7 Feb 16:06 2008

### Re: numerical evaluation of psi0

```Barton Willis wrote:
> I evaluated psi[0](1.78095) using  webMathematica, Maple 10, and Maxima
> 5.14.0 to 50
> digits:
>
> Created by webMathematica
> 0.27085244394958037219241274879122247322668078991599
> Maple
> 0.27085617938915025987352993092362827661833339343790
> Maxima
> 0.2708561793891502598735299309236282766183333934379b-1
>
> (1) What's the story?

You mean that Mma returns something different?  I think you need to say
1.780950000<lots more zeroes>0.  Something about how mma does some kind
of significance arithmetic or something.  I get something close to
Maple's value then.

>
> (2) Does anybody have a reference to how our psi function works? It
> seems to use a modified asymptotic expansion.

I looked at bffac a while back that is the asymptotic series for log
gamma.  A peek at bfpsi shows that it is probably also the asymptotic
series for psi.  Probably A&S 6.3.18.

(We should document these routines.)
>
> (3) Does our psi function work in the complex plane? --- you do need
```

7 Feb 16:43 2008

### Re: numerical evaluation of psi0

maxima-bounces <at> math.utexas.edu wrote on 02/07/2008 09:06:39 AM:

> Barton Willis wrote:
> > I evaluated psi[0](1.78095) using  webMathematica, Maple 10, and Maxima
> > 5.14.0 to 50

> You mean that Mma returns something different?

When I re-did the Mma calculation, all three values agreed. Sorry about that.

> > (2) Does anybody have a reference to how our psi function works? It
> > seems to use a modified asymptotic expansion.

> I looked at bffac a while back that is the asymptotic series for log
> gamma.  A peek at bfpsi shows that it is probably also the asymptotic
> series for psi.  Probably A&S 6.3.18.

I think there is a clever modification of 6.3.18. If I figure it out, I'll
append a comment. Let's see if we can tweak bfpsi0 to work better in the
complex plane...

Barton
```_______________________________________________
Maxima mailing list
Maxima <at> math.utexas.edu
http://www.math.utexas.edu/mailman/listinfo/maxima
```
7 Feb 22:06 2008

### request for help getting maxima to plot the like i would want

```Hello everybody,

I have been using and developing linux for 3 years and am an experienced
user. I am following some basic mathematical classes on my university.
In this collage I have to use software to calculate and analyze
functions. The software that is used is called Derive:
http://en.wikipedia.org/wiki/Derive_computer_algebra_system

For a real FLOSS user this is not an option, so I went trying out all
the mathematical tools for GNU/Linux. I think maxima is the program that
should be able to do all the calculations and visualisations on the
functions I use. However after spending a day working and trying I cant
get my functions to plot the way I want and to calculate on them
(differentiations / Integration / Compare / Solve).

I tried to do somethings but its not working out very well.

Would somebody be willing to help me out, and demonstrate the command
required to be able to plot in almost exactly the same way as the 2
example pages with the plots, that I included as attachment. (see this

Kind regards,

Jelle

Formulas and things i was working on:

f(z):=-x-y+5;
f(z):=9-x^2-Y^2;
f(z):=5-x^2;

f(z):=-2*x-y+4;
f(z):=-x-3*y+6;
f(z):=x+y-4;

f(z):=x^2+y^2=r^2;
r:3;

f(z0):=0=y-x^2;
f(z1):=1=y-x^2;
f(z4):=4=y-x^2;

solve(f(z0));

f(z):=5-x^2;
plot2d(f(z),[x,-6,6],[y,-6,6],[xlabel,"X"],[ylabel,"Y"],[gnuplot_preamble,"set

xzeroaxis;set yzeroaxis;unset border;set xtics"]);

plot3d(f(z),[x,-6,6],[y,-6,6]);
```
7 Feb 22:08 2008

### request for help getting maxima to plot the like i would want (correct link)

```Hello everybody,

I have been using and developing linux for 3 years and am an experienced
user. I am following some basic mathematical classes on my university.
In this collage I have to use software to calculate and analyze
functions. The software that is used is called Derive:
http://en.wikipedia.org/wiki/Derive_computer_algebra_system

For a real FLOSS user this is not an option, so I went trying out all
the mathematical tools for GNU/Linux. I think maxima is the program that
should be able to do all the calculations and visualisations on the
functions I use. However after spending a day working and trying I cant
get my functions to plot the way I want and to calculate on them
(differentiations / Integration / Compare / Solve).

I tried to do somethings but its not working out very well.

Would somebody be willing to help me out, and demonstrate the command
required to be able to plot in almost exactly the same way as the 2
example pages with the plots, that I included as attachment. (see this

Kind regards,

Jelle

Formulas and things i was working on:

f(z):=-x-y+5;
f(z):=9-x^2-Y^2;
f(z):=5-x^2;

f(z):=-2*x-y+4;
f(z):=-x-3*y+6;
f(z):=x+y-4;

f(z):=x^2+y^2=r^2;
r:3;

f(z0):=0=y-x^2;
f(z1):=1=y-x^2;
f(z4):=4=y-x^2;

solve(f(z0));

f(z):=5-x^2;
plot2d(f(z),[x,-6,6],[y,-6,6],[xlabel,"X"],[ylabel,"Y"],[gnuplot_preamble,"set

xzeroaxis;set yzeroaxis;unset border;set xtics"]);

plot3d(f(z),[x,-6,6],[y,-6,6]);
```
7 Feb 23:29 2008

