Re: [R] multiple imputation with fit.mult.impute in Hmisc - how to replace NA with imputed value?

2008-11-26 Thread Frank E Harrell Jr

Charlie Brush wrote:

Frank E Harrell Jr wrote:

Charlie Brush wrote:

I am doing multiple imputation with Hmisc, and
can't figure out how to replace the NA values with
the imputed values.

Here's a general ourline of the process:

 > set.seed(23)
 > library("mice")
 > library("Hmisc")
 > library("Design")
 > d <- read.table("DailyDataRaw_01.txt",header=T)
 > length(d);length(d[,1])
[1] 43
[1] 2666
Do for this data set, there are 43 columns and 2666 rows

Here is a piece of data.frame d:
 > d[1:20,4:6]
 P01  P02  P03
1  0.1 0.16 0.16
2   NA 0.00 0.00
3   NA 0.60 0.04
4   NA 0.15 0.00
5   NA 0.00 0.00
6  0.7 0.00 0.75
7   NA 0.00 0.00
8   NA 0.00 0.00
9  0.0 0.00 0.00
10 0.0 0.00 0.00
11 0.0 0.00 0.00
12 0.0 0.00 0.00
13 0.0 0.00 0.00
14 0.0 0.00 0.00
15 0.0 0.00 0.03
16  NA 0.00 0.00
17  NA 0.01 0.00
18 0.0 0.00 0.00
19 0.0 0.00 0.00
20 0.0 0.00 0.00

These are daily precipitation values at NCDC stations, and
NA values at station P01 will be filled using multiple
imputation and data from highly correlated stations P02 and P08:

 > f <- aregImpute(~ I(P01) + I(P02) + I(P08), 
n.impute=10,match='closest',data=d)

Iteration 13
 > fmi <- fit.mult.impute( P01 ~ P02 + P08 , ols, f, d)

Variance Inflation Factors Due to Imputation:

Intercept   P02   P08
   1.01  1.39  1.16

Rate of Missing Information:

Intercept   P02   P08
   0.01  0.28  0.14

d.f. for t-distribution for Tests of Single Coefficients:

Intercept   P02   P08
242291.18116.05454.95
 > r <- apply(f$imputed$P01,1,mean)
 > r
   2 3 4 5 7 81617   249   250   251
0.002 0.430 0.044 0.002 0.002 0.002 0.002 0.123 0.002 0.002 0.002
 252   253   254   255   256   257   258   259   260   261   262
1.033 0.529 1.264 0.611 0.002 0.513 0.085 0.002 0.705 0.840 0.719
 263   264   265   266   267   268   269   270   271   272   273
1.489 0.532 0.150 0.134 0.002 0.002 0.002 0.002 0.002 0.055 0.135
 274   275   276   277   278   279   280   281   282   283   284
0.009 0.002 0.002 0.002 0.008 0.454 1.676 1.462 0.071 0.002 1.029
 285   286   287   288   289   418   419   420   421   422   700
0.055 0.384 0.947 0.002 0.002 0.008 0.759 0.066 0.009 0.002 0.002

--
So far, this is working great.
Now, make a copy of d:
 > dnew <- d

And then fill in the NA values in P01 with the values in r

For example:
 > for (i in 1:length(r)){
   dnew$P01[r[i,1]] <- r[i,2]
   }
This doesn't work, because each 'piece' of r is two numbers:
 > r[1]
  2
0.002
 > r[1,1]
Error in r[1, 1] : incorrect number of dimensions

My question: how can I separate the the two items in (for example)
r[1] to use the first part as an index and the second as a value,
and then use them to replace the NA values with the imputed values?

Or is there a better way to replace the NA values with the imputed 
values?


Thanks in advance for any help.



You didn't state your goal, and why fit.mult.impute does not do what 
you want.   But you can look inside fit.mult.impute to see how it 
retrieves the imputed values.  Also see the example in documentation 
for transcan in which the command impute(xt, imputation=1) to retrieve 
one of the multiple imputations.


Note that you can say library(Design) (omit the quotes) to access both 
Design and Hmisc.


Frank

Thanks for your help.
My goal is to replace the NA values in the (copy of the) data frame with 
the means of the imputed values (which are now in variable 'r').
fit.mult.impute works fine. I just can't figure out the last step, 
taking the results of fit.mult.impute (which are in variable 'r') and 
replacing the NA values in the (copy of the) data frame.
A simple for loop doesn't work because the items in 'r' don't look like 
a normal vector, as for example r[1] returns

 2
0.002
Is there a command to replace the NA values in the data frame with the 
means of the imputed values?


