assume' not working with find(x,y,z) ...?

[SylvainFlamant]

I was solving a simple geometry problem for my son... I reduced the problem to a set of 3 equations with 3 positive unknown variables ( 3 distances so they need to be positive) .

Using the symbolic engine, Mathcad 14.0 has no problem finding a set of 4 solutions... including the one I was looking for , with positive numbers.

So I wanted to add the constraint that the solution had to be real and positive using the modifier "assume, ALL = RealRange(0,100))" in conjunction with the Given and Find(a,b.c) block.

I know that the syntax "assume, ALL = RealRange(0,100))" works when trying to simplify one single equation with multiple variables as shown in the tutorials, but it seems to be ignored in the context of a Given and Find block...

Maybe somebody can tell me what I am doing wrong in the attached file.

Thanks

sylvain flamant

[ptc-1368288]

On 3/12/2009 3:41:03 AM, adiaz wrote:
>This is my approach selecting
>solutions.
>
>Alvaro.
______________________________

I had it working before bed time but was wondering if there is a way to get it w/o prior knowledge of the form of the solution so to avoid the reverse engineering. Reverse engineering seems a difficult and curious step as commented in previous posts. But reverse engineering is a similar step in maths than iterating Q:= f(Q) and very common in maths applied to engineering work and non linear programming. So common that all solvers do behind the scene and forgotten.

I'm trying to make 2 points in there:

1. Get the general knowledge of what Mathcad does on its own.
2. Expose the power of Mathcad via the scalar assignment.




I would like to attach the work sheet but refuse because for those in the learning process *.gif is the ticket for a free lunch.

Would it be really useful to have a special instruction for Mathcad to report the matrix of solutions first. Welcome for more suggestions, my art is done on that and can't sacrifice the lamb for the rabbit.

How do you like it Sylvain ? Jean

[ptc-1368288]

Erratum:

"my art" = my part

[ptc-1368288]

"reverse engineer" is a classical expression even in the "Agreement". Some might prefer to read "post process what must be first pre-processed". In other words: slice the carrot cross wise after slicing length wise.

jmG

[SylvainFlamant]

This is good.

Thanks

sylvain flamant

[SylvainFlamant]

Thank you Alvaro,

This is a valuable input...
I will remember it.

sylvain flamant

[PhilipLeitch]

He he he...

I think on many arguments/debates he and I will have to just maintain our seperate oponions (i.e. statistics). Sometimes I don't understand because there is pure maths and statements but I don't know, see or understand the reasoning behind it.

But my point was that I don't think Jean was intending to be rude/insulting by his language. Calling someone "ignorant" probably has cultural implications in English that that don't in French (I'm assuming).

Saying someone is "ignorant" does litterally mean lacking in knowledge/learning about a particular thing. I'm ignorant to the plight of Russian mice in winter. But in English it has implications lack of sophistication, an overall lack of Education. Calling someone ignorant is almost insinuates a lack of mental capacity (e.g. similar to calling someone dumb or an imbecile). It would have been "nicer" to say, "Like most users you aren't aware of the complex rules underlying Mathcad's symbolics." - or something like that.

I still find many of his posts (especially worksheets) interesting and informative.

Philip
___________________
Nobody can hear you scream in Euclidean space.

[alnstevens]

Getting back to the original query (sorry to spoil the fun!), I've looked at it again. M14 seems to require an auxiliary equation that contains the desired condition in order to get "assume" to work.

I've saved the attached in M11 format, but note that M11 doesn't like it - it only works properly in M14.

stv

[PhilipLeitch]

Hey - that is interesting.

You are right too - putting the SAME log into the assume (without the step you put in) doesn't work.

Well done.

Philip
___________________
Nobody can hear you scream in Euclidean space.

[ptc-1368288]

It does not work any better, Mathcad ! WANTS !
to tell you to make a choice and needs the scalar instruction like posted after your post in this thread.




jmG

[alnstevens]

On 3/12/2009 11:33:51 AM, jmG wrote:
>It does not work any better,
>jmG

Yes, it does work better - but only in M14. As I noted in my post, it doesn't work at all in M11.

