Re: [R] cbind, data.frame | numeric to string?
Don't use cbind() -- it forces everything into a single type, here
string, which in turn becomes factor.
Simply,
data.frame(a, b, c)
Like David mentioned a few days ago, I have no idea who is promoting
this data.frame(cbind(...)) idiom, but it's a terrible idea (albeit
one that seems to be very frequent over the last few weeks)
Michael
On Tue, Apr 10, 2012 at 10:33 AM, Anser Chen anser.c...@gmail.com wrote:
Complete newbie to R -- struggling with something which should be pretty
basic. Trying to create a simple data set (which I gather R refers to as a
data.frame). So
a - c(1,2,3,4,5);
b - c(0.3,0.4,0.5,0,6,0.7);
Stick the two together into a data frame (call test) using cbind
test - data.frame(cbind(a,b))
Seems to do the trick:
test
a b
1 1 0.3
2 2 0.4
3 3 0.5
4 4 0.6
5 5 0.7
Confirm that each variable is numeric:
is.numeric(test$a)
[1] TRUE
is.numeric(test$b)
[1] TRUE
OK, so far so good. But, now I want to merge in a vector of characters:
c - c('y1,y2,y3,y4,y5)
Confirm that this is string:
is.numeric(c);
[1] FALSE
cbind c into the data frame:
test - data.frame(cbind(a,b,c))
Looks like everything is in place:
test
a b c
1 1 0.3 y1
2 2 0.4 y2
3 3 0.5 y3
4 4 0.6 y4
5 5 0.7 y5
Except that it seems as if the moment I cbind in a character vector, it
changes numeric data to string:
is.numeric(test$a)
[1] FALSE
is.numeric(test$b)
[1] FALSE
which would explain why the operations I'm trying to perform on elements of
a and b columns are failing. If I look at the structure of the data.frame,
I see that in fact *all* the variables are being entered as factors.
str(test)
'data.frame': 5 obs. of 3 variables:
$ a: Factor w/ 5 levels 1,2,3,4,..: 1 2 3 4 5
$ b: Factor w/ 5 levels 0.3,0.4,0.5,..: 1 2 3 4 5
$ c: Factor w/ 5 levels y1,y2,y3,..: 1 2 3 4 5
But, if I try
test - data.frame(cbind(a,b))
str(test)
'data.frame': 5 obs. of 2 variables:
$ a: num 1 2 3 4 5
$ b: num 0.3 0.4 0.5 0.6 0.7
a and b are coming back as numeric. So, why does cbind'ing a column of
character variables change everything else? And, more to the point, what do
I need to do to 'correct' the problem (i.e., stop this from happening).
[[alternative HTML version deleted]]
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] cbind, data.frame | numeric to string?
Still didn't work for me without cbind , although you really don't need it ;)
worked after i set options(stringsAsFactors=F).
options(stringsAsFactors=F)
df-data.frame(intVec,chaVec)
df
intVec chaVec
1 1 a
2 2 b
3 3 c
df$chaVec
[1] a b c
documentation of data.frame says the option is true by default.
Am 10.04.2012 um 17:38 schrieb R. Michael Weylandt:
Don't use cbind() -- it forces everything into a single type, here
string, which in turn becomes factor.
Simply,
data.frame(a, b, c)
Like David mentioned a few days ago, I have no idea who is promoting
this data.frame(cbind(...)) idiom, but it's a terrible idea (albeit
one that seems to be very frequent over the last few weeks)
Michael
On Tue, Apr 10, 2012 at 10:33 AM, Anser Chen anser.c...@gmail.com wrote:
Complete newbie to R -- struggling with something which should be pretty
basic. Trying to create a simple data set (which I gather R refers to as a
data.frame). So
a - c(1,2,3,4,5);
b - c(0.3,0.4,0.5,0,6,0.7);
Stick the two together into a data frame (call test) using cbind
test - data.frame(cbind(a,b))
Seems to do the trick:
test
a b
1 1 0.3
2 2 0.4
3 3 0.5
4 4 0.6
5 5 0.7
Confirm that each variable is numeric:
is.numeric(test$a)
[1] TRUE
is.numeric(test$b)
[1] TRUE
OK, so far so good. But, now I want to merge in a vector of characters:
c - c('y1,y2,y3,y4,y5)
Confirm that this is string:
is.numeric(c);
[1] FALSE
cbind c into the data frame:
test - data.frame(cbind(a,b,c))
Looks like everything is in place:
test
a b c
1 1 0.3 y1
2 2 0.4 y2
3 3 0.5 y3
4 4 0.6 y4
5 5 0.7 y5
Except that it seems as if the moment I cbind in a character vector, it
changes numeric data to string:
is.numeric(test$a)
[1] FALSE
is.numeric(test$b)
[1] FALSE
which would explain why the operations I'm trying to perform on elements of
a and b columns are failing. If I look at the structure of the data.frame,
I see that in fact *all* the variables are being entered as factors.
