Nit: C-Style for doesn't handle that very well. STEP 0.5 is ok since it's a sum of powers of 2 (2^-1), but let's take STEP 0.1 instead:

$ perl -E'for (my $_=0; $_<=7; $_+=0.1) { say }'
...
5.6
5.7
5.8
5.9
5.99999999999999
6.09999999999999
6.19999999999999
6.29999999999999
6.39999999999999
6.49999999999999
6.59999999999999
6.69999999999999
6.79999999999999
6.89999999999999
6.99999999999999
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Generate the floats from integers to avoid compounding errors:

$ perl -E'for (0..70) { say $_/10 }'
...
5.6
5.7
5.8
5.9
6
6.1
6.2
6.3
6.4
6.5
6.6
6.7
6.8
6.9
7
[download]