Problem using nlinfit function
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Hi everyone,
I am having trouble using nlinfit for making a regression with an own function.
I have the following script:
xdata = 1:150;
xdata = xdata';
ydata = beta;
beta0 = [0 -1 20];
n = 1:150;
y = nlinfit(xdata,ydata,fun,beta0);.
and the function fun.m is this:
function y = fun(beta0,n);
y = beta0(1)+ beta(2).*exp(-n/beta(3));
The basic original function that I want to use is a +be^(t/tau) to fit a set of data points:
I have tried a lot, but I get different errors, variables not defined, input must be 4 variables etc. Please help me out!
采纳的回答
Torsten
2015-10-9
1. ydata has to be an array of the same size as xdata (I don't know the size of the array beta).
2. The call to nlinfit must read
y = nlinfit(xdata,ydata,@fun,beta0);
3. fun.m must read
function y = fun(beta0,xdata);
y = beta0(1)+ beta0(2)*exp(-xdata/beta0(3));
Best wishes
Torsten.
更多回答（1 个）
Walter Roberson
2015-10-9
y = beta0(1)+ beta0(2).*exp(-n/beta0(3));
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