Thread Subject: changing a name of a variable form some stored string

 I have a problem in writing algorithm or getting the function to solve the problem like this:
a='y';
b=9;
 I want to change the name of the variable 'b' by 'y'.
please someone help me to solve this problem........

"rohit " <sci_vip@yahoo.co.in> wrote in message <h0eggt$6ff$1@fred.mathworks.com>...
> I have a problem in writing algorithm or getting the function to solve the problem like this:
> a='y';
> b=9;
> I want to change the name of the variable 'b' by 'y'.
> please someone help me to solve this problem........

I know the answer, but I won't tell you ...

First ask yourselve why you need to code it like you describe. A better, more versatile approach which is less prone to errors would be to use structs:

a = 'y'
b = 2
MyStruct.(a) = b

hth
Jos

"Jos " <#10584@fileexchange.com> wrote in message <h0eh3l$dvg$1@fred.mathworks.com>...
> "rohit " <sci_vip@yahoo.co.in> wrote in message <h0eggt$6ff$1@fred.mathworks.com>...
> > I have a problem in writing algorithm or getting the function to solve the problem like this:
> > a='y';
> > b=9;
> > I want to change the name of the variable 'b' by 'y'.
> > please someone help me to solve this problem........
>
> I know the answer, but I won't tell you ...
>
> First ask yourselve why you need to code it like you describe. A better, more versatile approach which is less prone to errors would be to use structs:
>
> a = 'y'
> b = 2
> MyStruct.(a) = b
>
> hth
> Jos

I would also like to know how to do this. I can successfully use the structure suggestion posted, but I would really like to have the data as a stand alone variable (easier to pass along and reference later in my gui's).

"Travis " <sinusoid2@hotmail.com> wrote in message <h3ba03$pse$1@fred.mathworks.com>...
> "Jos " <#10584@fileexchange.com> wrote in message <h0eh3l$dvg$1@fred.mathworks.com>...
> > "rohit " <sci_vip@yahoo.co.in> wrote in message <h0eggt$6ff$1@fred.mathworks.com>...
> > > I have a problem in writing algorithm or getting the function to solve the problem like this:
> > > a='y';
> > > b=9;
> > > I want to change the name of the variable 'b' by 'y'.
> > > please someone help me to solve this problem........
> >
> > I know the answer, but I won't tell you ...
> >
> > First ask yourselve why you need to code it like you describe. A better, more versatile approach which is less prone to errors would be to use structs:
> >
> > a = 'y'
> > b = 2
> > MyStruct.(a) = b
> >
> > hth
> > Jos
>
> I would also like to know how to do this. I can successfully use the structure suggestion posted, but I would really like to have the data as a stand alone variable (easier to pass along and reference later in my gui's).

% First method
eval([a '= b;']);

% Second method using WORKSPACE http://www.mathworks.com/matlabcentral/fileexchange/23078

ws = workspace; % FEX, called only once
a='y';
b=pi;
ws.(a)=b;
y

% Bruno

"Bruno Luong" <b.luong@fogale.findmycountry> wrote in message <h3bsrp$6vs$1@fred.mathworks.com>...
> "Travis " <sinusoid2@hotmail.com> wrote in message <h3ba03$pse$1@fred.mathworks.com>...
> > "Jos " <#10584@fileexchange.com> wrote in message <h0eh3l$dvg$1@fred.mathworks.com>...
> > > "rohit " <sci_vip@yahoo.co.in> wrote in message <h0eggt$6ff$1@fred.mathworks.com>...
> > > > I have a problem in writing algorithm or getting the function to solve the problem like this:
> > > > a='y';
> > > > b=9;
> > > > I want to change the name of the variable 'b' by 'y'.
> > > > please someone help me to solve this problem........
> > >
> > > I know the answer, but I won't tell you ...
> > >
> > > First ask yourselve why you need to code it like you describe. A better, more versatile approach which is less prone to errors would be to use structs:
> > >
> > > a = 'y'
> > > b = 2
> > > MyStruct.(a) = b
> > >
> > > hth
> > > Jos
> >
> > I would also like to know how to do this. I can successfully use the structure suggestion posted, but I would really like to have the data as a stand alone variable (easier to pass along and reference later in my gui's).
>
> % First method
> eval([a '= b;']);
>
> % Second method using WORKSPACE http://www.mathworks.com/matlabcentral/fileexchange/23078
>
> ws = workspace; % FEX, called only once
> a='y';
> b=pi;
> ws.(a)=b;
> y
>
> % Bruno

Thank you Bruno, as always you are a hige help. One more question. How would I go about making this new variable global within code? I am starting to think just attaching it to a pre-existing struct, which is global, might be easier and cleaner.

