Set street width based on (non numeric) object attribute

Question

Hi folks,

I understand that the streetWidth shape parameter is generated when the shape is created.

But is there no way to change it dynamically through CGA coding?

I'd like to set it based on the type of road, as specified in the original network data attribute table; ie 'arterials' would set street width to 20m, 'collectors' to 16 m, etc.

Any suggestions?

thanks!
Tom

NathanBrigmon · Answer

Hi,

but for the street widths it works ?

lemme know..

m.

Yes, it was a strange thing, but I figured out the answer. Not sure why I had to take this route, but I needed to set the attribute source to "OBJECT", because it wasn't completely making the connection. So, I added a few extra lines of code as a fail-safe:
        ce.setAttributeSource(streetsegment, "/ce/street/streetWidth", "OBJECT")
        ce.setAttributeSource(streetsegment, "/ce/street/sidewalkWidthLeft ", "OBJECT")
        ce.setAttributeSource(streetsegment, "/ce/street/sidewalkWidthRight", "OBJECT")

I've made a little progress in my python understanding and have changed my approach. After first selecting the objects from the scene with my specified attributes, I then run the above lines of code in a new context:    selectedSegments = ce.getObjectsFrom(ce.selection())
    for streetsegment  in selectedSegments:
        ce.setAttributeSource(streetsegment, "/ce/street/streetWidth", "OBJECT")
        ce.setAttribute(streetsegment , 'streetWidth', W1)
        ce.setAttributeSource(streetsegment, "/ce/street/sidewalkWidthLeft", "OBJECT")
        ce.setAttribute(streetsegment , 'sidewalkWidthLeft', W2)
        ce.setAttributeSource(streetsegment, "/ce/street/sidewalkWidthRight", "OBJECT")
        ce.setAttribute(streetsegment , '/sidewalkWidthRight', W3)

MatthiasBuehler1 · Answer

Hi,

but for the street widths it works ?

lemme know..

m.

NathanBrigmon · Answer

Hi Matthias,

I have been experimenting with setting the street width based on layer attributes like this:width              = getObjectAttr("StreetType", false)

streetWidthDefault = 7

attr streetWidth =
    case width == "Alley" : 4    * streetscale
    case width == "Arterial" : 12     * streetscale
    case width == "Collector" : 8     * streetscale 
    else           : streetWidthDefault

Unfortunately, this same logic hasn't been working for sidewalk widths... any suggestions?

Here is part of my code:sidewalkr       = getObjectAttr("SidewalkR",false)

attr sidewalkWidthRight = 
    case sidewalkr == "Alley" : 2     * streetscale
    case sidewalkr == "Arterial" : 6     * streetscale
    case sidewalkr == "Collector" : 4     * streetscale 
    else           : streetWidthDefault

For some reason, it has been returning 0 for my sidewalkWidthRight.