I am using 'fit' command for curve fitting. But my model equation is defined only for some range of input (x>5) . For x<5, model equation is y =2 (Having no constants). So How should I deal this problem ? Thanks in Advance.

I am using 'fit' command for curve fitting. But my model equation is defined only for some range of input (x>5) . For x<5, model equation is y =2 (Having no constants). So How should I deal this problem ? Thanks in Advance.

Answer 1

[John D'Errico]

You essentially have no model to fit, when x < 5. Even if you did, who cares? We already know what y is then! You know the model below that point. Any data that falls below x=5, just ignore it. It will not be needed for the fit, so there is no problem at all.