mathlib-develop — This is a mailing list for discussing the development of the JMathLib program.

Re: [Mathlib-develop] Path Function & problems with funcion calls

[Stefan M. <st...@he...>]

mark wrote:
> On Thursday 20 Feb 2003 7:40 pm, Stefan Mueller wrote:
> 
>>>While testing it I notived a problem with function calls
>>>
>>>entering
>>>
>>>
>>>>path
>>>
>>>runs the path function and sets the ans variable but doesn't display
>>>anything
>>>
>>>while entering
>>>
>>>
>>>>path()
>>>
>>>displays the result of the function call.
>>
>>I'll have a look into it.
>>
>>Kind regards,
>>   Stefan.
> 
> 
> 
> This seems to be connected to the function being treated as a variable rather 
> than a function when the brackets are ommitted.
> 
> There is a similar problem if there is a space between the function name and 
> the brackets. If you enter
> 
>>sin (5)
> 
> 
> then you get a null pointer error.
> 
> After checking it seems that MathLib treats VariableTokens and FunctionTokens 
> in the same way. It first checks for a variable with that name then for a 
> function.
> 
> Therefore it might be an idea to combine VariableTokens and FunctionTokens 
> into one class (Say ReferenceToken) since this would ensure consistent 
> behaviour regardless of how the function or variable is entered.
> 
> One difficulty is the fact that VariableToken descends from OperandToken while  
> FunctionToken descends from OperatorToken. RefereenceToken would have to be a 
> subclass of OperandToken which would mean that it would have to store any 
> parameters being passed to the variable or function.
> 
> Though this would have the advantage of making functions more consistent with 
> keyword functions such as IF and WHILE.

You're right, the mentioned approach looks very nice. There is also
another advantage. To move functions into a descendent of OperandToken
would clean up the handling of Expression-Tokens. In the future
expression-tokens should only handle operands like +,*/^   this will
simplify handling of priorities and evaluation of expressions.

I'll start working on it right away. I propose to call the new
token FunctionVariable-token since it cannot be determined during
parsing if a token is a variable or a function.

Kind regards,
   Stefan.

Re: [Mathlib-develop] Path Function & problems with funcion calls

[mark <msp...@ya...>]

On Thursday 20 Feb 2003 7:40 pm, Stefan Mueller wrote:
> > While testing it I notived a problem with function calls
> >
> > entering
> >
> >>path
> >
> > runs the path function and sets the ans variable but doesn't display
> > anything
> >
> > while entering
> >
> >>path()
> >
> > displays the result of the function call.
>
> I'll have a look into it.
>
> Kind regards,
>    Stefan.


This seems to be connected to the function being treated as a variable ra=
ther=20
than a function when the brackets are ommitted.

There is a similar problem if there is a space between the function name =
and=20
the brackets. If you enter
>sin (5)

then you get a null pointer error.

After checking it seems that MathLib treats VariableTokens and FunctionTo=
kens=20
in the same way. It first checks for a variable with that name then for a=
=20
function.

Therefore it might be an idea to combine VariableTokens and FunctionToken=
s=20
into one class (Say ReferenceToken) since this would ensure consistent=20
behaviour regardless of how the function or variable is entered.

One difficulty is the fact that VariableToken descends from OperandToken =
while =20
FunctionToken descends from OperatorToken. RefereenceToken would have to =
be a=20
subclass of OperandToken which would mean that it would have to store any=
=20
parameters being passed to the variable or function.

Though this would have the advantage of making functions more consistent =
with=20
keyword functions such as IF and WHILE.

Best Regards

Mark

[Mathlib-develop] Missing Files for SymbolicToken

[Stefan M. <st...@he...>]

Hi Mark,

there are a couple of files missing.
Please see below,

kind regards,
   Stefan.

.\MathLib\Tokens\SymbolicToken.java:300: cannot resolve symbol
symbol  : class GeometricSymbolicExpression
location: class MathLib.Tokens.SymbolicToken
             result = new GeometricSymbolicExpression(this);
                          ^
.\MathLib\Tokens\SymbolicToken.java:337: cannot resolve symbol
symbol  : class GeometricSymbolicExpression
location: class MathLib.Tokens.SymbolicToken
                 result = new GeometricSymbolicExpression(this);
                              ^
.\MathLib\Tokens\SymbolicToken.java:343: cannot resolve symbol
symbol  : class GeometricSymbolicExpression
location: class MathLib.Tokens.SymbolicToken
             result = new GeometricSymbolicExpression(this);
                          ^
.\MathLib\Tokens\SymbolicToken.java:372: cannot resolve symbol
symbol  : class ExponentialSymbolicExpression
location: class MathLib.Tokens.SymbolicToken
             result = new ExponentialSymbolicExpression(this, arg);
                          ^
17 errors