str(test)
'data.frame': 5 obs. of 3 variables:
$ a: Factor w/ 5 levels 1,2,3,4,..: 1 2 3 4 5
$ b: Factor w/ 5 levels 0.3,0.4,0.5,..: 1 2 3 4 5
$ c: Factor w/ 5 levels y1,y2,y3,..: 1 2 3 4 5
But, if I try
test - data.frame(cbind(a,b))
str(test)
'data.frame': 5 obs. of 2 variables:
$ a: num 1 2 3 4 5
$ b: num 0.3 0.4 0.5 0.6 0.7
a and b are coming back as numeric. So, why does cbind'ing a column of
character variables change everything else? And, more to the point, what do
I need to do to 'correct' the problem (i.e., stop this from happening).
[[alternative HTML version deleted]]
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
[[alternative HTML version deleted]]
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] cbind, data.frame | numeric to string?
cbind() works as well, but only if c is attached to the existing test variable:
tst - cbind( test, c )
tst
ab c
1 1 0.3 y1
2 2 0.4 y2
3 3 0.5 y3
4 4 0.6 y4
5 5 0.7 y5
str( tst )
'data.frame': 5 obs. of 3 variables:
$ a: num 1 2 3 4 5
$ b: num 0.3 0.4 0.5 0.6 0.7
$ c: Factor w/ 5 levels y1,y2,y3,..: 1 2 3 4 5
Not saying it is a good idea, though...
Rainer
On Tuesday 10 April 2012 11:38:51 R. Michael Weylandt wrote:
Don't use cbind() -- it forces everything into a single type, here
string, which in turn becomes factor.
Simply,
data.frame(a, b, c)
Like David mentioned a few days ago, I have no idea who is promoting
this data.frame(cbind(...)) idiom, but it's a terrible idea (albeit
one that seems to be very frequent over the last few weeks)
Michael
On Tue, Apr 10, 2012 at 10:33 AM, Anser Chen anser.c...@gmail.com wrote:
Complete newbie to R -- struggling with something which should be pretty
basic. Trying to create a simple data set (which I gather R refers to as a
data.frame). So
a - c(1,2,3,4,5);
b - c(0.3,0.4,0.5,0,6,0.7);
Stick the two together into a data frame (call test) using cbind
test - data.frame(cbind(a,b))
Seems to do the trick:
test
a b
1 1 0.3
2 2 0.4
3 3 0.5
4 4 0.6
5 5 0.7
Confirm that each variable is numeric:
is.numeric(test$a)
[1] TRUE
is.numeric(test$b)
[1] TRUE
OK, so far so good. But, now I want to merge in a vector of characters:
c - c('y1,y2,y3,y4,y5)
Confirm that this is string:
is.numeric(c);
[1] FALSE
cbind c into the data frame:
test - data.frame(cbind(a,b,c))
Looks like everything is in place:
test
a b c
1 1 0.3 y1
2 2 0.4 y2
3 3 0.5 y3
4 4 0.6 y4
5 5 0.7 y5
Except that it seems as if the moment I cbind in a character vector, it
changes numeric data to string:
is.numeric(test$a)
[1] FALSE
is.numeric(test$b)
[1] FALSE
which would explain why the operations I'm trying to perform on elements of
a and b columns are failing. If I look at the structure of the data.frame,
I see that in fact *all* the variables are being entered as factors.
str(test)
'data.frame': 5 obs. of 3 variables:
$ a: Factor w/ 5 levels 1,2,3,4,..: 1 2 3 4 5
$ b: Factor w/ 5 levels 0.3,0.4,0.5,..: 1 2 3 4 5
$ c: Factor w/ 5 levels y1,y2,y3,..: 1 2 3 4 5
But, if I try
test - data.frame(cbind(a,b))
str(test)
'data.frame': 5 obs. of 2 variables:
$ a: num 1 2 3 4 5
$ b: num 0.3 0.4 0.5 0.6 0.7
a and b are coming back as numeric. So, why does cbind'ing a column of
character variables change everything else? And, more to the point, what do
I need to do to 'correct' the problem (i.e., stop this from happening).
