hi friends

i have a problem in maple with an error

dsnumsort:=proc(numpr::list,coor::list)

local i,j,n;

global C1,C2,C3,V1,V2,V3;

n:=nops(coor):

print("Order of the variables:");

for i from 2 to 2*n +1 do

for j from 1 to n do

if[numpr[i]]=

select(has,numpr,diff(coor[j](t),t)) then

C[j]:=i-1;V[j]:=i;

print(coor[j],C[j]," ",diff(coor[j](t),t),V[j]);

fi;

od;

od;

end :

Us:=subs(G=1,m=1,L=1,U):

D2r:=[diff(z(t),t,t),diff(x(t),t,t),diff(y(t),t,t)]:

g:=subs(z=z(t),x=x(t),y=y(t),grad(Us,[z,x,y])):

IniC:=z(0)=0.75,D(z)(0)=0, x(0)=1,D(x)(0)=0,y(0)=0,D(y)(0)=1:

Ns:=dsolve({seq(D2r[i]=g[i],i=1..3),IniC},{z(t),x(t),y(t)},numeric);

dsnumsort(Ns(0),[z,x,y]):

for i from 0 to 1000 do ;

T:=i/25;

NsT:=Ns(T):

X[i]:=rhs(NsT[C1]); Vx[i]:=rhs(NsT[V1]);

Y[i]:=rhs(NsT[C2]); Vy[i]:=rhs(NsT[V2]);

Z[i]:=rhs(NsT[C3]); Vz[i]:=rhs(NsT[V3]);

KepVec[i]:=convert(crossprod([X[i],Y[i], Z[i]],[Vx[i],Vy[i], Vz[i]]),list);

KepAbs[i]:=norm(KepVec[i],2);

od:

but i see this error and I can't draw PLOT:

Error, invalid input: rhs received Ns(0)[C1], which is not valid for its 1st argument, expr

this cods is for draw plot:

spacecurve({[seq([X[i], Y[i], Z[i]], i = 0 .. 1000)], [[-1/2, 0, 0], [1/2, 0, 0]]}, labels = ['x', 'y', 'z']);

spacecurve([seq(KepVec[i], i = 0 .. 1000)], orientation = [0, 90], labels = ['x', 'y', 'z'])

plot([seq([(1/25)*i, KepAbs[i]], i = 0 .. 1000)], labels = ['t', 'MofI'])

can you helpe me?Thank you