how to draw a scketch with a curve equation?? 1

[DiaaHamdy]

If I have an equation of a curve consider it a circle equation x^2+Y^2=r how can I draw it??
and if I have a coardinates of a curve like I have an excel sheet of X and Y how can I import it to the NX..

Thanks

 

[mmauldin]

For the equation, you need separate expression for x and y.

For the attached example:

r = 1

t = 0

xt = sin(r*t*360)

yt = cos(r*t*360)

where r = the radius, 360 = degrees of a full circle, and t is variable tha NX evaluates from 0 to 1.

Then create a law curve (Insert>Curve>Law curve) where x and y are "by equation" using xt and yt, and z is constant (in this case 0).

 

[mmauldin]

For points from a excel file, you need to export the data in a space delimited format with values for x, y and z and name the file sing a .dat suffix. Then use Insert>Curve>Spline>Though points>Points from file to create the curve.

 

[mmauldin]

"sing" should be "using"

The file should look something like this when opened in Notepad.

0 0 0
1 1 0
2 0 0
3 -1 0
4 0 0

 

[JohnRBaker]

Note that for NX 8.5 we have added a new general purpose, 'File -> Import -> Points From a File' routine, which will support several different file formats as long as they contain fields representing the XYZ coordinates of the points. By this I mean that the it can be either space-delimited, comma-delimited, etc. Also this routine will automatically ignore any lines of data/text which does not meet the criteria (after notifying the user of this fact) which is useful in that as long as the file has a section which contains the point data in an appropriate format these will be read and used to create points even as the other non-point data/text is being ignored.

One example of this is where you might be given the .txt version of an .stl file (many modeling systems, including NX, provides the option to export these rapid-prototyping files as either binary or ASCII data) which can then be read by this new routine thus helping you to 'reverse-engineer' rapid-prototyping data into a set of 3D points which could them be used by the also newly enhanced NX 8.5 version of the 'Fit Surface' function that now accepts either a faceted model OR a 'cloud of points' to 'fit' a surface through.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

 

[mtwheeldon]

Shouldn't the parametric equations be;

xt = sqrt(r)*cos(t*360) and
yt = sqrt(r)*sin(t*360) ?

Suppose the reversal of sin & cos doesn't really matter for a circle, as long as it's consistant with your co-ordinate system but shouldn't the r be square-rooted to match the r in DiaaHamdy's equation? And the way you have it, with the r inside the sin/cos terms, changing the radius won't actually affect the size of the circle.

Realise this post isn't really about parametric equations of a circle, but just thought I should point it out anyway!

 

[DiaaHamdy]

thanks guys you really made my day :$

 

[mmauldin]

Once again, typing faster than I'm thinking. But if you know "r", it's xt=r*cos(t*360), not the square root of r.

 

[mtwheeldon]

Ah yes, sorry - I was basing my equations on the 'r' in the original equation x^2+Y^2=r.