[[alternative HTML version deleted]]
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] cbind, data.frame | numeric to string?
Sorry, I missed that the OP's real question was in character/factor,
not in the why are these all factors bit...good catch.
Rant about cbind() still stands though. :-) [Your way with cbind()
would give him all characters, not some characters and some numerics
since cbind() gives a matrix by default -- note that in Rainer's
construction, it doesn't coerce because it's giving a data.frame (as
cbind.data.frame does but cdbind.default doesn't) so no coercion is
necessary ]
Best,
Michael
On Tue, Apr 10, 2012 at 11:55 AM, Jessica Streicher
j.streic...@micromata.de wrote:
Still didn't work for me without cbind , although you really don't need it ;)
worked after i set options(stringsAsFactors=F).
options(stringsAsFactors=F)
df-data.frame(intVec,chaVec)
df
intVec chaVec
1 1 a
2 2 b
3 3 c
df$chaVec
[1] a b c
documentation of data.frame says the option is true by default.
Am 10.04.2012 um 17:38 schrieb R. Michael Weylandt:
Don't use cbind() -- it forces everything into a single type, here
string, which in turn becomes factor.
Simply,
data.frame(a, b, c)
Like David mentioned a few days ago, I have no idea who is promoting
this data.frame(cbind(...)) idiom, but it's a terrible idea (albeit
one that seems to be very frequent over the last few weeks)
Michael
On Tue, Apr 10, 2012 at 10:33 AM, Anser Chen anser.c...@gmail.com wrote:
Complete newbie to R -- struggling with something which should be pretty
basic. Trying to create a simple data set (which I gather R refers to as a
data.frame). So
a - c(1,2,3,4,5);
b - c(0.3,0.4,0.5,0,6,0.7);
Stick the two together into a data frame (call test) using cbind
test - data.frame(cbind(a,b))
Seems to do the trick:
test
a b
1 1 0.3
2 2 0.4
3 3 0.5
4 4 0.6
5 5 0.7
Confirm that each variable is numeric:
is.numeric(test$a)
[1] TRUE
is.numeric(test$b)
[1] TRUE
OK, so far so good. But, now I want to merge in a vector of characters:
c - c('y1,y2,y3,y4,y5)
Confirm that this is string:
is.numeric(c);
[1] FALSE
cbind c into the data frame:
test - data.frame(cbind(a,b,c))
Looks like everything is in place:
test
a b c
1 1 0.3 y1
2 2 0.4 y2
3 3 0.5 y3
4 4 0.6 y4
5 5 0.7 y5
Except that it seems as if the moment I cbind in a character vector, it
changes numeric data to string:
is.numeric(test$a)
[1] FALSE
is.numeric(test$b)
[1] FALSE
which would explain why the operations I'm trying to perform on elements of
a and b columns are failing. If I look at the structure of the data.frame,
I see that in fact *all* the variables are being entered as factors.
str(test)
'data.frame': 5 obs. of 3 variables:
$ a: Factor w/ 5 levels 1,2,3,4,..: 1 2 3 4 5
$ b: Factor w/ 5 levels 0.3,0.4,0.5,..: 1 2 3 4 5
$ c: Factor w/ 5 levels y1,y2,y3,..: 1 2 3 4 5
But, if I try
test - data.frame(cbind(a,b))
str(test)
'data.frame': 5 obs. of 2 variables:
$ a: num 1 2 3 4 5
$ b: num 0.3 0.4 0.5 0.6 0.7
a and b are coming back as numeric. So, why does cbind'ing a column of
character variables change everything else? And, more to the point, what do
I need to do to 'correct' the problem (i.e., stop this from happening).
[[alternative HTML version deleted]]
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
[[alternative HTML version deleted]]
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] cbind, data.frame | numeric to string?
On Apr 10, 2012, at 11:58 AM, Rainer Schuermann wrote:
cbind() works as well, but only if c is attached to the existing
test variable:
tst - cbind( test, c )
tst
ab c
1 1 0.3 y1
2 2 0.4 y2
3 3 0.5 y3
4 4 0.6 y4
5 5 0.7 y5
str( tst )
'data.frame': 5 obs. of 3 variables:
$ a: num 1 2 3 4 5
$ b: num 0.3 0.4 0.5 0.6 0.7
$ c: Factor w/ 5 levels y1,y2,y3,..: 1 2 3 4 5
Not saying it is a good idea, though...
