topic Re: Read data from a file in ArcGIS CityEngine Questions

Read data from a file

CharalamposApostolou — Fri, 16 Mar 2012 16:18:58 GMT

Is there a way to read data from a file? I have a document file with some attributes in each line and i want to read some attributes and build objects according to that.

Re: Read data from a file

MatthiasBuehler1 — Mon, 19 Mar 2012 13:42:13 GMT

hi !

it depends on the file type .. what file is it ?

let me know ..

Re: Read data from a file

CharalamposApostolou — Mon, 09 Apr 2012 14:43:41 GMT

Hi. It is just a text file (.txt)

Re: Read data from a file

MatthiasBuehler1 — Tue, 10 Apr 2012 07:49:39 GMT

hi !

to do this, you'd need the CityEngine Advanced version and use it's Python Scripting functionality to 1] parse the file for the content, then 2] assign the values to the shapes.

it may be easier to bring them in via a format which already supports such attribute metadata, such as .shp or Esri's GDB.

what's your source application from where you get the .txt data files ?

Re: Read data from a file

CharalamposApostolou — Mon, 23 Apr 2012 15:05:28 GMT

Thanks very much for the reply,
I created the file. I have some shapes with a number id and in the file according to the id there are informations about the houses that are going to build. The text file is rows and columns with integer numbers. Is there a tutorial to read?

Re: Read data from a file

MatthiasBuehler1 — Mon, 23 Apr 2012 15:51:39 GMT

hi ..

can you post a little example based on 2 shapes with their related text file ?

let me know ..

Re: Read data from a file

CharalamposApostolou — Sun, 03 Jun 2012 07:30:08 GMT

i have a Lot with the name Lot50, and a txt file with the following format:

id     rooms      yard      arch    ....
48     2             0          1
49     1             0          1
50     2             1          0
51     4             0          1

and i want to search in the txt file to find Lot50 and then build in the lot what it describes in the txt file. For example in Lot50 its going to build 2 rooms, a yard and no arch.

Re: Read data from a file

MatthiasBuehler1 — Tue, 05 Jun 2012 16:32:04 GMT

hi !

as follows :

- create a file with you data, e.g. info.txt
- put that file into your project's data folder
- copy the attached python script into your project's scripts folder
- open the script (double click)
- edit the absolute path to your into.txt file so it works on your machine.

- create a shape with StartRule 'Lot' (not Lot50 !)
- open it's Object Attributes tab, right-click into it. create an object attr called 'buildingID', with a float value of 49.

- select your shapes of interest on which you have set all buildingIDs.
- run the python script via F9 (python editor must be active view, click on the code)

what happens is :
- python checks the building ID, which is an object attr you have set for each building.
- the list is parsed until the first entry of the line is the building ID.
- that line is given back
- a new object attr for 'rooms', 'arch' and 'yard' is created with the values given in that line.

once you have those attributes now set, you can access them via CGA. initialize each object attr of interest in the CGA code by using :

attr rooms = 0
attr arch = 0
attr yard = 0

make sure you then POINT TO the object attr value and not to the rule value ( which is initialized with 0 ) using the connection editor in the inspector (the little rectangle icon with the triangle).

let me know if it works or if you have questions !

Re: Read data from a file

CharalamposApostolou — Tue, 05 Jun 2012 18:58:35 GMT

Something is going wrong now. It gives me this exception:

Traceback (most recent call last):
File "<string>", line 1, in <module>
File "C:\Users\Xaralampos Apostolou\CityEngine\Python_Example\scripts\getListData.py", line 38, in <module>
buildingID = int (ce.getAttribute(shape, 'buildingID')) # get building ID
TypeError: int() argument must be a string or a number

