UCALC equivalent

[Dark Cowherd]

http://www.ucalc.com/mathparser/index.html

There is a great library called UCALC which allows you to set up an
expression and evaluate it
for e.g. you an define an expression by calling a function in UCALC
then call it with various values of x

for e.g. see this page

http://www.ucalc.com/mathparser/sample6.html

It is very fast. I have used it in VB when there is lot of number
crunching to be done.
Is there a Python equivalent.

I looked at numPy and SciPy sites (just skimmed through) did'nt seem
to have what I wanted.

Any pointers?


--
DarkCowherd

[Larry Bates]

Re: UCALC equivalent

Python has built in eval function and doesn't require
a library.

Larry Bates

Dark Cowherd wrote:[color=blue]
> http://www.ucalc.com/mathparser/index.html
>
> There is a great library called UCALC which allows you to set up an
> expression and evaluate it
> for e.g. you an define an expression by calling a function in UCALC
> then call it with various values of x
>
> for e.g. see this page
> http://www.ucalc.com/mathparser/sample6.html
>
>
> It is very fast. I have used it in VB when there is lot of number
> crunching to be done.
> Is there a Python equivalent.
>
> I looked at numPy and SciPy sites (just skimmed through) did'nt seem
> to have what I wanted.
>
> Any pointers?
>
>[/color]

[Larry Bates]

Re: UCALC equivalent

Python has built in eval function and doesn't require
a library.

Larry Bates

Dark Cowherd wrote:[color=blue]
> http://www.ucalc.com/mathparser/index.html
>
> There is a great library called UCALC which allows you to set up an
> expression and evaluate it
> for e.g. you an define an expression by calling a function in UCALC
> then call it with various values of x
>
> for e.g. see this page
> http://www.ucalc.com/mathparser/sample6.html
>
>
> It is very fast. I have used it in VB when there is lot of number
> crunching to be done.
> Is there a Python equivalent.
>
> I looked at numPy and SciPy sites (just skimmed through) did'nt seem
> to have what I wanted.
>
> Any pointers?
>
>[/color]

[max]

Re: UCALC equivalent

Larry Bates <lbates@syscono nline.com> wrote in
news:42FCDCA7.7 030107@sysconon line.com:
[color=blue]
> Python has built in eval function and doesn't require
> a library.
>
> Larry Bates
>[/color]

Are you kidding? Read the original post a little more closely. The
o.p. is looking for a library that evaluates mathematical expressions
and is callable from python code.

max

[Scott David Daniels]

Re: UCALC equivalent

max wrote:[color=blue]
> Larry Bates <lbates@syscono nline.com> wrote in
> news:42FCDCA7.7 030107@sysconon line.com:[color=green]
>>Python has built in eval function and doesn't require a library.[/color]
>
> Are you kidding? Read the original post a little more closely. The
> o.p. is looking for a library that evaluates mathematical expressions
> and is callable from python code.[/color]

He is absolutely correct.
From the web page referenced:

ucDefineFunctio n("area(length, width) = length*width");
ucDefineFunctio n("frac(x)=abs( abs(x)-int(abs(x)))");
ucDefineFunctio n("test() = 5");
ucDefineFunctio n("abc(x, y=10) = x + y");
ucDefineFunctio n("shl[x, y] = x * 2^y");

cout.precision( 16);
cout << ucEval("frac(15 0/17) * area(20,30)") << endl;
cout << ucEval("abc(5)-abc(3,4)*(#b011 01 shl 1)")
<< endl;


The python equivalent:

exec "def area(length,wid th): return length*width"
exec "def frac(x): return abs(abs(x) - int(abs(x)))"
exec "def test(): return 5"
exec "def abc(x, y=10): return x + y"
exec "def shl(x, y): return x * 2^y"

print eval("frac(150/17) * area(20,30)")
print eval("abc(5) - abc(3,4) * shl(0x0E, 1)")

