Thanks Davis. But actually, the line is legitimate:
if (inherits(wt,what="character")) wt<-data[,wt]
because, coming down with wt being characters, the part wt<-data[,wt]
then picks up variables data$wt. The call
wmean(mydata,wt="weight")
actually goes OK. I was hoping to figure out a way to fix the wmean
routine some how so that I can call with
wmean(mydata,wt=weight)
Good to know there is a better way to initialize the vector Mean and and
a better list command. Thank you!
On 6/26/2015 2:39 AM, David Winsemius wrote:
On Jun 25, 2015, at 7:48 PM, Steven Yen wrote:
Thanks to all for the help. I have learned much about "inherit" and "class". I
like to know about one additional option, and that is to use a calling parameter without the
quotation marks, similar to the linear regression syntax:
lm(data=mydata,weights=wt)
Below is a simple set of codes to calculate weighted means with generated data in data
frame "mydata". As annotated below, I like the following call to work (without
the quotations):
wmean(mydata,wt=weight)
Let's start with the call. If you are to execute this, then names `mydata` and
`weight` each must have a value.
Thank you!
----
mydata<-matrix(1:20,ncol=2)
OK. There is a value having been assigned to `mydata`
mydata<-cbind(mydata,runif(10,0,1))
And now augmented.
colnames(mydata)<-c("y","x","weight")
And a names attribute added for its columns.
mydata<-as.data.frame(mydata)
wmean <- function(data,wt){
if (inherits(wt,what="character")) wt<-data[,wt]
wt<-wt/mean(wt)
Here's the problem. If `wt` was of mode "character", then you cannot divide it
by a number, since the RHS will be evaluated first. You really should read the error
messages!
Perhaps you meant:
wt <- data[, wt]/mean(data[ , wt]
But if you did, then it's rather confusing (but possible) to assign the value
to the same name as the column of the matrix.
Mean<-NULL
Why do that? If you remove it from the workspace then you cannot assign a value
using indexed assignment as you apparently intend to do. Should have been
Mean <- numeric( ncol(data) )
for (i in 1:ncol(data)){
Mean[i] <- sum(data[,i]*wt)/sum(wt)
There is a bit of a confusion here. `wt` started out as a character value. I
guess you could do this.
}
list("Mean: ",Mean)
Wrong syntax for lists. Suspect you want
list(Mean=Mean)
}
wmean(mydata,wt="weight") # This works
wmean(mydata,wt=weight) # <= Like this to work
So were you planning to execute this first?
weight="weight" #?
--
Steven Yen
My e-mail alert:
https://youtu.be/9UwEAruhyhY?list=PLpwR3gb9OGHP1BzgVuO9iIDdogVOijCtO
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