r.mapcalc, floating-point

[Joe Marlow]

When performing floating-point arithmetic on image data with r.mapcalc, the
result files inflate by a factor of four of the original file size.  I checked
the file headers and found that the result files have 4 bytes per cell instead
of 1 byte per cell as in the original image files. This is the case even
though the cell values are integers.  Does anyone know how I can get result
files that have one byte per cell? I don't have room on my disk to store
the huge files, but I need to perform floating-point operations on the images.
Thanks in advance for the help.