Bootci usage: passing vectors into function

Hi,

I am trying to use bootci to generate confidence intervals on a fit to data. My code is:

[ci,bootstat] = bootci(100,{fitData,data,v1,v2,scalar},'alpha',.1)

where fitData is a function that returns a scalar from the fit to data (data is the set to be sampled with replacement). The variables v1 and v2 (two vectors) and one scalar are needed by the function.

As I understand it, the problem is that the function, fitData, also needs those two vectors v1 and v2. However, I do not wish to sample from. My understanding from the documentation is bootstrp and bootci automatically samples from all vectors passed to the function. Is this correct? If it is, is there a way to change that?

Thanks, Gabriela

Answer 1

[Oleg Komarov]

% Inputs
y  = randn(100,1);                 
v1 = 1:10;
v2 = 10:-1:1;

% Only 'x' is the input since we fix v1 and v2 (same name as vars)
f  = @(x) foo(v1,v2,x);

% Bootstrap f by sampling from y (the only input x)
ci = bootci(2000,{f,y},'alpha',.1);

Where foo is

function out = foo(in1,in2,data)
   out = sum(in1*in2.' + data);
end