C:\CVSWork\mathlib\Source>javac -classpath ;. -d ..\Classes 
MathLib\Tokens\*.jav
a
MathLib\Tokens\FunctionToken.java:78: cannot resolve symbol
symbol  : class SymbolicExpression
location: class MathLib.Tokens.FunctionToken
             if(result == null && ((operands[0] instanceof 
SymbolicToken) ||(oper
ands[0] instanceof SymbolicExpression)))

                    ^
MathLib\Tokens\FunctionToken.java:80: cannot resolve symbol
symbol  : class FunctionSymbolicExpression
location: class MathLib.Tokens.FunctionToken
                 result = new FunctionSymbolicExpression(this, operands);
                              ^
MathLib\Tokens\NumberToken.java:498: cannot resolve symbol
symbol  : class SymbolicExpression
location: class MathLib.Tokens.NumberToken
         else if((arg instanceof SymbolicToken) || (arg instanceof 
SymbolicExpres

Re: [Mathlib-develop] Path Function & problems with funcion calls

[Stefan M. <st...@he...>]

> While testing it I notived a problem with function calls
> 
> entering
> 
>>path 
> 
> runs the path function and sets the ans variable but doesn't display anything
> 
> while entering
> 
>>path()
> 
> displays the result of the function call.
I'll have a look into it.

Kind regards,
   Stefan.

-- 
------------------------------------
Dr.-Ing. Stefan Mueller
email: St...@he...
------------------------------------

Re: [Mathlib-develop] Should NumberToken be immutable?

[mark <msp...@ya...>]

On Wednesday 12 Feb 2003 1:13 pm, mark wrote:
> At the moment when executing num1 <op> num2 the system sometimes modifi=
es
> num1 and sometimes creates a new NumberToken.
>
> I've been thinking that it might be better if NumberTokens were immutab=
le
> so that all operations returned a new object without changing either
> operand.
>

I've made the changes to NumberToken so that all operations should create=
 a=20
new instance.

If an operation ever modifies one of it parameters then that should be=20
considered to be a bug.

Best Regards

Mark

Re: [Mathlib-develop] Swing interface

[mark <msp...@ya...>]

On Monday 10 Feb 2003 4:58 pm, mark wrote:
> Hi Stefan and Alejandro
>
> I've noticed an error with the swing interface. It's stripping off the =
last
> character of any expression so that 12 + 34 becomes just 12 + 3
>

That's working correctly now.

Though I'm not getting any icon. The smalllogo.gif file is in the Swing=20
directory but it isn't appearing.

Best Regards

Mark

[Mathlib-develop] Path Function & problems with funcion calls

[mark <msp...@ya...>]

I've changed the path function so that it's an internal function defined =
in=20
the StandardFunction.java file.

I've done this so that if the search path is corrupted it is still possib=
le to=20
use the path function in order to check what state the search path is in.

While testing it I notived a problem with function calls

entering
>path=20
runs the path function and sets the ans variable but doesn't display anyt=
hing

while entering
>path()
displays the result of the function call.


Best Regards

Mark

Re: [Mathlib-develop] Re: Symbolic calculations

[mark <msp...@ya...>]

On Saturday 15 Feb 2003 10:04 pm, Alejandro Torras wrote:
> Hi Mark and Stefan!!
>
> > > Actually I meant finding factors of polynomials
> > > i.e. x^2 + 2*x + 1 =3D> (x+1)^2
> > >
> > > Though I'll check the link out since the the current implementation=
 of
> > > numerical factorization is pretty slow.
> >
> > Sorry, I've no clue at all. I've never done anything with symbolic
> > stuff.
>
> Me too, but I think we can give us hints to a proper sollution, as we h=
ave
> done before ;-)
>
> Finding the roots of polynomials, I have read something about the
> Tartaglia's triangle, Pascal's or Newton's one, but I don't remeber now=
=2E
>
> You can see a plenty tutorial about it at
> http://www.krysstal.com/binomial.html
>
> But this works only for binomial power of expressions like (x + y)^z wh=
ere
> x,y are integers and z is a natural number.
>
> If we want general root finding, including complex roots, we should sea=
rch
> a bit more.
>
> Regards,
> Alejandro.
>

Well I'm not sure that we need to worry about complex roots to begin with=
 but=20
it does need to be more general than just binomial expansions. Things lik=
e

x^3 + 6x^2 + 11x + 6 =3D (x+1)(x+2)(x+3)

I wasn't able to find anything on google but there is a section on it in=20
volume 2 of The Art Of  Computer Programming. I'll read through that toda=
y.