To be somewhat more expansive ... 'cbind' is not just one function,
but rather a set of functions, since it is generic. The one that is
chosen by the interpreter will depend on whether the first argument
has a class. If it does have a class as in the example above having a
class of data.frame, then the cbind.data.frame function will be
dispatched to process the list of arguments. If the first argument
doesn't have a class as in the OP's second example below, then the
internal cbind function will be used and returns a matrics which
strips off all but a few attributes and forces a lowest common
denominator mode. If only one of the arguments were logical, then
cbind would return a a matrix of all TRUEs and FALSEs.
(This all assumes that the typos in the OP's original example that
created 'c' as an incomplete expression and a and b with unequal
lengths were fixed.)
a - c(1,2,3,4,5);
b - c(0.3,0.4,0.5,0,6,0.7);
test - data.frame(cbind(a,b))
Warning message:
In cbind(a, b) :
number of rows of result is not a multiple of vector length (arg 1)
c - c(y1,y2,y3,y4,y5)
cbind(c, test)
Error in data.frame(..., check.names = FALSE) :
arguments imply differing number of rows: 5, 6
--
David.
Rainer
On Tuesday 10 April 2012 11:38:51 R. Michael Weylandt wrote:
Don't use cbind() -- it forces everything into a single type, here
string, which in turn becomes factor.
Simply,
data.frame(a, b, c)
Like David mentioned a few days ago, I have no idea who is promoting
this data.frame(cbind(...)) idiom, but it's a terrible idea (albeit
one that seems to be very frequent over the last few weeks)
Michael
On Tue, Apr 10, 2012 at 10:33 AM, Anser Chen anser.c...@gmail.com
wrote:
Complete newbie to R -- struggling with something which should be
pretty
basic. Trying to create a simple data set (which I gather R refers
to as a
data.frame). So
a - c(1,2,3,4,5);
b - c(0.3,0.4,0.5,0,6,0.7);
Stick the two together into a data frame (call test) using cbind
test - data.frame(cbind(a,b))
Seems to do the trick:
test
a b
1 1 0.3
2 2 0.4
3 3 0.5
4 4 0.6
5 5 0.7
Confirm that each variable is numeric:
is.numeric(test$a)
[1] TRUE
is.numeric(test$b)
[1] TRUE
OK, so far so good. But, now I want to merge in a vector of
characters:
c - c('y1,y2,y3,y4,y5)
Confirm that this is string:
is.numeric(c);
[1] FALSE
cbind c into the data frame:
test - data.frame(cbind(a,b,c))
Looks like everything is in place:
test
a b c
1 1 0.3 y1
2 2 0.4 y2
3 3 0.5 y3
4 4 0.6 y4
5 5 0.7 y5
Except that it seems as if the moment I cbind in a character
vector, it
changes numeric data to string:
is.numeric(test$a)
[1] FALSE
is.numeric(test$b)
[1] FALSE
which would explain why the operations I'm trying to perform on
elements of
a and b columns are failing. If I look at the structure of the
data.frame,
I see that in fact *all* the variables are being entered as
factors.
str(test)
'data.frame': 5 obs. of 3 variables:
$ a: Factor w/ 5 levels 1,2,3,4,..: 1 2 3 4 5
$ b: Factor w/ 5 levels 0.3,0.4,0.5,..: 1 2 3 4 5
$ c: Factor w/ 5 levels y1,y2,y3,..: 1 2 3 4 5
But, if I try
test - data.frame(cbind(a,b))
str(test)
'data.frame': 5 obs. of 2 variables:
$ a: num 1 2 3 4 5
$ b: num 0.3 0.4 0.5 0.6 0.7
a and b are coming back as numeric. So, why does cbind'ing a
column of
character variables change everything else? And, more to the
point, what do
I need to do to 'correct' the problem (i.e., stop this from
happening).
[[alternative HTML version deleted]]
David Winsemius, MD
West Hartford, CT
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] cbind, data.frame | numeric to string?
On Apr 10, 2012, at 12:19 PM, David Winsemius wrote:
On Apr 10, 2012, at 11:58 AM, Rainer Schuermann wrote:
cbind() works as well, but only if c is attached to the existing
test variable:
tst - cbind( test, c )
tst
ab c
1 1 0.3 y1
2 2 0.4 y2
3 3 0.5 y3
4 4 0.6 y4
5 5 0.7 y5
str( tst )
'data.frame': 5 obs. of 3 variables:
$ a: num 1 2 3 4 5
$ b: num 0.3 0.4 0.5 0.6 0.7
$ c: Factor w/ 5 levels y1,y2,y3,..: 1 2 3 4 5
Not saying it is a good idea, though...
