commuteDistance error (gdistance)

Thu, Sep 28, 2017 9:40 AM

Hello,

I am trying to estimate random walk resistance distances with
commuteDistance() function from the package gdistance. However, with some
of my rasters I've encountered this error:

Error in LU.dgC(a) : cs_lu(A) failed: near-singular A (or out of memory)

Sometimes it happens right away after I hit enter, in others the command
will run for along time (ca. 30 min) and hog up > 3 GB of memory, then halt
with this error. I'm wondering what may be causing the error?

I am building my transition objects with:

tr <- transition(ras, function(x) 1/mean(x), 8)

"ras" would be an irregularly shaped raster with resistance values ranging
from 1 to 10. The raster's CRS is "+proj=utm +zone=11 ellps=WGS84
+ellps=WGS84".

Any help is appreciated!

Thanks,
Santiago

==========================
Santiago Sanchez-Ramirez, PhD
Postdoctoral Associate
Ecology and Evolutionary Biology
University of Toronto
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