Best Regards

Mark

[Mathlib-develop] Re: Bug in SwingGui

[Alejandro T. <ate...@ho...>]

Hi Stefan!

I'm sorry I haven't reply you before.

This field is available since jdk 1.4.0.

I ported the swing gui to this version because I had some problems mixing
light and heavy weight components (popups) with 1.3.1.

You can take a look at Source/MathLib/UI/Swing/releasenotes.txt . I think
the upload was successful... Almost every choice I do is explained here.

Best regards,
Alejandro.

----- Original Message -----
From: "Stefan Mueller" <st...@he...>
To: "MathLib Devel" <mat...@li...>; "Alejandro
Torras" <ate...@ho...>
Sent: Thursday, February 13, 2003 5:24 PM
Subject: [Mathlib-develop] Bug in SwingGui


> Hi Alejandro,
>
> 1. did you also subscribe to the developer list? I also sent this email
>     to you standard address.
>
> 2. there's a bug in the Swing GUI
>
> MathLib\UI\Swing\Console.java:35: cannot resolve symbol
> symbol  : variable BUTTON2
> location: class java.awt.event.MouseEvent
>                  if  ((b & me.BUTTON2) == me.BUTTON2)
>                              ^
> MathLib\UI\Swing\Console.java:35: cannot resolve symbol
> symbol  : variable BUTTON2
> location: class java.awt.event.MouseEvent
>                  if  ((b & me.BUTTON2) == me.BUTTON2)
>                                             ^
> MathLib\UI\Swing\Console.java:39: cannot resolve symbol
> symbol  : variable BUTTON1
> location: class java.awt.event.MouseEvent
>                  else if ((b & me.BUTTON1) == me.BUTTON1)
>                                  ^
> MathLib\UI\Swing\Console.java:39: cannot resolve symbol
> symbol  : variable BUTTON1
> location: class java.awt.event.MouseEvent
>                  else if ((b & me.BUTTON1) == me.BUTTON1)
>                                                 ^
> 5 errors

[Mathlib-develop] Re: Symbolic calculations

[Alejandro T. <ate...@ho...>]

Hi Mark and Stefan!!

> > Actually I meant finding factors of polynomials
> > i.e. x^2 + 2*x + 1 => (x+1)^2
> >
> > Though I'll check the link out since the the current implementation of
> > numerical factorization is pretty slow.
> Sorry, I've no clue at all. I've never done anything with symbolic
> stuff.

Me too, but I think we can give us hints to a proper sollution, as we have
done before ;-)

Finding the roots of polynomials, I have read something about the
Tartaglia's triangle, Pascal's or Newton's one, but I don't remeber now.

You can see a plenty tutorial about it at
http://www.krysstal.com/binomial.html

But this works only for binomial power of expressions like (x + y)^z where
x,y are integers and z is a natural number.

If we want general root finding, including complex roots, we should search a
bit more.

Regards,
Alejandro.

Re: [Mathlib-develop] Re: Symbolic calculations

[mark <msp...@ya...>]

On Wednesday 12 Feb 2003 6:55 pm, Stefan Mueller wrote:
> >>Hi Mark and Stefan!
> >>
> >>1) Why don't we put it on a new class on Functions/Calculus package? =
I
> >> have free access to some "numerical methods" books at the university=
, so
> >> if you need it I'll pass you some hints.
> >
> > What I meant was how to handle cases like derivative( sin(x), x) =3D>
> > cos(x) or even derivative( UserFunction(x), x) =3D> OtherFunction(x)
> >
> > My idea was that the implementation of sin and UserFunction would con=
tain
> > a method called derivative which would return the correct value.
>
> I aggree to add the two methods to the individual functions.
> But what about complex integration/derivative rules, like the chain
> rule?
> e.g.: d/dx of sin(cos(x))
>

IIRC d/dx f(u) =3D d/dx u * d/du f(u)=20

so d/dx sin(cos(x)) =3D -sin(x) * cos(cos(x))

So differentiating chained functions shouldn't be too hard.

Though we should probably limit derivatives to functions that take 1=20
parameter.

Best Regards

Mark

[Mathlib-develop] Bug in SwingGui

[Stefan M. <st...@he...>]

Hi Alejandro,

1. did you also subscribe to the developer list? I also sent this email
    to you standard address.

