Theil-Sen estimator inorder to fit line

Hi,

I have attached a data file,consisting of two columns,with x and y data

and also the graph,I obtained with the data.

Red color->indicates the raw data

Green color-> indicates the Theil Sen Regression line

I would be really glad,if someone can check the below code and let me know the changes to be done,so that Theil sen regression line is fitted properly to the data.

I am exactly not sure,if the line equation would be in the form y = b*x, where b is the slope obtained from Theil Sen regression estimator.

I have written the following code:

data = load(textFile);
b = Thenil_Sen_Regress(data(:,1),data(:,2));
scatter(data(:,1),data(:,2),'r');
hold on;

plot(data(:,1),b*data(:,1),'g','LineWidth',3);

The function Theil_Sen_Regress() is as follows:

function b = Theil_Sen_Regress(x,y)

[N c]=size(x);
Comb = combnk(1:N,2);
deltay=diff(y(Comb),1,2);
deltax=diff(x(Comb),1,2);
theil=diff(y(Comb),1,2)./diff(x(Comb),1,2);
b=median(theil);