http://www.mapleprimes.com/questions/142714-Error-In-DEplot-The-number-Option en-us 2026 Maplesoft, A Division of Waterloo Maple Inc. Maplesoft Document System Tue, 16 Jun 2026 11:24:45 GMT Tue, 16 Jun 2026 11:24:45 GMT The latest answers and comments added to the Question, Error in DEplot the 'number' option must be specified before initial conditions http://www.mapleprimes.com/images/mapleprimeswhite.jpg http://www.mapleprimes.com/questions/142714-Error-In-DEplot-The-number-Option http://www.mapleprimes.com/questions/142714-Error-In-DEplot-The-number-Option?ref=Feed:MaplePrimes:Error in DEplot the 'number' option must be specified before initial conditions:Comments#answer142716 <p>You don't have a differential equation. Presumably you meant:</p> <p>DE := diff(y(t),t)=y(t)^2*(4-y(t)^2);</p> <p>&nbsp;</p> <p>The number option referred to is the number of equations in the first order system corresponding to your equation in your case 1. It applies only when the ode is given as a procedure:</p> <p>p:=proc(N,t,Y,YP) YP[1]:=Y[1]^2*(4-Y[1]^2) end proc;</p> <p>DEtools[DEplot]( p,y(t) ,t=0..1/2, number=1,{[y(0)=1],[y(0)=3]}, arrows=none, thickness=2, linecolor=[blue,green]);</p> <p>(see the help page for DEplot)</p> <p>You don't have a differential equation. Presumably you meant:</p> <p>DE := diff(y(t),t)=y(t)^2*(4-y(t)^2);</p> <p>&nbsp;</p> <p>The number option referred to is the number of equations in the first order system corresponding to your equation in your case 1. It applies only when the ode is given as a procedure:</p> <p>p:=proc(N,t,Y,YP) YP[1]:=Y[1]^2*(4-Y[1]^2) end proc;</p> <p>DEtools[DEplot]( p,y(t) ,t=0..1/2, number=1,{[y(0)=1],[y(0)=3]}, arrows=none, thickness=2, linecolor=[blue,green]);</p> <p>(see the help page for DEplot)</p> 142716 Mon, 28 Jan 2013 02:53:03 Z Preben Alsholm Preben Alsholm