Moreover, even in M14 the auxiliary equation must be written exactly as I wrote it. If you remove the external brackets it fails and if you replace the logical ANDs by multiplications (as in jmg's picture) it fails! This ultra-sensitivity to the way expressions must be written strongly suggests a fix is required.

stv

[ptc-1368288]

>This ultra-sensitivity to the way expressions must be written strongly suggests a fix is required <.
_____________________

That ultra sensitivity as you say is simply that the Bolean = is just a bolean = , like the "if" and "if". For greater flexibility you must start considering the "Mathcad native scalar structure" as the two suggestions about a vector and complete Bolean algebra. Did you try my version or does Alvaro version works in your 14 ? If it works, that's the way to conserve, no matter how long the band-aid you put or suggest for 14, too much band-aid will choke that version as will choke the patient.

I made public my opinion about 14, even if I don't have, I have seen enough of those things that don't work in that version but work in 11. Mathcad 14 is a maligned version, maligned by design or intention or juvenile dream = maligned. Mathcad will never be the "Mathcad it was once upon a time version 11.2a".

My point is: install either of the suggested working replies. If they work fine in 14 = glad, if not ? abandon, persist, persecute PTC ...But there is no ultra sensitivity, just incorrect approach. If it works for you like for Alvaro and jmG, no need for a fix.

jmG

[SylvainFlamant]

This is quite interesting, that this is working, while some other formulations are not... That is just pointing to the fact that PTC will eventually have to do some clean-up...

sylvain flamant

[ptc-1368288]

You are damned right Philip,

An ignorant person is just a person that ignores the matter by lack of education or knowledge or simply lack of having be cared of the matter. "ignorant" does not qualify the person, only disqualify. It does have a more powerful meaning than the Vth amendment !

It is a blessing word ... an inviting word.

The equality to "ignorant" is

"La connaissance est un bien qui se partage et n'appauvrit pas celui qui la dispense".

� Knowledge is a "gift", that the man of such goodness to share won't get poorer.

jmG

[PhilipLeitch]

Yes - but words change over time and hence the difference between meaning of very similar words in close languages.
"Ignore" implies intention not to know. I'm ignoring the mess on my desk because I have more important things to do. In the true sense of the word I'm not ignorant of the mess - I am totally aware of it.

Naughty is case in point. It used to be one of the worst things you could call a person and implied they had "Naught" of the attributes that made a man (without virtue - without any worth - without any good qualities). Now it just means that you haven't done the right thing.


Philip
___________________
Nobody can hear you scream in Euclidean space.

[ptc-1368288]

"Ignore" implies intention not to know. [Philip]
__________________________

No Philip,

Ignore come from latin "ignorare = ne pas conna�tre, ne pas savoir ...

no cognition, no knowledge, know nothing about.

"ignore" does not imply any intention.
he wanted to ignore the facts is as ridiculous as saying he does no want to admit the moon is square.

jmG

[PhilipLeitch]

On 3/12/2009 7:36:18 PM, jmG wrote:

>Ignore come from latin
>"ignorare = ne pas conna�tre,
>ne pas savoir ...
>
>no cognition, no knowledge,
>know nothing about.
>
>"ignore" does not imply any
>intention.
>he wanted to ignore the facts
>is as ridiculous as saying he
>does no want to admit the moon
>is square.
>
>jmG

That's my point - in English it DOES imply intention. Sure it COMES from Latin, but many words have changed from their original meaning, somtimes to mean the complete opposite of their original meaning.


From Dictionary.com for "Ignore":
"to refrain from noticing or recognizing: to ignore insulting remarks."

Refrain is an act of intention.


In a google window type this:
Define:Ignore

Look at the results:

- refuse to acknowledge; "She cut him dead at the meeting"
- dismiss: bar from attention or consideration; "She dismissed his advances"
- fail to notice
- neglect: give little or no attention to; "Disregard the errors"

Or - my personal favourite:
- to refuse to recognize or notice something


Can you see now how your "factually correct" sentence appeared as an attack? Dismissive, neglect, refusal to acknowledge... clearnly not your intention and clearly not very nice. "Ignore" still carries the "fail to notice" meaning, but that is far down the list compared to common usage.

