NEWS drsmooth 1.9.0

Version 1.9.0 introduces major additional functionality, 
changes several functions' parameters, and implements fixes as follows:

***NEW FEATURES***

- Supports data with dichotomous outcome using new 
required parameter data_type = "continuous" or "dichotomous".  
Outcome proportion is modeled in dichotomous data.
Note: depending on data format, new function drsmooth::expand 
may be required to format summarized dichotomous data 
before executing drsmooth, see example.

- Adds a Fisher's Exact Test to the available tests 
from the noel function, for use with dichotomous data.

- Adds an optional output file of predicted values, 
which may be returned to the user inreal time or written 
to a .csv file.

- Allows user specification of the basis of the spline 
dimensions from the default of 4 to 3.


***MINOR FUNCTION CHANGES & BUG FIXES***

- Function 'smooth' is changed to 'drsmooth' to avoid 
conflict with stats::smooth. 'smooth' is deprecated. 
Please see drsmooth::drsmooth help for details.

- Only the following functions are now exported, 
to come into closer alignment with package development 
best practices:  'prelimstats', 'noel', 'segment', 
'nlbcd', nlaad', 'lbcd', 'expand', 'spline.plot', 'drsmooth'.

- Functions 'noel', 'drsmooth', 'spline.plot',  parameters 
have changed to include data_type. Please see 
drsmooth::<function> help for details.

- Functions 'prelimstats', 'lbcd', 'nlaad', 'nlbcd', 
and 'segment' have not been modified to accommodate 
dichotmous data.

- STD bias calculation in drsmooth may be turned off, 
yielding considerable savings in processing time.

- Step intervals used in predicted data is now 
relative to dose range.


***CURRENT ISSUES & FUTURE FUNCTIONALITY (v.2.0.0)***

- 'drsmooth' calculations are based on the response 
to the lowest dose, even if the dose-response is negative. 
This is maximally conservative and should be interpreted 
carefully, as there is no reason to prefer any dose in 
a non-significant postive (or negative!) initial dose range. 
A more comprehensive solution, including some 
parameterization of absolute change in slope, is underway.

- Include relevant preliminary statistics, additional 
noel tests (e.g. a test for trend in proportions) and 
cut-off dose functionality for dichtomous data.
