5525 Views 33 Replies Latest reply: Oct 29, 2010 6:16 PM by A.Non
335 posts since
Jan 22, 2007
Currently Being Moderated

## Finding and Marking.

Hi,
I have a similar question and need help. ( WORKING ON  .MCD12 )

Finding the 6-decimal numbers and marking. (like as above)
Regards, -LL-

Attachments:
• 4,869 posts since
Jun 1, 2007
Currently Being Moderated
Oct 27, 2010 6:20 PM (in response to lvl107)
Re: Finding and Marking.

The attached gives one possibility.   Create a vector whose elements are 1 if the corresponding elements in the target vector match a given criteria (eg, have more than 3 decimal places).   Then use that list to mark up the corresponding elements in the target vector.

Stuart

I don't know if it will work in M12, but it works in M11 and M15.

Attachments:
• 4,522 posts since
Dec 3, 2008
Currently Being Moderated
Oct 28, 2010 12:00 AM (in response to StuartBruff)
Re: Finding and Marking.

Nice explanation Stuart.

Lovely use of the mod function.

Mike

• 4,869 posts since
Jun 1, 2007
Currently Being Moderated
Oct 28, 2010 12:50 AM (in response to MikeArmstrong)
Re: Finding and Marking.

Thanks, Mike.

As I hint at in the text, it needs a bit of care in the numerical round-off region, but the numbers given are relatively easy to deal with.  Perhaps somebody might like to suggest a better selection function?

Stuart

• 10,404 posts since
May 11, 2010
Currently Being Moderated
Oct 28, 2010 6:32 AM (in response to StuartBruff)
Re: Finding and Marking.

This marks a specific number of decimal places. It's a bit of a mixed up approach, but I  think it should be reliable. It would be less mixed up if I also used string functions to find the number of digits before the decimal point, but the ceil(log) approach was the first thing I thought of and I'm too lazy to change it

Attachments:
• 4,522 posts since
Dec 3, 2008
Currently Being Moderated
Oct 28, 2010 6:24 AM (in response to A.Non)
Re: Finding and Marking.

Nicely done.

Have a look below, should your function be:-

Mike

• 4,869 posts since
Jun 1, 2007
Currently Being Moderated
Oct 28, 2010 7:13 AM (in response to A.Non)
Re: Finding and Marking.

Richard Jackson wrote:

This marks a specific number of decimal places. It's a bit of a mixed up approach, but I  think it should be reliable. It would be less mixed up if I also used string functions to find the number of digits before the decimal point, but the ceil(log) approach was the first thing I thought of and I'm too lazy to change it

Do you mean something like the attached, using search?

Stuart

Attachments:
• 4,522 posts since
Dec 3, 2008
Currently Being Moderated
Oct 28, 2010 7:50 AM (in response to StuartBruff)
Re: Finding and Marking.

Very nice.

Can we stop adding additional functions / methods - I'm struggling to document all the examples

Mike

• 10,404 posts since
May 11, 2010
Currently Being Moderated
Oct 28, 2010 8:26 AM (in response to StuartBruff)
Re: Finding and Marking.

Something like that, yes.

Or perhaps

• 4,869 posts since
Jun 1, 2007
Currently Being Moderated
Oct 28, 2010 8:49 AM (in response to A.Non)
Re: Finding and Marking.

Richard Jackson wrote:

Something like that, yes.

Or perhaps

This colonial quest for efficiency is rubbing off on you, isn't it?

• 10,404 posts since
May 11, 2010
Currently Being Moderated
Oct 28, 2010 10:25 AM (in response to StuartBruff)
Re: Finding and Marking.

This colonial quest for efficiency is rubbing off on you, isn't it?

Too right! One must be careful not to waste flops. Wasted flops means wasted energy, which leads to global warming and the end of the world as we know it!

• 4,522 posts since
Dec 3, 2008
Currently Being Moderated
Oct 28, 2010 11:36 AM (in response to A.Non)
Re: Finding and Marking.

While I am contemplating the prospect of the end of the world like we know!!! - have we reached the maximum of Mathcad's capability on this subject????

Am I right to assume that both you and Stuart are still learning of each other?

Mike

• 10,404 posts since
May 11, 2010
Currently Being Moderated
Oct 29, 2010 6:16 PM (in response to MikeArmstrong)
Re: Finding and Marking.

The majority of what I know about Mathcad I have learned from others that posted to the Collaboratory. Stuart is one of many. I am still leanring. That's a good thing, because if one is no longer learning then one are either senile or dead.

• 4,869 posts since
Jun 1, 2007
Currently Being Moderated
Oct 29, 2010 2:06 AM (in response to A.Non)
Re: Finding and Marking.

Richard Jackson wrote:

This colonial quest for efficiency is rubbing off on you, isn't it?

Too right! One must be careful not to waste flops. Wasted flops means wasted energy, which leads to global warming and the end of the world as we know it!

Is this what happened to Jean?  Was he neglecting to balance his flips with some flops and getting overheated?  It certainly lead to the end of the Mathcad World as we knew it.    I suppose the question is are we mammals or dinOsaurs looking at that old meteor headed towards Chicxulub?

Stuart

Err, Jean? Wakey, Wakey..  RUUUUNNNN!

• 10,404 posts since
May 11, 2010
Currently Being Moderated
Oct 29, 2010 6:15 AM (in response to StuartBruff)
Re: Finding and Marking.

Jean, burying your head in the sand won't help You said the calculations showed it would miss us! I told you we should have used units!