This was my point, that because I know your writing style I knew you weren't being insulting, but to an English speaking person it was.

I'm not asking you to change your style - just trying to make other people aware.

Philip
___________________
Nobody can hear you scream in Euclidean space.

[ptc-1368288]

You are quite right :
He ignored my advice, consequently cut his finger.

But an ignorant person is a person not having the knowledge of the matter, the cognition.

[PhilipLeitch]

And also means ill mannered, crude, lacking sophistication, foolish; silly, and ignoramous.

Hence the sentence was taken as an insult.

Philip
___________________
Nobody can hear you scream in Euclidean space.

[ptc-1368288]

I have never been insulted by clients telling in meeting "Jean is ignorant of that", for sure that was always agreed that consultants would be kept out of some part of the process. That's probably why I have been the only single person consultant for an Atomic Energy leader + + + But on the day they had a failure that did cost 6 months of production they were glad they had in hand a "Reverse Engineer". I was glad too having a "bit man" working close to me, and after: we were mutually less ignorant.

jmG

[PhilipLeitch]

I can't speak for the world, but if an English speaking person called me ignorant, then I would absolutely assume it as an insult. They would say "Philip doesn't know anything about XYZ" if not instulting me, and "Philip is ignorant about XYZ" if they were. The second is most definately an insult.

You might not have taken it that way, but if they said it that way, they meant it as an insult...

If they were British/Australian anyway... I can't speak for the Americas.


Philip
___________________
Nobody can hear you scream in Euclidean space.

[ptc-1368288]

>I can't speak for the world <<br> ____________________________

Then ! DON'T ! specially referring to persons you know nothing about.
Just be a collab as you wish or not.
At some point, your obsession becomes insulting.
I have other matters to deal with.

jmG

[ptc-1368288]

What I have found most insulting in this collab is the comparative number of typos and gross typos from english speaking vs non english speaking as well as their slang, and not the least, their sarcastic and insidious remarks.

That was an interesting octAgon issue yet to be seen in picture for the majority of non 13, 14 users. Not that important as most previous versions users have found their way out.

Sometimes I post the abstract of some work sheet considered "tool", so those interested can download or ignore. There is one coming.

jmG

[PhilipLeitch]

Well - I for one apologise for any office I have caused - none intended. Topic dropped.

RE typos, out right spelling mistakes and slang, that's part of my language for better or worse. I make no appologies and will not change.

RE sarcastic and insidious remarks - agreed. They seem to come out of misunderstandings and frustration due to communication break downs, either litterally language barriers, or lack of understanding/respect of each-other's posts and ideas/arguments. That's what prompted me to say something in the first place - the negative comments seem to be increasing and I don't think they are called for.

Philip
___________________
Nobody can hear you scream in Euclidean space.

[TomGutman]

>>I still find many of his posts (especially worksheets) interesting and informative.<<

Yes. Although in most cases you are better off finding the original. Case in point in this thread (message 47). Here he has indeed posted a picture of an interesting technique. But it is nothing more than Alvaro's sheet (message 39), with a somewhat different layout and some change in names. He has not even fixed Alvaro's fairly obvious mistake. I do not believe that Jean's post here adds anything to the discussion, other than being another post with Jean's name on it.
__________________
� � � � Tom Gutman

[ptc-1368288]

On 3/12/2009 12:22:34 PM, Tom_Gutman wrote:
>>>I still find many of his posts (especially worksheets) interesting and informative.<<
>
>Yes. Although in most cases
>you are better off finding the
>original. Case in point in
>this thread (message 47).
>Here he has indeed posted a
>picture of an interesting
>technique. But it is nothing
>more than Alvaro's sheet
>(message 39), with a somewhat
>different layout and some
>change in names. He has not
>even fixed Alvaro's fairly
>obvious mistake. I do not
>believe that Jean's post here
>adds anything to the
>discussion, other than being
>another post with Jean's name
>on it.
>__________________
>� � � � Tom Gutman
___________________

