I'm no expert in R internals or floating point computation, however, two
things come to mind.
First, I suspect the exact value is stored. It is just the printing that looks
rounded. That is likely because 0.001 completely dominates the rest. To print in
full precision, you would need over 200 digits for some of your values.
Second, you may be pushing the limits of precision. It seems to me your original
values are indistinguishable from zero. If they really represent materially
different values, you might want to rescale them to improve computational
reliability.
--
Kevin E. Thorpe
Head of Biostatistics, Applied Health Research Centre (AHRC)
Li Ka Shing Knowledge Institute of St. Michael's
Assistant Professor, Dalla Lana School of Public Health
University of Toronto
email: kevin.thorpe at utoronto.ca Tel: 416.864.5776 Fax: 416.864.3016
?On 2019-03-08, 7:39 AM, "R-help on behalf of akshay kulkarni"
<r-help-bounces at r-project.org on behalf of akshay_e4 at hotmail.com>
wrote:
dear members....
here is a piece of my code:
> tail(YLf14,15)
[1] 5.706871e-217 2.563877e-218 2.823295e-218 2.694622e-222 1.777409e-226
[6] 1.134403e-201 5.269464e-215 2.272121e-219 2.794970e-223 1.630978e-187
[11] 1.721529e-213 5.859815e-178 4.842612e-222 1.333685e-193 1.256051e-174
> YLf16 <- YLf14 + 0.001
> tail(YLf16,15)
[1] 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001
[13] 0.001 0.001 0.001
Is there any way to avoid the rounding off of YLf16 to 0.001, and take exact
values?
very many thanks for your time and effort......
yours sincerely,
AKSHAY M KULKARNI
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