I have a procedure which give an approximate solution for ode.

This our procedure

RKadaptivestepsize := proc (f, a, b, epsilon, N).

It's working ( afther some 3 mistake found by a member in Mapleprime).

Then I would like to compute the error between exact and approximate.

RKadaptivestepsize: compute the approximate solution

analyticsol: analytic solution

## here, I compute the error

for N from 2 by 2 to 500 do

dataerror:= N->evalf(abs(RKadaptivestepsize(f,0,1,epsilon,N)[1+N][2]-(eval(analyticsol, x = 1))));

## sequence of data error

data[error] := [seq([N, dataerror(N)], N = 2 .. 500, 2)]:

if data[error][k][2]<=epsilon then

printf("%a is the number of steps required using 3-step Runge Kutta Method to achieve an eroor of 1e-6 .", k)

break ;

end if;

end do;

end do;

But its gives an error.: Error, reserved word `error` unexpected

Have any one an idea.