"Bruno Luong" <b.luong@fogale.findmycountry> wrote in message <h3bsrp$6vs$1@fred.mathworks.com>...
> "Travis " <sinusoid2@hotmail.com> wrote in message <h3ba03$pse$1@fred.mathworks.com>...
> > "Jos " <#10584@fileexchange.com> wrote in message <h0eh3l$dvg$1@fred.mathworks.com>...
> > > "rohit " <sci_vip@yahoo.co.in> wrote in message <h0eggt$6ff$1@fred.mathworks.com>...
> > > > I have a problem in writing algorithm or getting the function to solve the problem like this:
> > > > a='y';
> > > > b=9;
> > > > I want to change the name of the variable 'b' by 'y'.
> > > > please someone help me to solve this problem........
> > >
> > > I know the answer, but I won't tell you ...
> > >
> > > First ask yourselve why you need to code it like you describe. A better, more versatile approach which is less prone to errors would be to use structs:
> > >
> > > a = 'y'
> > > b = 2
> > > MyStruct.(a) = b
> > >
> > > hth
> > > Jos
> >
> > I would also like to know how to do this. I can successfully use the structure suggestion posted, but I would really like to have the data as a stand alone variable (easier to pass along and reference later in my gui's).
>
> % First method
> eval([a '= b;']);
>
> % Second method using WORKSPACE http://www.mathworks.com/matlabcentral/fileexchange/23078
>
> ws = workspace; % FEX, called only once
> a='y';
> b=pi;
> ws.(a)=b;
> y
>
> % Bruno

Thank you Bruno, as always you are a hige help. One more question. How would I go about making this new variable global within code? I am starting to think just attaching it to a pre-existing struct, which is global, might be easier and cleaner.

"Travis " <sinusoid2@hotmail.com> wrote in message <h3c10v$snf$1@fred.mathworks.com>...

>
> Thank you Bruno, as always you are a hige help. One more question. How would I go about making this new variable global within code? I am starting to think just attaching it to a pre-existing struct, which is global, might be easier and cleaner.

You can still use EVAL with GLOBAL. But EVAL alone is EVIL enough. If you put EVAL together GLOBAL, that would be EVIL power two or a true global evil. LOL. Yes put it in struct is better.

Bruno

"Bruno Luong" <b.luong@fogale.findmycountry> wrote in message <h3c32h$d19$1@fred.mathworks.com>...
> "Travis " <sinusoid2@hotmail.com> wrote in message <h3c10v$snf$1@fred.mathworks.com>...
>
> >
> > Thank you Bruno, as always you are a hige help. One more question. How would I go about making this new variable global within code? I am starting to think just attaching it to a pre-existing struct, which is global, might be easier and cleaner.
>
> You can still use EVAL with GLOBAL. But EVAL alone is EVIL enough. If you put EVAL together GLOBAL, that would be EVIL power two or a true global evil. LOL. Yes put it in struct is better.
>
> Bruno

haha, thanks Bruno, I will stick with the structures.

"Travis " <sinusoid2@hotmail.com> wrote in message
news:h3ba03$pse$1@fred.mathworks.com...
> "Jos " <#10584@fileexchange.com> wrote in message
> <h0eh3l$dvg$1@fred.mathworks.com>...
>> "rohit " <sci_vip@yahoo.co.in> wrote in message
>> <h0eggt$6ff$1@fred.mathworks.com>...
>> > I have a problem in writing algorithm or getting the function to solve
>> > the problem like this:
>> > a='y';
>> > b=9;
>> > I want to change the name of the variable 'b' by 'y'.
>> > please someone help me to solve this problem........
>>
>> I know the answer, but I won't tell you ...
>>
>> First ask yourselve why you need to code it like you describe. A better,
>> more versatile approach which is less prone to errors would be to use
>> structs:
>>
>> a = 'y'
>> b = 2
>> MyStruct.(a) = b
>>
>> hth
>> Jos
>
> I would also like to know how to do this. I can successfully use the
> structure suggestion posted, but I would really like to have the data as a
> stand alone variable (easier to pass along and reference later in my
> gui's).

I strongly encourage you NOT to create variables like this at runtime. Read
Q4.6 in the FAQ:

http://matlabwiki.mathworks.com/MATLAB_FAQ

--
Steve Lord
slord@mathworks.com

"Steven Lord" <slord@mathworks.com> wrote in message <h3dvuf$eiu$1@fred.mathworks.com>...
>
> "Travis " <sinusoid2@hotmail.com> wrote in message
> news:h3ba03$pse$1@fred.mathworks.com...
> > "Jos " <#10584@fileexchange.com> wrote in message
> > <h0eh3l$dvg$1@fred.mathworks.com>...
> >> "rohit " <sci_vip@yahoo.co.in> wrote in message
> >> <h0eggt$6ff$1@fred.mathworks.com>...
> >> > I have a problem in writing algorithm or getting the function to solve
> >> > the problem like this:
> >> > a='y';
> >> > b=9;
> >> > I want to change the name of the variable 'b' by 'y'.
> >> > please someone help me to solve this problem........
> >>
> >> I know the answer, but I won't tell you ...
> >>
> >> First ask yourselve why you need to code it like you describe. A better,
> >> more versatile approach which is less prone to errors would be to use
> >> structs:
> >>
> >> a = 'y'
> >> b = 2
> >> MyStruct.(a) = b
> >>
> >> hth
> >> Jos
> >
> > I would also like to know how to do this. I can successfully use the
> > structure suggestion posted, but I would really like to have the data as a
> > stand alone variable (easier to pass along and reference later in my
> > gui's).
>
> I strongly encourage you NOT to create variables like this at runtime. Read
> Q4.6 in the FAQ:
>
> http://matlabwiki.mathworks.com/MATLAB_FAQ
>
> --
> Steve Lord
> slord@mathworks.com
>

I found that using the preexisting structure works quite well, I had in my mind that a stand alone variable would be better, but it looks like passing it along will create numerous other issues and complications that the structure will not.