2. there's a bug in the Swing GUI

MathLib\UI\Swing\Console.java:35: cannot resolve symbol
symbol  : variable BUTTON2
location: class java.awt.event.MouseEvent
                 if  ((b & me.BUTTON2) == me.BUTTON2)
                             ^
MathLib\UI\Swing\Console.java:35: cannot resolve symbol
symbol  : variable BUTTON2
location: class java.awt.event.MouseEvent
                 if  ((b & me.BUTTON2) == me.BUTTON2)
                                            ^
MathLib\UI\Swing\Console.java:39: cannot resolve symbol
symbol  : variable BUTTON1
location: class java.awt.event.MouseEvent
                 else if ((b & me.BUTTON1) == me.BUTTON1)
                                 ^
MathLib\UI\Swing\Console.java:39: cannot resolve symbol
symbol  : variable BUTTON1
location: class java.awt.event.MouseEvent
                 else if ((b & me.BUTTON1) == me.BUTTON1)
                                                ^
5 errors

-- 
------------------------------------
Dr.-Ing. Stefan Mueller
email: St...@he...
------------------------------------

[Mathlib-develop] mailing list

[Stefan M. <st...@he...>]

mark wrote:
> Hi Stefan and Alejandro

> Also now that the mailing list is set up what do you think to using that for 
> all discussion? It'll mean that all our insightful comments will be stored 
> for prosterity. 
I aggree. It's a good idea.

Kind regards,
   Stefan.

------------------------------------
Dr.-Ing. Stefan Mueller
email: St...@he...
------------------------------------

[Mathlib-develop] Re: Symbolic calculations

[Stefan M. <st...@he...>]

>>Hi Mark and Stefan!
>>
>>1) Why don't we put it on a new class on Functions/Calculus package? I have
>>free access to some "numerical methods" books at the university, so if you
>>need it I'll pass you some hints.
> 
> 
> What I meant was how to handle cases like derivative( sin(x), x) => cos(x) 
> or even derivative( UserFunction(x), x) => OtherFunction(x)
> 
> My idea was that the implementation of sin and UserFunction would contain a 
> method called derivative which would return the correct value.
I aggree to add the two methods to the individual functions.
But what about complex integration/derivative rules, like the chain
rule?
e.g.: d/dx of sin(cos(x))


>>2) Do you mean find the factors of a number (15= 3*5)
>>If true, this page can help you http://www.alpertron.com.ar/ECM.HTM
>>I have tried it with 128 digits on 16 segons!!!
> 
> 
> Actually I meant finding factors of polynomials 
> i.e. x^2 + 2*x + 1 => (x+1)^2
> 
> Though I'll check the link out since the the current implementation of 
> numerical factorization is pretty slow.
Sorry, I've no clue at all. I've never done anything with symbolic
stuff.

Kind regards,
   Stefan.

-- 
------------------------------------
Dr.-Ing. Stefan Mueller
email: St...@he...
------------------------------------

[Mathlib-develop] Should NumberToken be immutable?

[mark <msp...@ya...>]

At the moment when executing num1 <op> num2 the system sometimes modifies=
 num1=20
and sometimes creates a new NumberToken.

I've been thinking that it might be better if NumberTokens were immutable=
 so=20
that all operations returned a new object without changing either operand=
=2E

The advantages are
1: constants can be used in place of common numbers (-1,0,1,i)
2: this will reduce the need for functions to clone there parameters befo=
re=20
operating on them=20
3: it'll reduce the chance of bugs becuase of having two references to a=20
number that suddenly changes

The disadvantages are
1: It might slow some operations down

So what does everyone think about this?

Best Regards

Mark

[Mathlib-develop] New swing release

[Alejandro T. <ate...@ho...>]

Hi!

You can check out the new swing gui release.

There's two things to comment:
a) The swing gui has been developed and tested under the jdk 1.4.x, so =
it won't work properly on older versions (See releasenotes.txt - GN0004)

b) The context menu is still buggy (See GN0005)

Regards,
Alejandro.

[Mathlib-develop] Swing interface

[mark <msp...@ya...>]

Hi Stefan and Alejandro

I've noticed an error with the swing interface. It's stripping off the la=
st=20
character of any expression so that 12 + 34 becomes just 12 + 3

Also now that the mailing list is set up what do you think to using that =
for=20
all discussion? It'll mean that all our insightful comments will be store=
d=20
for prosterity.=20

Best Regards

Mark