### Re: request for help getting maxima to plot the like i would want

```Jelle de Jong escribiÃ³:
> Hello everybody,
>
> I have been using and developing linux for 3 years and am an experienced
> user. I am following some basic mathematical classes on my university.
> In this collage I have to use software to calculate and analyze
> functions. The software that is used is called Derive:
> http://en.wikipedia.org/wiki/Derive_computer_algebra_system
>
> For a real FLOSS user this is not an option, so I went trying out all
> the mathematical tools for GNU/Linux. I think maxima is the program that
> should be able to do all the calculations and visualisations on the
> functions I use. However after spending a day working and trying I cant
> get my functions to plot the way I want and to calculate on them
> (differentiations / Integration / Compare / Solve).
>
> I tried to do somethings but its not working out very well.
>
> Would somebody be willing to help me out, and demonstrate the command
> required to be able to plot in almost exactly the same way as the 2
> example pages with the plots, that I included as attachment. (see this
>

Hello,

You can try this code with Maxima 5.14:

draw3d(implicit(z=-x-y+5, x,0,5, y,0,5, z,0,5))\$

draw3d(surface_hide = true,
implicit(z=9-x^2-y^2, x,-4,4, y,-4,4, z,0,10))\$

/*
Define the parametric curve:
x=t,
y=2,
z=5-t^2
*/
draw3d(parametric(t,2,5-t^2, t,-5,5))\$

--

--
Mario Rodriguez Riotorto
www.biomates.net
```
7 Feb 22:04 2008

### request for help getting maxima to plot the like i would want

```Hello everybody,

I have been using and developing linux for 3 years and am an experienced
user. I am following some basic mathematical classes on my university.
In this collage I have to use software to calculate and analyze
functions. The software that is used is called Derive:
http://en.wikipedia.org/wiki/Derive_computer_algebra_system

For a real FLOSS user this is not an option, so I went trying out all
the mathematical tools for GNU/Linux. I think maxima is the program that
should be able to do all the calculations and visualisations on the
functions I use. However after spending a day working and trying I cant
get my functions to plot the way I want and to calculate on them
(differentiations / Integration / Compare / Solve).

I tried to do somethings but its not working out very well.

Would somebody be willing to help me out, and demonstrate the command
required to be able to plot in almost exactly the same way as the 2
example pages with the plots, that I included as attachment.

Kind regards,

Jelle

Formulas and things i was working on:

f(z):=-x-y+5;
f(z):=9-x^2-Y^2;
f(z):=5-x^2;

f(z):=-2*x-y+4;
f(z):=-x-3*y+6;
f(z):=x+y-4;

f(z):=x^2+y^2=r^2;
r:3;

f(z0):=0=y-x^2;
f(z1):=1=y-x^2;
f(z4):=4=y-x^2;

solve(f(z0));

f(z):=5-x^2;
plot2d(f(z),[x,-6,6],[y,-6,6],[xlabel,"X"],[ylabel,"Y"],[gnuplot_preamble,"set
xzeroaxis;set yzeroaxis;unset border;set xtics"]);

plot3d(f(z),[x,-6,6],[y,-6,6]);
```
```_______________________________________________
Maxima mailing list
Maxima <at> math.utexas.edu
http://www.math.utexas.edu/mailman/listinfo/maxima
```
8 Feb 13:30 2008

