fp and non-fp versions

[Rich Shepard]

On Sun, 26 Mar 2000, Walter Finsinger wrote:

> could someone explain me what's the difference between fp and non-fp
> versions ?. I think it is a kind of essential question for a new user of
> GIS.

Walt,

  The major difference is where the decimal point (or comma for those of you
in Europe) is placed.

  Suppose you have a sites file with soil nitrogen levels measured in an
agricultural field, and you want to build a 3D model of those values. The 3D
surface will allow you to see the distribution of nitrogen over the area of
the field.

  In the pre-floating point version you would have to multiply all your
nitrogen values by some power of 10 to make them integers. When you are done
with all the processing, interpolating, analyzing and displaying, you need
to divide the final numbers by the same power of 10 to restore them to the
correct magnitude. A lot of bookkeeping involved.

  With the floating point version you avoid that extra work.

  On the other hand, not all modules have been ported to the new version 5.
It also has a different file format for data so it may take a while for
everyone to migrate from version 4.x to 5.x.

HTH,

Rich

Dr. Richard B. Shepard, President

                       Applied Ecosystem Services, Inc. (TM)
              Making environmentally-responsible mining happen. (SM)         
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