speed up the calculation when using function eot()

[Mew-YL]

For downscaling purpose, I have about 4GB MODIS NDVI data and try to use the eot to downscale GIMMS NDVI data, but the calculation speed is too slow with such large dataset( only used 400MB MODIS NDVI data, I already waited for 5 hours ) and I wonder is there any possible ways to accelerate the calculation?

[tim-salabim]

I don't think there's an easy way to speed things up. eot() is already programmed in C++

[Mew-YL]

Can eot() run in parallel processing? just as mentioned in https://strimas.com/post/processing-large-rasters-in-r/

[tim-salabim]

No, parallel processing is not implemented. It has been a long time since we worked on this, but IIRC parallel processing is not feasible, because every pixel in x needs to be regressed against each pixel in y.