Curiously enough I'm the only collab who rotated the 3D externally via the CreateMesh parametric vector scalar as I have explained in my reply, and how many work sheets I have posted filling regions, with Bolean algebra just a combination of the two's. That I needed some bed time is no one business. Like you say it can't be much different except for the scalar explanation and that's true I couldn't make the symbolic expansion not display, but I did well for the TCF (Thiele Continued Fraction]

Truly enough, the symbolic is more than a gadget and should be kept as a separate entity or review the interface ... easy to say in words but a menu does not fill the plate.

Interesting by how much the next polygon will enrich the readers.

jmG

[SylvainFlamant]

"ignorant" in french has the same "bad" connotation as in english...


sylvain flamant

[ptc-1368288]

On 3/12/2009 9:39:46 PM, sflamant wrote:
>"ignorant" in french has the
>same "bad" connotation as in
>english...
>
>
>sylvain flamant
____________________________

Connotation is one thing, the meaning is another and in maths we are rather strict to the meaning in all the ways, even words that describe the level of knowledge.

See the definition of ignorant in Larousse (vg).

jmG

[PhilipLeitch]

Language can never be "set in stone". If you are using that specific definition then you are the only one on this site doing so. That may apply to accademic literature, but this is a forum.

Even when definitavely stated in a piece of literature specific to a subject, common use will change and adapt over time.

That's the beauty and curse of a common spoken language.

Sanskrit would be the only language I'm aware of to have never adapted (well... beyond addition of words) because it has never been a common language, but entirely accademic from construction. I would include Esparanto... but I don't think that is a "live" language whereas Sanskrit has many speakers and even does web forums and TV broadcasts.

Philip
___________________
Nobody can hear you scream in Euclidean space.

[SylvainFlamant]

Jean, well I don't fully agree:

If I look at the following french site that goes deeply in researching the meaning of french words...

http://atilf.atilf.fr/dendien/scripts/tlfiv4/showps.exe?p=combi.htm;java=no;


no matter how I look at it , half the examples given for "ignorant" are pejorative... The meaning of a word, is not only how it is defined in a dictionary, but also how it is being used by most people... ( that is how words evolve. ) The fact that that in french there are legitimate uses of the word "ignorant" in its original neutral meaning doesn't remove the fact that it is often used in a pejorative way . "Tu es un ignorant..." ( You are an ignorant ...) for example, is never neutral...



Besides, one of the paragraph specifically speaks of the possible strongly negative connotation of the word :
"...Avec une valeur d�pr�c. et/ou pol�mique fortement marqu�e dans le contexte ".

and then, one has to just look at some of the examples and the type of words associated with the word "ignorant":

" On voit un tas de pleutres, d'ignorants et de pas grand'chose ..."

"Ignorant et born�, corrompu..."

"Avec tout cela, ignorant comme un pot et provincial jusque dans les moelles ..."

"Ignorant comme un �ne...".

I translate the last two:
" With all this, ignorant like a pot and "redneck" to the bone ..."

"Ignorant like an ass ..."


It is interesting to go back to the dictionaries of "L'academie Francaise" through the centuries ( which is the accepted "authority" in matters of french language )... Through the 8 first versions of the dictionnary ( available on the internet @ http://colet.uchicago.edu/cgi-bin/dico1look.pl?strippedhw=ignorant&dicoid=ACAD1694 ) We can see that one important meaning of the word is not only that a person doesn't know , but that the person Should know... There is a negative judgement there... and the last version of the dictionary (the 9th one) mentions a couple of expressions : "Ignorant like an ass " (or a pot) being one of them.



sylvain flamant

[PhilipLeitch]

I love the Black Adder episode where he is denograting the first English Dictionary by saying something along the lines of: "It's the most useful book since 'How to Speak French' was traslated into French."

he he he.

Anyway - I'm going to stop posting in these threads because we are way off topic... mostly due to me.

Cheers,
Philip
___________________
Nobody can hear you scream in Euclidean space.