# Question:fprintf help

## Question:fprintf help

Maple
Hi, I'm trying to get maple to output the numerical answer, from a call to dsolve, to an external txt file; but I'm having a bit of trouble. I want to do this so that I may then plot the results in an external program like easy-plot, or just analyse them. I'm using a "read" command in Maple to read in a procedure from a txt file (shown below), which I then execute in Maple: #Utilise prime notation for derivatives wrt t: with(PDEtools, declare): with(plots): declare(y(t), prime=t, quiet): #Also shorten output notation: alias(y=y(t),y0=y(0),yp0=D(y)(0)): #define the ODE: ODE:=diff(y,[t\$2])-(1-y^2)*diff(y,t)+y=0; #Define interval: ini:=y0=0, yp0=-0.1: IVP:= {ODE, ini}: #procedure - get1: get1:=proc() #Declare variables: global F: #Open file to print numerical answer to: fd := fopen(testfile,WRITE,TEXT): #Find numerical solution of system of differential equations: F:=dsolve(IVP, y, numeric, output=procedurelist, abserr=1e-13,relerr=1e-13); fprintf(%a\n , F); #Close file: fclose(fd): #end procedure: end proc: My problem comes from not knowing what code to use in the fprint command so that I get back a tabulated set of data that can be read by easy-plot/excel etc. Do I have to implicitly call for "output=array", and then define the points over which I want the data from, or is there some easer way to go about what I'm after? (If that makes any sense :-) ) Please help! Steve
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