at org.python.core.PyException.fillInStackTrace(PyException.java:70)
at java.lang.Throwable.<init>(Throwable.java:181)
at java.lang.Exception.<init>(Exception.java:29)
at java.lang.RuntimeException.<init>(RuntimeException.java:32)
at org.python.core.PyException.<init>(PyException.java:46)
at org.python.core.PyException.<init>(PyException.java:43)
at org.python.core.PyException.<init>(PyException.java:61)
at org.python.core.Py.TypeError(Py.java:195)
at org.python.core.PyInteger.asPyInteger(PyInteger.java:84)
at org.python.core.PyInteger.int_new(PyInteger.java:41)
at org.python.core.PyInteger$exposed___new__.new_impl(Unknown Source)
at org.python.core.PyType.invoke_new_(PyType.java:432)
at org.python.core.PyType.type___call__(PyType.java:1397)
at org.python.core.PyType.__call__(PyType.java:1388)
at org.python.core.PyObject.__call__(PyObject.java:397)
at org.python.core.PyObject.__call__(PyObject.java:401)
at org.python.pycode._pyx70.f$0(C:\Users\Xaralampos Apostolou\CityEngine\Python_Example\scripts\getListData.py:37)
at org.python.pycode._pyx70.call_function(C:\Users\Xaralampos Apostolou\CityEngine\Python_Example\scripts\getListData.py)
at org.python.core.PyTableCode.call(PyTableCode.java:165)
at org.python.core.PyCode.call(PyCode.java:18)
at org.python.core.Py.runCode(Py.java:1204)
at org.python.core.Py.exec(Py.java:1248)
at org.python.pycode._pyx73.f$0(<string>:1)
at org.python.pycode._pyx73.call_function(<string>)
at org.python.core.PyTableCode.call(PyTableCode.java:165)
at org.python.core.PyCode.call(PyCode.java:18)
at org.python.core.Py.runCode(Py.java:1204)
at org.python.core.Py.exec(Py.java:1248)
at org.python.util.PythonInterpreter.exec(PythonInterpreter.java:172)
at org.python.pydev.jython.JythonPlugin.exec(Unknown Source)
at org.python.pydev.jython.JProcess.run(Unknown Source)

Re: Read data from a file

MatthiasBuehler1 — Wed, 06 Jun 2012 09:21:40 GMT

hmm.

what datatype is your buildingID ? did you create it as float or string ? ( CityEngine does not have ints, just floats for use with CGA )

are you in general familiar with Python scripting or is this the first time ?

let me know .. 😉

Re: Read data from a file

CharalamposApostolou — Wed, 06 Jun 2012 12:04:13 GMT

I know only the basics of Python. I set the buildingID to float like you told me.

Re: Read data from a file

MatthiasBuehler1 — Wed, 06 Jun 2012 13:17:33 GMT

it works fine here ..

the try commenting out some things and print the type of buildingID :

buildingID = int (ce.getAttribute(shape, 'buildingID'))
print type(buildingID)

I am not sure if this is really the issue.

what version of CityEngine are you using ?

Re: Read data from a file

CharalamposApostolou — Wed, 06 Jun 2012 13:41:40 GMT

I am using the 2010.3 version

Re: Read data from a file

MatthiasBuehler1 — Wed, 06 Jun 2012 14:02:33 GMT

for me it's working too, in 2010.3, without edits.

are you using all forward slashes in the file paths ? ( '/')

sorry, but it seems you really have to track it down line by line.. it works fine here, so it must something small.

maybe add a screenshot, where I can see ALL the details too, ok ?

Re: Read data from a file

CharalamposApostolou — Wed, 06 Jun 2012 14:12:48 GMT

[ATTACH=CONFIG]14972[/ATTACH]

ok i will try to find whats going on

Re: Read data from a file

CharalamposApostolou — Wed, 06 Jun 2012 14:24:17 GMT

I think am doing something wrong in the second argument of this:
buildingID = int(ce.getAttribute(Shape, 'buildingID'))

did i have to set a path like "/CityEngine/..../buildingID" ?

Re: Read data from a file

MatthiasBuehler1 — Thu, 07 Jun 2012 08:59:53 GMT

hi ..

no, the attribute is just an object attribute, thus it needs no path. it's linked to the shape.

name correct ? no syntax error ? no space at the end or similar ?

did you select the shape while running the script ? if the selection is empty, nothing is done ..

Re: Read data from a file

CharalamposApostolou — Mon, 25 Jun 2012 09:21:26 GMT

Thank you very much for your help. the code worked perfectly. I hadto change something in the directory.

Re: Read data from a file

MatthiasBuehler1 — Mon, 25 Jun 2012 15:57:25 GMT

shaaring, shaaring ! 😉

glad I was able to help !