First and second order ODE examples.



I do not know how to solve them in one step like. How to put sets - {} in the command?

>dsolve({D(y)(x)=x-y,y(0)=1},y(x))

Could someone give some help?

Regards,
Radovan

---

ode2.sm (13 КиБ) скачан 176 раз(а).

Updated. The document can not be saved. I don't know why.

plot([`in`[1], `in`[2], t=0..2*Pi], color=blue );

plot3d( `in`, x=-5..5, y=-5..5, scaling=constrained, style=patch,
orientation=[40,50], grid=[50,50], color=gray, axes=frame,
lightmodel=`light4`, projection=`normal`, shading=zgrayscale );

implicitplot3d( `in`=0, x=-2..2, y=-2..2, z=-2..2, grid=[50,50,50], orientation=[20,60],
axes=frame, lightmodel=`light4`, projection=`normal`, style=patchnogrid);



F:=implicitplot3d( `in`[1]=0, x=-2..2, y=-2..2, z=-2..2, grid=[30,30,30],
style=patchnogrid ):

G:=plot3d(`in`[2], x=-2..2, y=-2..2, style=patch, color=white):

display({F,G}, orientation=[20,60], axes=box, lightmodel=`light2`,
projection=`normal`, labels=["X","Y","Z"], scaling=constrained,
tickmarks=[4,4,4] );




[MATH]f(x;y;z)a^2*(x^2+y^2+z^2))^{-2}+(b^8*(x^8+y^8+z^8))^4-2[/MATH]

F:=implicitplot3d( `in`=0, x=-2.1..2.1, y=-2.1..2.1, z=-2.1..2.1,
grid=[50,50,50], style=patchnogrid ):

display({F}, orientation=[35,55], axes=box, lightmodel=`light4`,
projection=`normal`, labels=["X","Y","Z"], scaling=constrained,
tickmarks=[4,4,4] );

Wrote

I do not know how to solve them in one step like. How to put sets - {} in the command?

>dsolve({D(y)(x)=x-y,y(0)=1},y(x))

Could someone give some help?

Aha,...convert() was the magic word. Thank you
Strange, but this one was the only one successful



My other attempts in making plots and reproducing your pictures, issued an error about missing gif file in tmp folder. See the picture please



The problem of not saving pictures and SMat crash still remained.

Regards,
Radovan

Show me the log file: mvr5.txt.

Wrote

Show me the log file: mvr5.txt.

Here it is. If you want me something in particular to try, just let me know.

Regards,
Radovan

---

mvr5.txt (192 КиБ) скачан 149 раз(а).

This one is after deleting mvr5.txt and trying to make a parametric 3dplot

---

Wrote

Wrote

Show me the log file: mvr5.txt.

Here it is. If you want me something in particular to try, just let me know.

Regards,
Radovan

Radovan, you have to change the maple-commands for each graph. In your example these commands are set incorrectly. I specifically show the commands. They need to be inserted into the settings form, as showed above.

1) Try this:

a := plot( `in`, t=0..20, x=-1.5..1.5, scaling=unconstrained, style=line,
color=blue, axes=box, labels=["t","x(t) "]):

b := coordplot(rectangular, [0..20, -1.5..1.5], linestyle=[7,7],
color=[gray,gray]):

display([a,b]);

2) projection=`normal must be projection=`normal`

I tried your suggestion (just copy/paste) and calculation take quite long (did not wait for it to finish). Just used the simple one, and it worked (the first picture). It is good enough for me .

Tried one of your examples, and typed carefully as much as I could. I did not see any mistake - but the plot did not appear (the second picture)



Regards,
Radovan

---

mvr5.txt (265 КиБ) скачан 138 раз(а).

Try to add with(plots): to with.inc:

Цитата

with(linalg):with(inttrans):with(plots):

Wrote

Try to add with(plots): to with.inc:

Цитата

with(linalg):with(inttrans):with(plots):

It worked . What was the catch?

---

Nice

---

ode2-boundary.sm (18 КиБ) скачан 187 раз(а).

MaplePlot updated. Small imprоvements.

Just to confirm. The EMPTY PLOT is now working fine. No crash of SMath at the plot inserting

Hello,

Heartily please for the prompt, how to check in Maple that two expressions are to themselves equal. For example whether the expression under variable a is such alone as the expression under variable b?

Regards,
Janusz

Wrote

Heartily please for the prompt, how to check in Maple that two expressions are to themselves equal. For example whether the expression under variable a is such alone as the expression under variable b?

I do not use maple to much (it is interesting and a fun using it in SMath ) , and someone else might give you a better solution - but this should work

[MATH=eng]e1a^2-1)*1/sqrt(a)[/MATH]

[MATH=eng]e2b-1)*(b+1)/sqrt(b)[/MATH]

[MATH=eng]maple(simplify(subs(a≡b,e1)-e2))=0[/MATH]

Regards,
Radoavn

Hi Radoavn,

Thank you, interesting solution, will try out it.

Regards,
Janusz

Updated. Still can't save region.

Показать спойлер

---

MaplePlot. Example 8.sm (4 КиБ) скачан 193 раз(а).

Thanks for the update.

I have still trouble with the basics. Example 2 does not work.

Here is what the log file says:

Показать спойлер

There are empty tmp files in the tmp dir:
tmp59BF.tmp
tmp5A0F.tmp

In your example:
[MATH]`in`x^2+y^2+z^2)-1[/MATH]

but expected:

[MATH]sys(el(`in`;1);el(`in`;2);2;1):sys((x^2+y^2+z^2)-1;0;2;1)[/MATH]

we get: `in`[1]="" , `in`[2]="" - empty values (because it is not a system) and `in`=(x^2+y^2+z^2)-1 (but is missing in script)

Must be:

Показать спойлер

Цитата

There are empty tmp files in the tmp dir:
tmp59BF.tmp
tmp5A0F.tmp

This is normal.