Re: Error message: subscript indices must be either positive integers or logicals

[Juan Pablo Carbajal]

On Sun, Oct 9, 2011 at 5:33 PM, preeti gaikwad <address@hidden> wrote:
> li is absorption length and lt is scattering mean free path......so I have
> to find these variables via leasqr......even I know the guess value for the
> same that I am taking li=2mm and lt is 0.5 mm.....thanks for the help
>
>
>
>
> On 9 October 2011 17:31, Juan Pablo Carbajal <address@hidden> wrote:
>>
>> On Sun, Oct 9, 2011 at 4:52 PM, preeti gaikwad <address@hidden>
>> wrote:
>> >
>> > Hello all, I am the new user or octave and would like to get help on
>> > this
>> > error message "subscript indices must be either positive integers or
>> > logicals"
>> > I am using the function
>> >
>> > .....................................................................
>> >
>> > for i=-10:1:10
>> >
>> > z0 = (2/3)*lt*(1+R)/(1-R);
>> >
>> > ze = (li/2)*log((1+(1/li)*z0)/(1-(1/li)*z0));
>> >
>> > zp = ze;
>> >
>> > A=(1-2*i)(L+2*ze)-2*(zp+lt);
>> >
>> > B=(2*i+1)(L+2*ze);
>> >
>> > Taui=li^2/D;
>> >
>> > T=exp(-(x./Taui)).*(A.*exp([(-(A^2))/4*D.*x])-B*exp([(-B^2)/4*D.*x]));
>> >
>> >
>> >
>> > end
>> >
>> > F=T(1:nr);
>> >
>> >
>> > .......................................................................where
>> > nr is the value of x
>> > and the value of D, li, lt are unknown and L and R is defined. I am
>> > using
>> > leasqr to call this function and fitted this function in my experimental
>> > results......All the time it is saying that A is not define and
>> > "subscript
>> > indices must be either positive integers or logicals"
>> > the value of A has some problem I think but I am not getting
>> > what.....please
>> > help me for the same
>> >
>> > _______________________________________________
>> > Help-octave mailing list
>> > address@hidden
>> > https://mailman.cae.wisc.edu/listinfo/help-octave
>> >
>> >
>>
>> Welcome to Octave!
>>
>> Can you tell what are lt and li?
>>
>> --
>> M. Sc. Juan Pablo Carbajal
>> -----
>> PhD Student
>> University of Zürich
>> http://ailab.ifi.uzh.ch/carbajal/
>
>
>
> --
> preeti gaikwad
>

Ok, li and lt are scalars. I assume R,L, D are also scalars. In that
case everything looks ok, except for T. If you want T to be a function
you have to do it this way

T =@(x) <your formula>

You could also define a function file.

Does this help?




-- 
M. Sc. Juan Pablo Carbajal
-----
PhD Student
University of Zürich
http://ailab.ifi.uzh.ch/carbajal/