• 4,869 posts since
Jun 1, 2007
Currently Being Moderated
Oct 29, 2010 6:29 AM (in response to A.Non)
Re: Finding and Marking.

Richard Jackson wrote:

Jean, burying your head in the sand won't help You said the calculations showed it would miss us! I told you we should have used units!

ROFLMAO!!!!

I wonder if Mr Lamb is still around? - I think he'd appreciate the astronomical and unit references

• 4,522 posts since
Dec 3, 2008
Currently Being Moderated
Oct 29, 2010 10:53 AM (in response to A.Non)
Re: Finding and Marking.
Jean, burying your head in the sand won't help You said the calculations showed it would miss us! I told you we should have used units!

Now now fellers.

Mike

• 4,869 posts since
Jun 1, 2007
Currently Being Moderated
Oct 29, 2010 12:27 AM (in response to lvl107)
Re: Finding and Marking.

Loi Le wrote:

Richard, it seems that I understand your idea on above, so I would update my question as similar one.

( Finding the 6-decimal numbers, and Replace them by their Row-index and Marking )
Regard, -LL-

Couple of ways to get started.

1.   If you use a version of a function that iterates through the vector and uses an expression involving the index, then simply replace the 'value' with the index.

2.   Use a simple 'filter' functions that iterates through the 'normal' result and replaces each nested array (marked element) with its index.

Stuart

Attachments:
• 4,522 posts since
Dec 3, 2008
Currently Being Moderated
Oct 29, 2010 12:59 AM (in response to StuartBruff)
Re: Finding and Marking.

Slight alternative attached.

I have combined into one program so the function is only dependant on one pre-defined function.

Mike

Attachments:
• 4,869 posts since
Jun 1, 2007
Currently Being Moderated
Oct 29, 2010 2:35 AM (in response to MikeArmstrong)
Re: Finding and Marking.

Mike Armstrong wrote:

Slight alternative attached.

I have combined into one program so the function is only dependant on one pre-defined function.

Mike

Oh.  I see.  If somebody else suggests a new method then you can't keep up, but if Micheal suggests one ...   (exit.  stage right. flounce.)

I like the use of match, but it is possible to make slightly more efficient use of the results.   OOIC, why did you add one to the index?

Stuart

Attachments:
• 4,522 posts since
Dec 3, 2008
Currently Being Moderated
Oct 29, 2010 2:42 AM (in response to StuartBruff)
Re: Finding and Marking.

Ok. I give up you win..... I like this game though.

I added 1 to the results just to match the original request - Just having one of those moments, sorry!!!!!!

Mike

• 4,869 posts since
Jun 1, 2007
Currently Being Moderated
Oct 29, 2010 3:12 AM (in response to MikeArmstrong)
Re: Finding and Marking.

Mike Armstrong wrote:

Ok. I give up you win..... I like this game though.

WIWAC, I only got angry with people once; I was lead on a 4 hr exercise (tracking some evaders).  10 minutes before endex, I reckoned the 'enemy' had passed through the area I was staking out and got the team to load up on the 4-tonner to head for the next point I thought the enemy would head for.   The team got on the lorry, then just sat down looking inwards.   Sudden transformation on my part from Mister Quiet to Raging Fury - get off your backsides and get looking .   Got the enemy 2 minutes later!

So the moral of the story is "Don't give up.  It ain't over 'till the fat lady sings.".   It is a good game, and I draw inspiration from both your's and Richard's solutions.

So many ways to skin them, so few cats

or is that, so many ways to kill them, so few lawyers?

(WIWAC - When I Was At Cranwell)

I added 1 to the results just to match the original request - Just having one of those moments, sorry!!!!!!

Mike

Ah, OK.  I assumed it was because they were using ORIGIN=1.   The match solution should work, provided the function is defined where ORIGIN is 1.

Stuart

• 4,522 posts since
Dec 3, 2008
Currently Being Moderated
Oct 29, 2010 10:51 AM (in response to StuartBruff)
Re: Finding and Marking.
So many ways to skin them, so few cats

or is that, so many ways to kill them, so few lawyers?

Ah, OK.  I assumed it was because they were using ORIGIN=1.   The match solution should work, provided the function is defined where ORIGIN is 1.

ORIGIN = 1 ----- Of course.

Another moment where my brain cell got a little overloaded.

Mike

• 10,404 posts since
May 11, 2010
Currently Being Moderated
Oct 29, 2010 6:31 AM (in response to lvl107)
Re: Finding and Marking.

You can't do that, because you do not have enough digits of precision. You have only about 16 digits, so 0.1+1*10^-20 is just rounded off to 0.1 when it is stored.

• 4,869 posts since
Jun 1, 2007
Currently Being Moderated
Oct 29, 2010 6:54 AM (in response to lvl107)
Re: Finding and Marking.

Loi Le wrote:

Stuart,

( Finding the 20-decimal numbers match ( that means the first match, the second match and so on...) (only assume), and Replace them by their Row-index and Marking ) and see the attached.

Regards, Loi.

As Richard says, the numeric processor won't handle that many digits due to the (IEEE standard) floating-point format that Mathcad uses to store numbers.   OTOH, you could use the symbolic processor ...

Stuart

Attachments:
• 4,522 posts since
Dec 3, 2008
Currently Being Moderated
Oct 28, 2010 12:11 AM (in response to lvl107)
Re: Finding and Marking.

It might be worth creating a document of all your latest requests. Each request is similar and would make it much easier if augmented into one document with a brief explanation of how each function works.

You can create it or I will for you.

Cheers

Mike

#### More Like This

• Retrieving data ...

#### Legend

• Correct Answers - 3 points