Node Box 2: Following code tutorial

Dear NodeBox Team,

I am following this tutorial on creating your own node:
http://beta.nodebox.net/wiki/NodeBox_for_Programmers
http://beta.nodebox.net/wiki/Writing_Your_Own_Node

I copy & paste the code into Source and reload, but all I got is always this error with X cross mark on the node. I was wondering what I have done wrong. I checked the example file Chrysant and compare it with my file, I don't see any different. I believe I add the Parameters as suggested (for Chrysant).

The script from you guys are working, but not the one I try to make myself.

Any hint?

Sorry for simple question I am very new on this.

hi,
could you maybe send the error which should appear when "messages" is turned on?
possible answers might be :
- when copy pasting you should be aware that the indentation is still correct.
- you should start from a generator node which has a star in its icon
- upgrade to the latest version, i havent seen the big X crossmark for a while, errors are now shown by diagonal red stripes.
- if none of this helps, send an error..

The error message is:
SyntaxError: ("mismatched input '' expecting EOF", ('', 2, 1, ' from math import sin,cos,pi\n'))

1. I think indentation is still there.
2. Yup, that's the one I am using.
3. Latest version... checked. It is shown with diagonal red stripes.

Thanks Lievn.

Wait...

I looked properly at the code, compare it with the working example, and I think you are right. The code I copy and paste from the website has extra indentation.

It is now working! All I need to do is to get rid of that spacing indentation.

Thank you! Now I know I better type it.

CORRECTION:

Further comparison, not the indentation that caused this error.

I found that the code on the tutorial is actually different:

### Working Code
from nodebox.graphics import Path
from math import sin,cos,pi

def cook(self):
p = Path()
p.fill = None
x0,y0 = 0.0,0.0
scale = 10.0

for i in xrange(self.number):
u = i * 21.0 * pi / self.number;
p4 = sin(17.0 * u / 3.0);
p8 = sin(2.0 * cos(3.0 * u) - 28.0 * u);
r = self.scale*(1.0 + sin(self.texture*u/5.0)) - 4.0*p4*p4*p4*p4 * p8*p8*p8*p8*p8*p8*p8*p8

x1 = r*cos(u)
y1 = r*sin(u)
p.addPoint(x1, y1)
x0,y0 = x1,y1
return p.asGeometry()


### FAIL CODE

from nodebox.graphics import Path
from math import sin,cos,pi

def cook(self):
p = Path()
p.fill = None
x0,y0 = 0.0,0.0
scale = 10.0

for i in xrange(self.number):
u = i * 14.0 * pi / self.number
p4 = sin(17.0 * u / 3.0) ** 4
p8 = sin(4.0 * cos(3.0 * u) - 28.0 * u) ** 8
r = self.scale*(1.0 + sin(self.texture*u/5.0)) - 14.0*p4 * p8

x1 = r*cos(u)
y1 = r*sin(u)
p.addPoint(x1, y1)
x0,y0 = x1,y1
return p.asGeometry().

Now, when I paste the working code, it just works.

Btw,
** 4 and ** 8 looked very peculiar on the FAIL CODE.

Probably the syntax has issue? I am not familiar with the code, so pardon my cluelessness.

Thanks.

I found out the culprit. You are right, it is the indentation, after all. I did not know that the code is so picky on spacing.

When I copy-paste the code, the beginning appears like this:

### see the extra spacing ###

from nodebox.graphics import Path
from math import sin,cos,pi
def cook(self):

I get rid of that extra invisible spacing:

from nodebox.graphics import Path
from math import sin,cos,pi
def cook(self):

The code is now working without issue :)

Cheers for pointing this out.

- Jim

None of the code above will work without indentation. Now it is very clear. Cheers.

hi,
i changed the code blocks on the wiki. you should be able to copy paste code from the website to nodebox without having to worry about indentation level.