3D graph

[Bilisten-disabl]

Hey,


I have made a 3D graph from 3 tables. Is there a way to get any point in the graph mathcad generated? I dont have a function, only the 3 tables.

[ptc-1368288]

Very easy. For any given set of X,Y values in their corresponding planes, there is a single match Z. There is a procedure to convert nested arrays to scatter vectors. Once at that stage, the search is manual as the X,Y planes may not be flat planes, rather dependent planes. The approach may be different if the all thing comes out of implicit f(x,y).

jmG

[ptc-1368288]

On 6/13/2009 6:56:51 PM, Bilisten wrote:
>Hey,
I have made a 3D graph
>from 3 tables. Is there a way
>to get any point in the graph
>mathcad generated? I don't have
>a function, only the 3 tables.
_______________________________

"the graph Mathcad generated"
Then Mathcad has generated nothing if you don't have a function. Within last 2 months or so, same task was done for another collab, but can't retrieve the project.

jmG

[ptc-1368288]

Click on the link below for a 3 tables nest and finely meshed. It is essential you plot finely meshed first. How far can your project go w/o work sheet and no explanations conducting to solution.

http://collab.mathsoft.com/read?124766,20

That's the project that I just said "can't retrieve".

jmG

[Bilisten-disabl]

Thanks for all your help. It works like a charm.

[ptc-1368288]

On 6/14/2009 7:55:00 AM, Bilisten wrote:
>Thanks for all your help. It
>works like a charm.
_____________________________

Your appreciation is gratifying, thanks too.

The other situation will be when the rows/cols have specific values instead of simply indexing like in the previous work sheet. The attached work sheet is a great tool, passed many times in this collab. It will take rectangular or square array of data, spline and enable the export of the splined project in either form: nested from the Mathcad built-in CreateMesh or from the S(X,Y,Z,s0,s1,t0,t1,xmesh,ymesh)in the collapsed area.

Enjoy

jmG

[Bilisten-disabl]

Hey again,

I guess i got a bit ahead of myself. On my first graph it worked, but my second was not that easy for me. I have plotted a hillside on my gps and uploaded the coordinates to mathcad. The data is in 3 different vectors x, y and z.

My initial problem is that I want to calculate the volum of this hillside. And i was thinking that if i meshed it fine enough, i could use the z coordinates to get a good estimate of the volume.

[ptc-1368288]

On 6/15/2009 9:57:15 AM, Bilisten wrote:
>Hey again,
I guess i got a bit
>ahead of myself. On my first
>graph it worked, but my second
>was not that easy for me. I
>have plotted a hillside on my
>gps and uploaded the
>coordinates to mathcad. The
>data is in 3 different vectors
>x, y and z.
My initial
>problem is that I want to
>calculate the volum of this
>hillside. And i was thinking
>that if i meshed it fine
>enough, i could use the z
>coordinates to get a good
>estimate of the volume.
__________________________

You are not helping yourself by not attaching the work sheet. You have missed understanding the Mathcad 3D plot as now you are talking about 3 vectors. Plotting 3 vectors is plotting 3 vectors and that is not the same as plotting 3 SCATTER VECTORS and not the same as plotting 3 nested matrices as you first had in the worksheet. The best is to show what the data from the GPS are, as raw as possible, just after the binary conversion (as it would read in numerical decimal values). So, not knowing what you have in hand, can't tell if an onion or a monkey.
OK, you want to know the volume of the hill, but where is the hill in a work sheet ? I guess the hill is the level matrix, then a row by row sum and total sum times some factor, but again the worksheet will tell.


jmG

[Bilisten-disabl]

btw, thank you so much for trying to help me. I really appreciate it.
I have attached a small part of the hillside, since its a huge data set.

[ptc-1368288]

On 6/15/2009 4:33:09 PM, Bilisten wrote:
>btw, thank you so much for
>trying to help me. I really
>appreciate it.
>I have attached a small part
>of the hillside, since its a
>huge data set.
_____________________________

"Save as" version 11 or as low as 8 for a large audience.
My version is 11, so can't read your *.XMCD.

jmG

[Bilisten-disabl]

ah, i will

[ptc-1368288]

On 6/15/2009 5:00:42 PM, Bilisten wrote:
>ah, i will
______________________

Now you have 3 vectors that are not "Scatter vectors" neither "nested matrix". So, that's the dilemma, you can plot and interpolate up to 99 (you had default 21) and view all the contours. While trying something, my Mathcad 11 crashed. I don't have the equivalent of the Mathcad built-in QuickPlot "Mesh Interpolate". Never seen it before either.

Conclusion:
a project on the design board or in some collab tool box . What I tried in the past failed and didn't pursue because it was not project oriented. The volume of the hill is the sum of the bars, which bar matrix to be made constitutes the project.

jmG

[PhilipOakley]

Part of your difficulty is that the 'help' for the 3d plotting is not very good at getting you started.

The 3d plot component can use one of the less common constructs - the bracketted list - so you can provide the three column vectors inside a bracketted list. (X,Y,Z) Note that you need the brackets and commas, it is not a matrix... nor a nested matrix.

This will allow a scatter plot.

Enjoy

Philip Oakley

[ptc-1368288]

Philip,

You haven't understood the differences in the Mathcad 3 ways plot. (X,Y,Z) are vector , they are not "scatter vectors". That you can mesh the plot up to 99 (X,Y,Z) is one thing but you don't have an export of either X, Y planes neither the level matrix Z. All that is explained in:

http://collab.mathsoft.com/~Mathcad2000/read?125098,20e#125098

And that's what the collab has passed, i.e: useless (X,Y,Z) for the volume of the hill. Useless up to this point that we don't have the conversion to a user meshable hill. This tool is missing, not for the plot for the user processing.

jmG

[RichardJ]

Here's one approach. The fitted surface doesn't pass exactly through your points (it is a fitted surface, not an interpolated one), but given the sparsity of your data the error in the volume of the hill will be high anyway.

Richard

[ptc-1368288]

On 6/15/2009 4:33:09 PM, Bilisten wrote:
>btw, thank you so much for
>trying to help me. I really
>appreciate it.
>I have attached a small part
>of the hillside, since its a
>huge data set.
_____________________________

The "small part" is too small to make sense. Whatever, I did bite on the smell of the T bone ... good dog ! Small adaptations would automate the project from top to bottom. An interesting project but that eventually you might not want to, otherwise you would have passed much better information and a description, even some procedure in use, that could be modelized in Mathcad.

I have done my best for your project,
(if you ever visit your own thread !!!)

jmG

[ptc-1368288]

... in this work sheet [same but not same], I have added Richard's suggestion for loess. It does not extrapolate on Mathcad 11.2a, does it on 14 ? Whatever, the Createmesh from loess will plot same as Createmesh from the lspline diagonal interpolant, i.e: plot garbage ... why ? because the u, v are not linear, rather functions. I have tried u, v as polylines functions, not to avail.

So, we are left with a puzzle of an unknown data set and worst, a data set treated by unknown data reduction before it was passed by the collab. There was in fact no project, neither for Mathcad neither for collaboration. Let it fly in the blue as it came out of the blue.

jmG

[ValeryOchkov]

See
http://twt.mpei.ac.ru/ochkov/car/c_e.html
Val
http://twt.mpei.ac.ru/ochkov/v_ochkov.htm