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I am trying to incorporate the following equation into Matlab in the red:

http://http://www.radikal.ru][PLAIN]http://s018.radikal.ru/i518/1305/16/1cc0d2a72d38.jpg

The following data is to be used:

t=3000000

nr=nx=161

q=0.02

k=5e-13

mu=0.00035

c=1.5e-8

phi=0.25

rw=0.1

h=4.5

My code is below:

st=size(t)

nr=nx;

for i=1:1:st(1)

rd=r(1:nr)/wb

td=0.0036*k*t(i)/(phi*mu*c*wb^2)

pd=((pi*h*k)/(1.842*q*1.1*mu))*(IP-p(i,1:nr))

Ei_from_mfun=mfun('Ei',1,-rd^2/(4*td))

pd=1/2*Ei_from_mfun

plot(time,pd,'bo')

end

But it gives the following command :

"??? Index exceeds matrix dimensions."

Can you please help to fix the problem for every time, t and pressure,p?

Thanks

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# How to correctly code the expression with Ei function?

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