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[nobody <question685223@xxxxxxxxxxxxxxxxxxxxx>]

Question #685223 on Yade changed:
https://answers.launchpad.net/yade/+question/685223

nobody gave more information on the question:
Hi all,

let me make this more clear, right now I exported some text files. the
file contains the position, radius, and the nine per particle stress
components.

I'm trying to use the following code to output the micro stress
field[1].


###############################################
from yade import ymport, export
vtk = export.VTKExporter("stress")
s=bodyStressTensors()
m = 0
number_of_txtfiles =1634
while m < number_of_txtfiles:
	O.bodies.append(ymport.text("./num"+str(m)+".txt"))
	O.step()
	TW = TesselationWrapper()
	TW.triangulate()
	TW.computeVolumes()
	TW.setState
	for b in O.bodies:
		if isinstance(b.shape,Sphere):
			b.mystress = s[b.id]*4.*pi/3.*b.shape.radius**3/TW.volume(b.id)
			vtk.exportSpheres(ids='all',what=[('pos','b.state.pos'),('stress','b.mystress')],useRef=False)
	m = m +1
########################################
here is the error.

Welcome to Yade 2018.02b 
TCP python prompt on localhost:9000, auth cookie `cuessk'
XMLRPC info provider on http://localhost:21000
Running script calculate-stress.py
Traceback (most recent call last):
  File "/usr/bin/yade", line 182, in runScript
    execfile(script,globals())
  File "calculate-stress.py", line 16, in <module>
    b.mystress = s[b.id]*4.*pi/3.*b.shape.radius**3/TW.volume(b.id)
IndexError: list index out of range
[[ ^L clears screen, ^U kills line. F12 controller, F11 3d view (use h-key for showing help), F10 both, F9 generator, F8 plot. ]]
#############################
I tried the following  attempts:
1) print out some basic particle information 

In [1]: len(O.bodies)
Out[1]: 622

In [2]: b.state.pos
Out[2]: Vector3(0.935164196838,0.38080276367,0.869850258236)

In [3]: b.shape.radius
Out[3]: 0.041134821457

this is the same as the first exported text file.

2) I tried to print out the per particle stress. i.e. the stress I got
by using bodystresstensor.

In [5]: s
Out[5]: []

In [6]: s[b.id]
---------------------------------------------------------------------------
IndexError                                Traceback (most recent call last)
/usr/bin/yade in <module>()
----> 1 s[b.id]

IndexError: list index out of range

In [7]:


this means that particle stress didn't import successfully.  So I checked the yade.ymport.text function, here is the explanation: it says it will load the coordinate from the file.  as for the **kw ((unused keyword arguments) is passed to utils.sphere). I checked the definition of the utils.sphere[3] , it didn't mention particle stress.

#################################
as we all know, we do not have some function like the position (b.state.pos) (this is something like the intrinsic funtion that a particle has, but for the particle stress, we don't have commnad like b.sress or b.state.stress), I think maybe this is the reason why the per particle stress can not import successfully.

besides, I don't know why the list index is out of range.

#########################

thanks,


references
[1]https://yade-dem.org/doc/user.html#microstressandmicrostrain
[2]https://yade-dem.org/doc/yade.ymport.html?highlight=yade%20ymport%20text#yade.ymport.text
[3]https://yade-dem.org/doc/yade.utils.html?highlight=yade%20utils%20sphere#yade.utils.sphere

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