To be somewhat more expansive ... 'cbind' is not just one function,
but rather a set of functions, since it is generic. The one that
is chosen by the interpreter will depend on whether the first
argument has a class.
That was just my erroneous impression. If _any_ of the objects in the
argument list is a data.frame then cbind.data.frame appears to get
used. There is a Dispatch section on the help page for cbind that
appears to cover this adequately.
If it does have a class as in the example above having a class of
data.frame, then the cbind.data.frame function will be dispatched
to process the list of arguments. If the first argument doesn't have
a class as in the OP's second example below, then the internal cbind
function will be used and returns a matrics which strips off all but
a few attributes and forces a lowest common denominator mode. If
only one of the arguments were logical, then cbind would return a a
matrix of all TRUEs and FALSEs.
(This all assumes that the typos in the OP's original example that
created 'c' as an incomplete expression and a and b with unequal
lengths were fixed.)
a - c(1,2,3,4,5);
b - c(0.3,0.4,0.5,0,6,0.7);
test - data.frame(cbind(a,b))
Warning message:
In cbind(a, b) :
number of rows of result is not a multiple of vector length (arg 1)
c - c(y1,y2,y3,y4,y5)
cbind(c, test)
Error in data.frame(..., check.names = FALSE) :
arguments imply differing number of rows: 5, 6
--
David.
Rainer
On Tuesday 10 April 2012 11:38:51 R. Michael Weylandt wrote:
Don't use cbind() -- it forces everything into a single type, here
string, which in turn becomes factor.
Simply,
data.frame(a, b, c)
Like David mentioned a few days ago, I have no idea who is promoting
this data.frame(cbind(...)) idiom, but it's a terrible idea (albeit
one that seems to be very frequent over the last few weeks)
Michael
On Tue, Apr 10, 2012 at 10:33 AM, Anser Chen
anser.c...@gmail.com wrote:
Complete newbie to R -- struggling with something which should be
pretty
basic. Trying to create a simple data set (which I gather R
refers to as a
data.frame). So
a - c(1,2,3,4,5);
b - c(0.3,0.4,0.5,0,6,0.7);
Stick the two together into a data frame (call test) using cbind
test - data.frame(cbind(a,b))
Seems to do the trick:
test
a b
1 1 0.3
2 2 0.4
3 3 0.5
4 4 0.6
5 5 0.7
Confirm that each variable is numeric:
is.numeric(test$a)
[1] TRUE
is.numeric(test$b)
[1] TRUE
OK, so far so good. But, now I want to merge in a vector of
characters:
c - c('y1,y2,y3,y4,y5)
Confirm that this is string:
is.numeric(c);
[1] FALSE
cbind c into the data frame:
test - data.frame(cbind(a,b,c))
Looks like everything is in place:
test
a b c
1 1 0.3 y1
2 2 0.4 y2
3 3 0.5 y3
4 4 0.6 y4
5 5 0.7 y5
Except that it seems as if the moment I cbind in a character
vector, it
changes numeric data to string:
is.numeric(test$a)
[1] FALSE
is.numeric(test$b)
[1] FALSE
which would explain why the operations I'm trying to perform on
elements of
a and b columns are failing. If I look at the structure of the
data.frame,
I see that in fact *all* the variables are being entered as
factors.
str(test)
'data.frame': 5 obs. of 3 variables:
$ a: Factor w/ 5 levels 1,2,3,4,..: 1 2 3 4 5
$ b: Factor w/ 5 levels 0.3,0.4,0.5,..: 1 2 3 4 5
$ c: Factor w/ 5 levels y1,y2,y3,..: 1 2 3 4 5
But, if I try
test - data.frame(cbind(a,b))
str(test)
'data.frame': 5 obs. of 2 variables:
$ a: num 1 2 3 4 5
$ b: num 0.3 0.4 0.5 0.6 0.7
a and b are coming back as numeric. So, why does cbind'ing a
column of
character variables change everything else? And, more to the
point, what do
I need to do to 'correct' the problem (i.e., stop this from
happening).
[[alternative HTML version deleted]]
David Winsemius, MD
West Hartford, CT
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
David Winsemius, MD
West Hartford, CT
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
