Re: [lmi] [lmi-commits] master 7b0b9c3: Make 'InputFundManagementFee' a pure number (not bp)

[Greg Chicares]

On 2018-06-05 16:56, Vadim Zeitlin wrote:
> On Tue,  5 Jun 2018 12:49:08 -0400 (EDT) Greg Chicares <address@hidden> wrote:
[...]
> GC>     Make 'InputFundManagementFee' a pure number (not bp)
> GC>     
> GC>     Redefined this input field to mean a pure number, not a number of 
> basis
> GC>     points. Now all GUI input fields are consistently pure numbers.
> 
>  Wouldn't it be nice to allow entering the number in the UI in bp or,
> maybe, even as either an absolute number, a number in percents or a number
> in bp, e.g. using something like
> 
>       [....0.12] [bp ⇓]
>                     abs
>                     pct
> 
> where the right hand side of the cave painting^W^W ASCII diagram represents
> an opened combobox?

I don't think we'd want a combobox for this. To enter a percentage,
users would type digits on the keyboard and then pick up the mouse
to manipulate the combobox, and that just seems too cumbersome. (We
could tell them how to open a dropdown combobox with Alt-Down, but
they're still going to use the mouse.)

>From time to time I think of allowing text suffixes like '%' and then
parsing "3.5%" as 0.035 . After all, lmi already accepts "3.5e-2" and
stores such a string literally in XML, so it reappears when a saved
file is reopened. We could even use 'bp' or '%%' for permyriad.

That would be kind of like what spreadsheets do. Unfortunately, what
spreadsheets actually do is pretty hairy. For example, the ms 'excel'
spreadsheet does this when a number is entered in a "percentage" cell:

https://www.microsoft.com/en-us/microsoft-365/blog/2011/08/02/how-to-do-percentages-in-excel/
| Numbers equal to and larger than 1 are converted to percentages by
| default; numbers smaller than 1 that are not preceded with a zero
| are multiplied by 100 to convert them to percentages. For example,
| if you type 10 or .1 in a preformatted cell, you’ll see 10% appear
| in the cell. (Now, if you type 0.1 in the cell, something different
| happens. If you want details, see ...

The problem with doing what spreadsheets do is that we'd have to
emulate what spreadsheets actually do, which is a lot of work...and
someone will still insist that the behavior is wrong.