I just wanted to show how Mark Walked locked and somehow sorted the list so that a thread with activity three days ago would show up between one from 7 months and one from 5 months ago.
Tom MacMillan wrote:
I just wanted to show ............. sorted ... list so that a thread with activity three days ago would show up between one from 7 months and one from 5 months ago.
The display order is affected by each user's preferences. In the normal indented thread order, you will find your new post [almost] immediately after the thread you replied to, unless it had other sub-replies, and immediately following your reply will be a different reply to some part of the thread higher up the hierarchy. Thus it will have two 'old' threads either side of it.
Sometimes it is just what is wanted, and other times it means that all the latest news is scattered about the whole thread. On the old forum I used the simple date order and managed my reading using the "mark as read" but that isn't available any more so I've resigned my self to just reading the last few threads that look interesting and ignoring the rest. Have a check as to what your preferences are set to. You may want to change them.
I don't like the competitions anyway because they always need 'hidden' rules [= things obviously misunderstood (that's an oxymoron;-)] that I don't always 'get'.
No, I'm not talking about the order of the posts in thead but the order of the threads in the "puzzles & games" section. He did this so that it would not show up on the "What is everyone doing?" list on http://communities.ptc.com/community/mathcad?view=overview. See attached.
The moderator closed the thread because it is about a puzzle we posted more than 6 months ago. The purpose of that puzzle was to showcase the Mathcad Virtual Event last fall, and encourage people to pick up clues at the various stages of the event.
We'll be having another Mathcad Virtual Event later this spring, when we'll discuss where we are with Mathcad Prime 2.0 and our ongoing roadmap. Stay tuned.
Exactly, six months without providing an answer to my question about hidden rules. He then changed some property in the thread to hide this.
Is it policy to lock old threads? I understand the purpose of the puzzle and I attended the event. I provided the first correct solution to the problem.
I'm not aware of any hidden rules, nor do I know how the winner was chosen. It may have been randomly among correct answers, like many contests.
The moderator of the communities decides when to lock threads.
From the other thread:
I didn’t know this debate was still alive, so hopefully I will settle the discussion, at least for a few minutes….
Jean Giraud’s answer did not involve any of the specific pieces of information that were disclosed through the presentations.
Beyond that, Tom MacMillan’s trajectory curve omitted the initial (launch) height of the cannonball. So, his trajectory curve was 75m below where it should have been
We clearly stated that the launch height was 75m above the crater floor…. Not that the crater floor was 75m below the launch height.
Therefore, Chris Kaswer’s answer, although received 10 minutes later, was correct because he included the +75m term in his vertical displacement calculation to drive the trajectory curve.
This is not true. They had a diagram showing a two arrowed dimension "H" . During the event they gave the length of "H", no direction. There was no random selection. They gave this as the only reason that the other (later) solution was better. I used the vaue of "H" to provide what was aked for. See the other (locked) thread for other issues. I wonder how long it will take for this thread to be locked or deleted as well?
Ultimately the winner is selected by the judges panel and the decision is final. Mark and others were fair in their response to your question to why your solution was not chosen.
There are plenty more chances to participate in challenges. Plenty more chances to win gift cards and other prizes. You are more than welcome to join us for those future opportunities, but this challenge is closed.
From the first post in the challenge thread:
*The winner will be chosen based on time of response, accuracy of solution, and best use of Mathcad to derive the answer.
Show me where it says that the trajectory will be based of the crater floor!
The contest was very poorly run, that response is ridiculous. I'm guessing that after waiting two weeks to see if more than 2 people participated in your "Challenge" you picked the person who would cost you the least in shipping.
You added a new rule regarding where the height was to be zeroed to back up your decision and stuck to it.
I was never offered a t-shirt and sure don't want one now.
We'll work harder to be more clear in defining the variables and assumptions. Thank you for pointing out this flaw in the contest. The offer for a t-shirt is still valid. I apologize for assuming you no longer wanted one.
All I want is confirmation from my last question from the other thread, that all of the below is trumped by having the "correct" (but yet unstated in the rules) zero point on the trajectory:
"You have nothing to indicate that on your diagram and during the presentation, I believe that it was announced that "h = 75m". Your diagram also shows a two ended arrow which indicates that h is only a scalar, does not have direction and does not indicate the y origin (by pointing away from it).
My solution was in ten minutes before Chris’.
After solving the equation for vertical motion (without setting it equal to some time variable), he copied both solutions. He incorrectly copied one solution and came up with 2.019s, which has now had no reason to be ignored.
He then cut and pasted again (to only three decimal points) one of the two times into a formula for horizontal displacement – not using mathcad’s ability to update if there were any changes before the point and rounding this time value off. He took the unneeded step of calculating and displaying the time until impact.
He then solved the vertical and horizontal components by plotting the two with discrete points at ½ second intervals, only up to slightly more than the time he calculated previously. He then plotted the two vectors (horizontal vs time and vertical vs time) against each other. This seems very sloppy, not robust, and doesn’t use mathcad’s ability to pass along and update information.
As for the horizontal distance, (Chris 2641m, Me 2609m), he used 1.6m/s^2 instead of the more accurate (from NASA) 1.62m/s^2 (see below).
And the ten minutes difference doesn't seem like much, but look at it like this: The information was provided at each of the sessions at 45 minutes past the hour. I submutted my solution at 1:49 pm. The other solution was submitted at 1:59 pm. So mine was in 4 minutes after the last clue was given and the next answer took 14 minutes after the last clue.
You finally offered a t-shirt in a private message saying that you didn't think I was interested because of my comments in the other thread. Those comments were posted on November 22nd. The event was Setemper 8th. Where was the offer in that length of time?
If you read the previous post in this thread, I pointed out the difference as I see them and recieved no response. I stated that the time difference was not the only issue, but also differences in accuracy and the use of mathcad.
I did not recieve an offer for a t-shirt before I posted my comments 10 weeks after the event. I appologize if I appear frustrated, I did not mean to abuse anyone in this community. I am just looking for confirmation that the points I made were considered and that was the reason for the judges decision.
Thank you Dan for providing some insight into the judging process and the weight certain factors have. Unfortunately this has not changed my opinion of how that contest was ran
I will have to think long and hard about investing any more time into any future contests/events here.
Good luck in the future.