title: Changing the extent and resolution of raster layers in R for successful stacking
body: <p>I am trying to create a species distribution model in R. I have created raster layers in ArcMap and have imported them into R. They cannot be stacked unless the extents are exactly the same and they all have the same number of rows and columns. </p>
  
  <p>However, when I alter these factors to successfully stack them they lose all their values and my stacked data frame is just filled with NAs.</p>
  
  <p>Does anyone know how I can alter the extent and resolution of my raster layers so they can be successfully stacked -- so I can then attach environmental info to presence points.</p>
  
  <p>Cheers</p>