fitting of a curve containing definite integration

[mjaugustin]

I  want to fit a curve of the equation T=(1/(SQRT(pi*q))* intgral (-10 to +10)[(1+q * exp(-a*t^2)*dt

[altenbach]

Use the nonliner curve fit with the VI model mode.

You need to create a model VI from the template (check the online help). It should calculate an array of T for an array of independent variables, given the parameters.

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mjaugustin wrote:
I  want to fit a curve of the equation T=(1/(SQRT(pi*q))* intgral (-10 to +10)[(1+q * exp(-a*t^2)*dt

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You need to be more specific. What  are the fitting paramters? What are constants? What is the independent variable?

[mjaugustin]

Thanks a lot for your kind reply.

Actualy the  variables in the equation is calculated using other equations.Suppose q is fitting parameter all other are known ,I want to know how to do the integration from -10 to +10.Would you please help me

with regards

augustin 

[altenbach]

I am still confused what your "x" is?

You could just calcualte an array of values for t=-10..10 of sufficient density and the feed it to "numeric integration" to get the integral.

(My analytical math is a bit rusty, but maybe there is also an analytical solution for the integral. Maybe I 'll try Maple when I get a chance) ;).

[altenbach]

Could you also correct your formula. The brackets don't match up.

[Joseph_Loo]

I believe the definite integral of 1+ q*exp(-at^) is (sqrt(pi)*q*erf(sqrt(a*t))/2* sqrt(a))+t

[mjaugustin]

thank u  now i think i can do the thing ..i willl send you  the result

have a nice day

warm regards

augustinmj