--Scott David Daniels
Scott.Daniels@A cm.Org

[Max Erickson]

Re: UCALC equivalent

Scott David Daniels <Scott.Daniels@ Acm.Org> wrote in
news:42fcea4a$1 @nntp0.pdx.net:
[color=blue]
> max wrote:[color=green]
>> Larry Bates <lbates@syscono nline.com> wrote in
>> news:42FCDCA7.7 030107@sysconon line.com:[color=darkred]
>>>Python has built in eval function and doesn't require a library.[/color]
>>
>> Are you kidding? Read the original post a little more closely.
>> The o.p. is looking for a library that evaluates mathematical
>> expressions and is callable from python code.[/color]
>
> He is absolutely correct.
> From the web page referenced:
>
> ucDefineFunctio n("area(length, width) = length*width");
> ucDefineFunctio n("frac(x)=abs( abs(x)-int(abs(x)))");
> ucDefineFunctio n("test() = 5");
> ucDefineFunctio n("abc(x, y=10) = x + y");
> ucDefineFunctio n("shl[x, y] = x * 2^y");
>
> cout.precision( 16);
> cout << ucEval("frac(15 0/17) * area(20,30)") << endl;
> cout << ucEval("abc(5)-abc(3,4)*(#b011 01 shl 1)")
> << endl;
>
>
> The python equivalent:
>
> exec "def area(length,wid th): return length*width"
> exec "def frac(x): return abs(abs(x) - int(abs(x)))"
> exec "def test(): return 5"
> exec "def abc(x, y=10): return x + y"
> exec "def shl(x, y): return x * 2^y"
>
> print eval("frac(150/17) * area(20,30)")
> print eval("abc(5) - abc(3,4) * shl(0x0E, 1)")
>
> --Scott David Daniels
> Scott.Daniels@A cm.Org
>[/color]

Ouch, I sure was wrong. You did such a good job making me look
foolish that it was mentioned in Python-URL!. At least Larry Bates
had the grace not to call me an idiot.

max

[Scott David Daniels]

Re: UCALC equivalent

Max Erickson wrote:[color=blue]
> Scott David Daniels <Scott.Daniels@ Acm.Org> wrote in
> news:42fcea4a$1 @nntp0.pdx.net:
>
>[color=green]
>>max wrote:
>> From the web page referenced:
>> ...
>> cout << ucEval("abc(5)-abc(3,4)*(#b011 01 shl 1)")
>> << endl;
>>The python equivalent:
>> ...
>> print eval("abc(5) - abc(3,4) * shl(0x0E, 1)")[/color]
>
> Ouch, I sure was wrong. You did such a good job making me look
> foolish that it was mentioned in Python-URL!.[/color]
Sorry, I wasn't trying to make you look foolish. I was trying to
nip a misconception in the bud.

I also forgot how to convert binary to an integer (the #b01101 above)
when I was writing it, so that last line should read:
print eval("abc(5) - abc(3,4) * shl(int('01101' , 2), 1)")


--Scott David Daniels
Scott.Daniels@A cm.Org

[Cameron Laird]

Re: UCALC equivalent

In article <Xns96B0C211F72 E8maxericksongm ailcom@216.168. 3.44>,
Max Erickson <maxerickson@gm ail.com> wrote:

[Dark Cowherd]

Re: UCALC equivalent

thx,

Well moving to Python from another language needs lots of chanegs
inside your head.

--
DarkCowherd

[William Park]

Re: UCALC equivalent

Dark Cowherd <darkcowherd@gm ail.com> wrote:[color=blue]
> http://www.ucalc.com/mathparser/index.html
>
> There is a great library called UCALC which allows you to set up an
> expression and evaluate it
> for e.g. you an define an expression by calling a function in UCALC
> then call it with various values of x
>
> for e.g. see this page
> http://www.ucalc.com/mathparser/sample6.html
>
> It is very fast. I have used it in VB when there is lot of number
> crunching to be done.
> Is there a Python equivalent.
>
> I looked at numPy and SciPy sites (just skimmed through) did'nt seem
> to have what I wanted.
>
> Any pointers?[/color]

Python has 'eval' and 'exec', so you can process at run-time anything
that you can type into script file. However, it will be a bit more
verbose than UCALC, because Python is more general.

