Dear Prof Neuwirth,
my comments were intended mainly to implement some functionality for
complete *R newbies*, that is for persons who do not know how to work in
R. [It is debatable then if they need factors for example, but for the
sake of completion, I mentioned those elements.]
I imagined the following three scenarios:
1. (for comment c)
I encountered often variables that were NOT limited to a single column:
e.g. age was written both in columns A, B, C and D. Therefore, I would
like to be able to select a range individually for every variable:
age: A1:D50
Similarly, Blood Pressure: H1:I100
The A1:H100 selection won't work in this case, because this is not a
data frame as the same data is split into columns. Rewriting the data
into a single column is time-consuming (and the data is often written in
more than one column because of another factor, so rewriting it into a
single column will loose some information).
2. (comment b)
I had in mind the:
fisher.test( matrix( c(number_1, number_2, number_3, number_4), 2 ))
and similar contingency tables. Somebody who does NOT have any idea of
R, won't be able to perform such a simple test until he learns to
construct a matrix. BUT if the user only needs the fisher test, then ,
you are right, there is no real need for the user to create a matrix on
his own; it is easy to select the contingency table and to pass the
correct command to R (without the user having to know more details about
matrices).
3. (comment a)
The previous comment applies to factors, too. I had primary in mind the
ANOVA test, but then again, the user does not need to know the details
of parsing the arguments and everything could be hidden in the
implementation. Somebody who needs factors for a different analysis,
will most likely know how to create them in R.
Unfortunately, I am a little bit limited when judging RExcel:
- first, I work a lot with R, so I am not a newbie, BUT I try to think
what a newbie might want; this may sometimes backfire
- secondly, I work with R mostly at home; however, I do not use Excel at
home
Well, the issues I described were meant to allow newbies to perform some
specific tests, but it is debatable if such a newbie does indeed need to
know and use those details (those issues could be implemented/hidden in
specific menu commands).
Sincerely,
Leonard
Erich Neuwirth wrote:
Sorry for not answering earlier.
You mention some open issues.
Let me ask some more questions to clarify these.
Leonard Mada wrote:
Dear Prof. Neuwirth,
depth). Mainly three issues remained uncovered: a.) converting input
data/vectors to factors (is useful sometimes),
It you transfer a variable to R and then just apply the function factor
in R, it is converted to a factor.
Do you need more functionality?
b.) importing data as
matrices (for contingency tables, e.g. for a Fisher exact test) and
I assume by importing you mean import into the spreadsheet.
The basic unit for data transfer in our framework is an array
of a single underlying scalar type. (character, (real) number,
complex number, time&date). So transferring a matrix in either direction
is there. There is, however, one major concern.
Spreadsheet programs don't care too much about missing values.
I have not looked into the details of this in Calc, but I think
that it is important to be careful about this problem in the interface.
c.)
converting a data range to multiple vectors vs independently selecting
the data ranges for the multiple vectors.
When a range is transferred as a dataframe, in R you can immediately
access the columns as vectors. What kind of additional functionality
do you think is needed?
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