btra...(a)stanford.edu> wrote in message <hm1iu6$i0...(a)fred.mathworks.com>...
> > > Hello,
>
> > > In my code I have a cell array EofGgivenXjU which is a set of vectors.. For example, EofGgivenXjU{1} is a 1x m vector, EofGgivenXjU{2} is a 1xn vector, etc.  What I would like to do is update a specific position of that vector. For example, lets say that EofGgivenXjU{1}=[0,0,0,0], I would like to then make it =[0,1,0,0].
>
> > > I have included what I am doing now, which includes two different ways I have come up with two different ways to do what I have proposed, but I'm wondering if there is a more efficient way. Specifically, numDisc(jj) is the length of the vector of EofGgivenXjU{jj}, and D(ii,jj) is a matrix which indicates which element I want to increment.
>
> > > for ii=1:numIter
> > >     newTermU=3*ii;
> > >     for jj=1:numVars
> > >         blah=zeros(1,numDisc(jj));
> > >         blah(D(ii,jj))=blah(D(ii,jj))+newTermU;
> > >         EofGgivenXjU{jj}=EofGgivenXjU{jj}+blah;
>
> > >         blah2=EofGgivenXjL{jj};
> > >         blah2(D(ii,jj))=blah2(D(ii,jj))+newTermL;
> > >         EofGgivenXjL{jj}=blah2;
> > >     end
> > > end
>
> > > Thank you for your help
>
> > Hi Brendan,
>
> > > What I would like to do is update a specific position of that vector. For example, lets >say that EofGgivenXjU{1}=[0,0,0,0], I would like to then make it =[0,1,0,0].
> > You can directly address a particular element of a cell array like this
>
> > NewCell = cell(2,3); NewCell{1}=zeros(1,3);
> > NewCell{1}(2)=1;
> > % NewCell{1} is now 0 1 0
> > NewCell{1}
>
> > For a matrix, use the regular matrix indexing to address elements:
>
> > NewCell{2}=zeros(2,2);
> > NewCell{2}(1,2)=1; NewCell{2}
>
> > Hope that helps,
> > Wayne
>
> It does, thank you very much. If you don't mind a followup:
>
> Given the way my code is actually structured, I'm pretty sure I can't vectorize the outer loop, but is there a way to vectorize the inner loop, i.e. replace the for jj=1:numVars loop with some sort of colon structure?
>
> for ii=1:numIter
>     newTermU=3*ii;
>     for jj=1:numVars
>         EofGgivenXjU{jj}(D(ii,jj))=EofGgivenXjU{jj}(D(ii,jj))+newTermU;
>     end
> end

Have you tried something like this:

for ii=1:numIter
newTermU=3*ii;
jj=1:numVars; %jj is a vector to index the next line
EofGgivenXjU{jj}(D(ii,jj))=EofGgivenXjU{jj}(D(ii,jj))+newTermU;
end

-Nathan
From: Brendan on 23 Feb 2010 20:12
Nathan <ngreco32(a)gmail.com> wrote in message <55880c2a-0994-40af-b08a-f7f7b7834e9e(a)k36g2000prb.googlegroups.com>...

> > Given the way my code is actually structured, I'm pretty sure I can't vectorize the outer loop, but is there a way to vectorize the inner loop, i.e. replace the for jj=1:numVars loop with some sort of colon structure?
> >
> > for ii=1:numIter
> >     newTermU=3*ii;
> >     for jj=1:numVars
> >         EofGgivenXjU{jj}(D(ii,jj))=EofGgivenXjU{jj}(D(ii,jj))+newTermU;
> >     end
> > end
>
> Have you tried something like this:
>
> for ii=1:numIter
> newTermU=3*ii;
> jj=1:numVars; %jj is a vector to index the next line
> EofGgivenXjU{jj}(D(ii,jj))=EofGgivenXjU{jj}(D(ii,jj))+newTermU;
> end
>
> -Nathan

I hadn't tried that, it's a nice thought, but it gives me a "Bad cell reference operation" error
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