### Re: request for help getting maxima to plot the like i would want

```Mario Rodriguez wrote:
> Jelle de Jong escribiÃ³:
>> Hello everybody,
>>
>> I have been using and developing linux for 3 years and am an experienced
>> user. I am following some basic mathematical classes on my university.
>> In this collage I have to use software to calculate and analyze
>> functions. The software that is used is called Derive:
>> http://en.wikipedia.org/wiki/Derive_computer_algebra_system
>>
>> For a real FLOSS user this is not an option, so I went trying out all
>> the mathematical tools for GNU/Linux. I think maxima is the program that
>> should be able to do all the calculations and visualisations on the
>> functions I use. However after spending a day working and trying I cant
>> get my functions to plot the way I want and to calculate on them
>> (differentiations / Integration / Compare / Solve).
>>
>> I tried to do somethings but its not working out very well.
>>
>> Would somebody be willing to help me out, and demonstrate the command
>> required to be able to plot in almost exactly the same way as the 2
>> example pages with the plots, that I included as attachment. (see this
>>
>
> Hello,
>
> You can try this code with Maxima 5.14:
>
>
> draw3d(implicit(z=-x-y+5, x,0,5, y,0,5, z,0,5))\$
>
> draw3d(surface_hide = true,
>       implicit(z=9-x^2-y^2, x,-4,4, y,-4,4, z,0,10))\$
>
> /*
> Define the parametric curve:
> x=t,
> y=2,
> z=5-t^2
> */
> draw3d(parametric(t,2,5-t^2, t,-5,5))\$
>
>

Hi Mario,

Thank you for your help, I compiled the latest maxima and have been

However I am still unable to get an X-ax and Y-Ax in the middle:

Y
|
|
----------- X
|
|

I have been trying the following input, however I cant get it right.

I got a function that I substitute with an other function creating a new
function that I want to plot. I think I really need a good document with
examples how to port math that you do with your hands and head to
something I can enter in maxima.

function: z=y-x^2;
function, z=4;
solve(%,y);
plot2d(%,[x,-10,10]);

f1: 4;
f2: y-x^2;
solve(f1=f2,y);
draw2d(explicit(%,x,-6,6));

Kind regards,

Jelle
```
8 Feb 16:20 2008

### Problem with "globalsolve:true"

```
Hi,

Does anybody understand why K2 in the following script is not solved global?
What am I doing wrong? In my opinion the last line should be:
M(z)=z*A-(q*z^2)/2

(%i1) M(z)::=K2+A*z-q*z^2/2;
(%o1) M(z)::=K2+A*z+((-q)*z^2)/2

(%i2) globalsolve:true\$

(%i3) solve([M(z)=0,z=0],[K2,z]);
(%o3) [[K2=0,z=0]]

(%i4) display(M(z))\$

M(z)=K2+z*A-(q*z^2)/2
```
8 Feb 16:28 2008

### Re: request for help getting maxima to plot the like i would want

```Hello,

> Hi Mario,
>
> Thank you for your help, I compiled the latest maxima and have been
>
> However I am still unable to get an X-ax and Y-Ax in the middle:
>
>       Y
>       |
>       |
> ----------- X
>       |
>       |
>
> I have been trying the following input, however I cant get it right.
>

This is an (baroque) example showing options related to axis in 3d (you
probably won't need to use all of them!):

draw3d(
xaxis=true, xaxis_color = red, xaxis_type=solid, xaxis_width=2,
yaxis=true, yaxis_color = aquamarine, yaxis_type=solid,
yaxis_width=4,
zaxis=true, zaxis_color = "#ff25cb", zaxis_type=dots, zaxis_width=6,
xrange = [-1,6], yrange = [-1,6], zrange = [-1,6],
xlabel = "Athos", ylabel = "Portos", zlabel = "Aramis",
user_preamble= "set xyplane at 0",
implicit(z=-x-y+5, x,0,5, y,0,5, z,0,5));

> f1: 4;
> f2: y-x^2;
> solve(f1=f2,y);
> draw2d(explicit(%,x,-6,6));
>
Note in this example that %[1] is the 1st component of the list returned
by solve, which is an equation, and rhs returns its right hand side:

f1: 4;
f2: y-x^2;
solve(f1=f2,y);
draw2d(explicit(rhs(%[1]),x,-6,6));

hth

--

--
Mario Rodriguez Riotorto
www.biomates.net
```
8 Feb 16:50 2008

### Re: Problem with "globalsolve:true"

```globalsolve does not redefine functions.  You seem to be using much more
complicated syntax and ideas than needed. Also you should use linsolve
if you want to have globalsolve work. Solve on systems apparently
ignores globalsolve, perhaps because algebraic systems may have many
solutions... which should be assigned globally>

Try

M:  K2+A*z-q*z^2/2;
globalsolve:true;

linsolve([M=0,z=0],[K2,z]);

ev(M);

or just substituting z=0 in Helge Hansen wrote:
> Hi,
>
> Does anybody understand why K2 in the following script is not solved global?
> What am I doing wrong? In my opinion the last line should be:
> M(z)=z*A-(q*z^2)/2
>
> (%i1) M(z)::=K2+A*z-q*z^2/2;
> (%o1) M(z)::=K2+A*z+((-q)*z^2)/2
>
> (%i2) globalsolve:true\$
>
> (%i3) solve([M(z)=0,z=0],[K2,z]);
> (%o3) [[K2=0,z=0]]
>
> (%i4) display(M(z))\$
>
> M(z)=K2+z*A-(q*z^2)/2
>
>
>
> _______________________________________________
> Maxima mailing list
> Maxima <at> math.utexas.edu
> http://www.math.utexas.edu/mailman/listinfo/maxima
>
```

Gmane