how to dump freeform coordinates (a plot shape)

[Durango]

Help sais: Display cell contents in a shape or text box
Click the AutoShape or text box you want to link.
In the formula bar, type an equal sign (=).
Click the worksheet cell that contains the data or text you want to link to.
Press ENTER.
Note You cannot use this procedure in a freeform, scribble, line,
-> but this is what I want! I want to process the line data.
I have a coarse set of x,y data that look nice when I get a shape between
the point, not just straight lines between points. How can I get/dump an
improved/ more dense set of coordinates positioned at the smooth shape?

This Q is for a preliminary solution (my set of x,y data came from a CAD
program), my real problem is that I have the perfect shape in AutoCad, but I
don't know how to dump out coordinates for that line either.

 

[Andy Pope]

Hi,

You are misunderstanding what linking the shape to a cell does.
It simply displays the contents of the linked cell in the shapes textframe.

The information in the cell does not in any way determine the shape or it's
appearance.

You can output the coordinates of nodes in a shape but it will not
interpolate between values.

Cheers
Andy

 

[Jon Peltier]

First of all, the help topic you are reading describes how to use the shape
as a label, using text from a particular cell.

Second, a chart plots the data you provide it, so you'll have to figure out
how to provide unknown coordinates.

- Jon

 

[Durango]

re: " unknown coordinates" - they are unknown to me, but not to Excel that
plots them; how do I get the values that are plotted between my known points?
(ex: I have coord every foot, I want every inch along the line; is there a
dump feature for the nice curved lines that excel plots?)

 

[Shane Devenshire]

Hi,

As far as I know the answer is no. If you know the equation of the line as
calculated in the CAD program you could use that formula in Excel to generate
the intervening datapoints. Or, and probably less satifactory, you could
have Excel calculate a function for the given datapoints and then use that to
estimate the missing points. (see the TREND function) You could possibly do
this with the LINEST (or LOGEST) function or by using the Trendline feature
on that chart, while asking Excel to display the equation of the trendline.

If this helps, please click the Yes button

Cheers,
Shane Devenshire

 

[Jon Peltier]

There is no way to extract the data directly, and in any case it's unlikely
to conform to any particular physical representation of your model.

If you really want to get some numbers, you can try this. Brian Murphy has
determined that the smoothed lines are represented by bezier curves. More
details here:
http://www.xlrotor.com/Smooth_curve_bezier_example_file.zip

- Jon

 

[Durango]

Thanks all for your advice. Excel was actually able to give me a physical
representation of my model with use of Autoshape/ line freeform by clicking
at known points along my snaked line, but as you say, it is not possible to
dump out the Bezier representation at equidistant points along the line that
can be seen in a plot.

I did however solve my problem by using a program that reads the *.dwg
format(AutoCad). A trial of Rhino can be download at:
http://www.rhino3d.com/ (but I bought it)
Rhino can dump coordinates for a pipeline analysis. The procedure is as
follows:
- Inactivate all layer (light bulb sign on the layer panel on the right).
The blue colour is inactive and yellow is active.
- Activate the line
- Go to Curve in the main manual
- select point object
- select divide curve by length of segment (give your preferred length)
- Go to Curve - Point cloud - create point cloud - select all points
- save output as a point file