## 10 Reputation

9 years, 151 days

## MaplePrimes Activity

### These are replies submitted by bfathi

@acer You can help me? Please

## This is a university project...

This is a university project. The project is for book "Solving Problems in Scientific Computing Using Maple and MATLAB"

Thank you very much.

maple.txt

## Now I will send...

yes, Now I will send for you my Worksheet:

maybe you can help me

I wrote the code but i see very  errors

Thank you.

maple11_MAS94.mw

## yes. But i don't...

yes. But i don't what do I?

## This code is for orbit.sav...

@Mac Dude This code is for orbit.sav

Ns := dsolve({dx, dy, IniC}, {x(t), y(t)}, numeric):

tx := evalf((t1+t2)*(1/2)):
t1 := 326*40: t2 := 327*40:
y1 := rhs(Ns(t1)[c1]): y1 := rhs(Ns(t2)[c2]):
while(t1 < tx) and ( tx < t2) do
yx := rhs(Ns(tx)[c2]);
if yx > 0 then
y2 := yx: t2 := tx: else
y1 := yx: t1 := tx
fi
od:
Tx = evalf(tx);
Hx := floor((1/3600)*tx): Mx := floor((tx-3600*Hx)*(1/60)): Sx := tx-3600*Hx-60*Mx:
Hx, Mx, Sx;

But after this code i see this error:

Error, invalid input: rhs received Ns(13040)[c1], which is not valid for its 1st argument, expr
Error, invalid input: rhs received Ns(13080)[c2], which is not valid for its 1st argument, expr

## I've changed the code below...

@Mac Dude  I've changed the code below

> restart; read "orbit.sav ": with(plots):
> ax := -G*Mz*x/(x^2+y^2)^(3/2): ay := -G*Mz*y/(x^2+y^2)^(3/2):
j:=ix -> ix + 1;
for k from 0 to 3 do

x := 7*10^6: Vx := 0: y := 0: Vy := 9000: dt := evalf(1/2^k):

for i from 0 to 328 do

X[i] := evalf(x): Y[i] := evalf(y):

for n to 40*2^k do

x := evalf((1/2)*ax*dt^2+Vx*dt+x): y := evalf((1/2)*ay*dt^2+Vy*dt+y): Vx := evalf(ax*dt+Vx): Vy := evalf(ay*dt+Vy) end do:

if `mod`(i, 41) = 0 then

dX[k, i] := X[i]-XS[j]; dY[k, i] := Y[i]-YS[j] end if end do;

p[k] := plot([seq([(X[i]-XS[j])*(1/1000), (Y[i]-YS[j])*(1/1000)], i = 0 .. 328)], color = green) end do;

> C1 := display({seq(p[k], k = 0 .. 3)}, thickness = 3):

SI := [seq(41*i, i = 0 .. 8)]:

C2 := plot({seq([seq([(1/1000)*dX[k, i], (1/1000)*dY[k, i]], k = 0 .. 1), [0, 0]], i = SI)}, color = black):

display({C1, C2}, scaling = constrained, labels = ['dx', 'dy']);

display({C1, C2}, view = [-.1 .. .5, -.4 .. .2], scaling = constrained, labels = ['dx', 'dy']);

But i see this errors:

1)display({display({p[0], p[1], p[2], p[3]}, thickness = 3),

INTERFACE_PLOT(CURVES([[0., 0.]]), CURVES([[0., 0.]]),

CURVES([[0., 0.]]), CURVES([[0., 0.]]), CURVES([[0., 0.]]),

CURVES([[0., 0.]]), CURVES([[0., 0.]]), CURVES([[0., 0.]]),

CURVES([[0., 0.]]), COLOUR(RGB, 0., 0., 0.),

AXESLABELS("", ""), VIEW(DEFAULT, DEFAULT))},

scaling = constrained, labels = [dx, dy])

2)display({display({p[0], p[1], p[2], p[3]}, thickness = 3),

INTERFACE_PLOT(CURVES([[0., 0.]]), CURVES([[0., 0.]]),

CURVES([[0., 0.]]), CURVES([[0., 0.]]), CURVES([[0., 0.]]),

CURVES([[0., 0.]]), CURVES([[0., 0.]]), CURVES([[0., 0.]]),

CURVES([[0., 0.]]), COLOUR(RGB, 0., 0., 0.),

AXESLABELS("", ""), VIEW(DEFAULT, DEFAULT))},

view = [-0.1 .. 0.5, -0.4 .. 0.2], scaling = constrained,

labels = [dx, dy])

Excuse me

Thank you

## my plot...

@Preben Alsholm picuter1.jpg is the result we want and show in book

but pictuer2.png is the plot that we see with your algurithm

this code is in maple 14

## @Preben Alsholm OK. Unfortunat...

@Preben Alsholm OK. Unfortunately your  algorithm did not draw my plots.

## @Rouben Rostamian   This algorithm ...

This algorithm is Before this codes:

> restart;
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 :

## @Preben Alsholm This algorithm is B...

@Preben Alsholm This algorithm is Before this codes:

> restart;
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 :

## maple...

@Carl Love Can you help me please?

## problem...

@Carl Love hi friend

i have another error in solving problem in that section .... as you can see in picture i attach ... in "Ns proc" my answer is inverses from book .... after this in reading "dsnumsort" proc that variables are moved to the book  ... can you help me in this problem ?

## maple...

@Carl Love thanks alot for your time and support :)

 1 2 Page 1 of 2
﻿