OT: Math Processing Question

Dec 02, 2015 22 Replies

I'm sure there's been no end of jokes about you sending each other French letters.

When my oldest sister was doing final year high school French and Dad travelled to France, he sent her six foolscap pages hand-written in French... we used to refer to when he sent his daughter a French letter. He had an impressive memory.

Clifford Heath

Does there exist a math program that can take as input:



{12.5m*TANH((V(N_1,0)-(((10mA+15mA)/2)*10*ATANH(((10mA-15mA)/2)/((10mA+15mA)/2))))/10/((10mA+15mA)/2))+((10mA-15mA)/2)}



and reduce it, combining terms, eliminating parentheses, etc, where possible, but leaving variables, such as V(N_1,0) ??



I'm looking for ways to simplify (and obfuscate :-) my Spice models. ...Jim Thompson



-- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

formatting link
| 1962 | I love to cook with wine. Sometimes I even put it in the food.


Qalculate can do some of that - it knows about units and can be asked to simplify:

formatting link

Grizzly H.

80% of that equation reduces to a single constant.

+15mA)/2))))/10/((10mA+15mA)/2))+((10mA-15mA)/2)}

If you're into buying stuff, Mathcad with the symbolic toolbox is very nice. Mathcad uses Maple, as does just about any for-pay mathematical program that includes symbolic manipulation.

Maxima is kind of the gold standard for open-source symbolic simplification (I think it's where Maple comes from), but it's text based, doesn't know how to reduce units (unless you do extensive coaching, I suppose), and can hang up on trig problems. Of course, I've also just described Maple...

Whether Maxima or Maple is the underlying engine, you'll often find that the "obvious" simplification you're looking for is just not coming out. In that case, you can often get a long way by making a guess, and then asking

-

VERY OFTEN, when Maxima can't reduce something to my taste, it'll still correctly cough up 0 when I do the above (and when I've gotten my reduction right).

Tim Wescott Wescott Design Services http://www.wescottdesign.com

Hello Jim,

Quite easy with (wx)maxima with ratsimp();

ratsimp(12.5*TANH((V(N_1,0)-(((10+15)/2)*10*ATANH(((10-15)/2)/((10+15)/2))))/10/((10+15)/2))+((10-15)/2));

-->

(25*TANH((V(N_1,0)-125*ATANH(-1/5))/125)-5)/2

I'm too lazy now ... BTW you have been entering the MIT ... whare have you been there ???

Hum ... take it easy Jim i'm kidding you.

Habib.

PS : same way with MathCAD.

Super! I downloaded the Maxima installer and a "book" about an hour ago.

Long, long ago ;-) 1958-1962

...Jim Thompson

| James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.

...and in a galaxy far, far away.

oh i see ! An MIT veteran ! BTW i never understand what is the meaning of "Mens et Manus" 'cause it's a mix with mens (English) and manus (Latin) stand for body or hand.

I come from the one which the moto is "Docet omnes ubique" and i proud of this.

Habib.

Mens et Manus == Mind and Hand

It teaches everyone everywhere

You should be proud...

...Jim Thompson

| James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.

On Wed, 02 Dec 2015 21:35:10 +0100, Habib Bouaziz-Viallet Gave us:

just google it, dummy.

Ah ok mens ! as mens sana in corpore sano. Apologies.

And sure i am ! we need it most of all on these dark days in France, saying "Docete omnes ubique"

And you're a dummy and half. When i was 11 years old i've learn some latin in French school, i forgot the meaning of mens word in Latin.

My English is unfortunately not so fluent i could express my pity on you ... stupid.

H.

Habib, Just ignore DecadentLoser... he's just that, a total loser... and ignorant to boot.

I'm of the (very) old school... I had three years of Latin in High School and one year of French... my wife-to-be and I communicated in French when I was at MIT and she was still in West Virginia... to thwart her mother reading our love letters ;-) ...Jim Thompson

| James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.

:-) very smart indeed writing French with one's love !

Habib.

Our 56th anniversary on March 31. Our teenage marriage wasn't supposed to last (I was 20, she was 18 ;-) ...Jim Thompson

| James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.

FWIW, I'd treat the units as variables (e.g. 125mA -> 125*mA), which ratsimp will cancel or factor out where possible.

Also, if you convert tanh() and atanh() to lower-case, you may be able to get some mileage out of trigsimp/trigexpand/trigreduce.

}snip{

"Zut, alors! Je t'aime, mon amour!"

Now, was that so difficult? ;)

joe

O.T.: All you've got to blame is your government...

jor

On Wed, 02 Dec 2015 22:01:44 +0100, Habib Bouaziz-Viallet Gave us:

I did not say a goddamned thing about what you may or may have not studied. Even IF you had YEARS of Latin study, when you encounter an unknown, you can GOOGLE it and examine the result... DUMMY!

So YOU are the putz who needs pity, asshole.

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required