Re: [LUG] Excel mangles genes draft letter

[Simon Waters <simon@xxxxxxxxxxxxxxxxxxxx>]

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John Daragon wrote:
| On Wednesday 21 July 2004 10:24, Adrian Midgley wrote:
|
|>Perhaps a reasonable design aim might be to separate
|>the display format from the underlying data, which would avoid this entire
|>class of accidents being possible.
|
|
| No it *wouldn't*. That's exactly what Excel does in this case, and
exactly
| what these users failed to expect. SEPT02 is interpreted as 02SEP04 and
| stored as 38232 (from whence it's pretty trivial to reconstruct SEPT02
if you
| need to).

The irreversible corruption in the paper was referring to data Excel
incorrectly guessed to be floating point numbers, not dates.

However the reconstruction of dates would only work if there was a one
to one mapping between string and date, this will not always be the case
(as many strings map to the same date). So there is potential for data
loss from this transform as well, although less likely.

Presumably a preferred behaviour is to do no transform till someone
explicitly identifies data via a format command, i.e. make the user do
the right thing (TM). Or perform transforms only when an appropriate
operation is applied - such as "typeless" (or whatever the term is)
programming languages do.

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