If you're looking for scientific calculator, which can be embedded or
scripted, then perhaps you should take a look at

http://home.eol.ca/~parkw/index.html#rpn

It is RPN calculator with full support for <math.h> functions and some
features found in typical programmable scientific calculators.

Eg.
3+4/5-8 --> rpn 4 5 / 3 + 8 - = --> -4.2

x^2+5x-10
--> rpn 'f(x)= dup 5 + x 10 -'
rpn 1 'f(x)' = --> -4
rpn 5 'f(x)' = --> 40
or it can be scripted directly using shell function, like
--> func () {
rpn $1 dup 5 + x 10 - =
}
func 1
func 5

Sum(x^2+5, 1, 10). I assume this is sum of x^2+5, for x=1,2,...,10
--> rpn clear
for i in {1..10}; do
rpn $i x^2 5 + +
done
rpn = --> 435

--
William Park <opengeometry@y ahoo.ca>, Toronto, Canada
ThinFlash: Linux thin-client on USB key (flash) drive

http://home.eol.ca/~parkw/thinflash.html

BashDiff: Super Bash shell

http://freshmeat.net/projects/bashdiff/

[John Machin]

Re: UCALC equivalent

Scott David Daniels wrote:[color=blue]
> max wrote:
>[color=green]
>> Larry Bates <lbates@syscono nline.com> wrote in
>> news:42FCDCA7.7 030107@sysconon line.com:
>>[color=darkred]
>>> Python has built in eval function and doesn't require a library.[/color]
>>
>>
>> Are you kidding? Read the original post a little more closely. The
>> o.p. is looking for a library that evaluates mathematical expressions
>> and is callable from python code.[/color]
>
>
> He is absolutely correct.
> From the web page referenced:
>
> ucDefineFunctio n("area(length, width) = length*width");
> ucDefineFunctio n("frac(x)=abs( abs(x)-int(abs(x)))");
> ucDefineFunctio n("test() = 5");
> ucDefineFunctio n("abc(x, y=10) = x + y");
> ucDefineFunctio n("shl[x, y] = x * 2^y");
>
> cout.precision( 16);
> cout << ucEval("frac(15 0/17) * area(20,30)") << endl;
> cout << ucEval("abc(5)-abc(3,4)*(#b011 01 shl 1)")
> << endl;
>
>
> The python equivalent:
>
> exec "def area(length,wid th): return length*width"
> exec "def frac(x): return abs(abs(x) - int(abs(x)))"
> exec "def test(): return 5"
> exec "def abc(x, y=10): return x + y"
> exec "def shl(x, y): return x * 2^y"[/color]

Perhaps this should be:
exec "def shl(x, y): return x * 2 ** y"
or
exec "def shl(x, y): return x << y"
[color=blue]
>
> print eval("frac(150/17) * area(20,30)")
> print eval("abc(5) - abc(3,4) * shl(0x0E, 1)")
>
> --Scott David Daniels
> Scott.Daniels@A cm.Org[/color]

[Scott David Daniels]

Re: UCALC equivalent

John Machin wrote:[color=blue]
> Scott David Daniels wrote:[color=green]
>> max wrote:[color=darkred]
>>> Larry Bates <lbates@syscono nline.com> wrote in[/color]
>> The python equivalent:
>> ...
>> exec "def shl(x, y): return x * 2^y"[/color]
>
> Perhaps this should be:
> exec "def shl(x, y): return x * 2 ** y"
> or
> exec "def shl(x, y): return x << y"[/color]
Exactly.
Demonstrating the problems of not actually running a test case
with known results.

--Scott David Daniels
Scott.Daniels@A cm.Org