how can the graph between x and y be extrapolated?

How can the graph between x and y be extrapolated?

x=linspace(140 230 10);
y=[54 60 70 76 86 100 112 130 152 180];

Find the value of y at x=0 and also extrapolate the graph until x=0.

[John D'Errico]

What have you tried? This is a nice, pretty smooth curve. So many things MIGHT yield some reasonable result. But what is reasonable? I suppose some methods might be more reasonable, but any extrapolation over a long distance will be suspect.

In general, extrapolation over a long distance requires that you postulate some intelligent model over that domain, otherwise, strange things CAN happen. The idea is you need to bring your understanding of the process into the result, else you may get garbage.

Make an effort. Think about the problem. What might be reasonable? If you cannot bother to do so, then why should we do your homework for you? You would learn nothing if we do.

[Star Strider]

If this is not homework, is there any reason for you to assume that the data exist at x=0?

What are your data? (What are the actual units of ‘x’ and ‘y’?)

What process produced them?

Do you have a mathematical model of the process that produced them?

[John D'Errico]

I'd be very surprised if this is not homework, lol. Possible though.

Answer 1

[John BG]

Parul

try

p=polyfit(x,y,3)

define the extended range x2, for instance

x2=linspace(100,600,10)

approximate vales of y along extended rage x2 with

y2=polyval(p,x2)

If you find this answer of any help solving your question, please click on the thumbs-up vote link,

thanks in advance

John

[e-mail]

note: since i don't know whether it's homework or not i assume it isn't

it's not that don't care, just don't consider asking appropriate.

if you consider it may be an attempt of homework piggy-backing, just say nothing and hop to next question.

It could be genuinely an attempt to unblock a problem, regardless homework or not.

It could be a student with poor command of English taking courage and asking to keep pace.

it's up to you to decide whether to help or not, if you try to gather 'intel'

they may stop asking, and you don't want that, do you?

does it make sense?