Thanks,
Charlie



Don't do that, as this would no longer be multiple imputation.  If you 
want single conditional mean imputation use transcan.


Frank


--
Frank E Harrell Jr   Professor and Chair   School of Medicine
 Department of Biostatistics   Vanderbilt University

__
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] multiple imputation with fit.mult.impute in Hmisc - how to replace NA with imputed value?

2008-11-26 Thread Charlie Brush

Frank E Harrell Jr wrote:

Charlie Brush wrote:

I am doing multiple imputation with Hmisc, and
can't figure out how to replace the NA values with
the imputed values.

Here's a general ourline of the process:

 > set.seed(23)
 > library("mice")
 > library("Hmisc")
 > library("Design")
 > d <- read.table("DailyDataRaw_01.txt",header=T)
 > length(d);length(d[,1])
[1] 43
[1] 2666
Do for this data set, there are 43 columns and 2666 rows

Here is a piece of data.frame d:
 > d[1:20,4:6]
 P01  P02  P03
1  0.1 0.16 0.16
2   NA 0.00 0.00
3   NA 0.60 0.04
4   NA 0.15 0.00
5   NA 0.00 0.00
6  0.7 0.00 0.75
7   NA 0.00 0.00
8   NA 0.00 0.00
9  0.0 0.00 0.00
10 0.0 0.00 0.00
11 0.0 0.00 0.00
12 0.0 0.00 0.00
13 0.0 0.00 0.00
14 0.0 0.00 0.00
15 0.0 0.00 0.03
16  NA 0.00 0.00
17  NA 0.01 0.00
18 0.0 0.00 0.00
19 0.0 0.00 0.00
20 0.0 0.00 0.00

These are daily precipitation values at NCDC stations, and
NA values at station P01 will be filled using multiple
imputation and data from highly correlated stations P02 and P08:

 > f <- aregImpute(~ I(P01) + I(P02) + I(P08), 
n.impute=10,match='closest',data=d)

Iteration 13
 > fmi <- fit.mult.impute( P01 ~ P02 + P08 , ols, f, d)

Variance Inflation Factors Due to Imputation:

Intercept   P02   P08
   1.01  1.39  1.16

Rate of Missing Information:

Intercept   P02   P08
   0.01  0.28  0.14

d.f. for t-distribution for Tests of Single Coefficients:

Intercept   P02   P08
242291.18116.05454.95
 > r <- apply(f$imputed$P01,1,mean)
 > r
   2 3 4 5 7 81617   249   250   251
0.002 0.430 0.044 0.002 0.002 0.002 0.002 0.123 0.002 0.002 0.002
 252   253   254   255   256   257   258   259   260   261   262
1.033 0.529 1.264 0.611 0.002 0.513 0.085 0.002 0.705 0.840 0.719
 263   264   265   266   267   268   269   270   271   272   273
1.489 0.532 0.150 0.134 0.002 0.002 0.002 0.002 0.002 0.055 0.135
 274   275   276   277   278   279   280   281   282   283   284
0.009 0.002 0.002 0.002 0.008 0.454 1.676 1.462 0.071 0.002 1.029
 285   286   287   288   289   418   419   420   421   422   700
0.055 0.384 0.947 0.002 0.002 0.008 0.759 0.066 0.009 0.002 0.002

--
So far, this is working great.
Now, make a copy of d:
 > dnew <- d

And then fill in the NA values in P01 with the values in r

For example:
 > for (i in 1:length(r)){
   dnew$P01[r[i,1]] <- r[i,2]
   }
This doesn't work, because each 'piece' of r is two numbers:
 > r[1]
  2
0.002
 > r[1,1]
Error in r[1, 1] : incorrect number of dimensions

My question: how can I separate the the two items in (for example)
r[1] to use the first part as an index and the second as a value,
and then use them to replace the NA values with the imputed values?

Or is there a better way to replace the NA values with the imputed 
values?


Thanks in advance for any help.



You didn't state your goal, and why fit.mult.impute does not do what 
you want.   But you can look inside fit.mult.impute to see how it 
retrieves the imputed values.  Also see the example in documentation 
for transcan in which the command impute(xt, imputation=1) to retrieve 
one of the multiple imputations.


Note that you can say library(Design) (omit the quotes) to access both 
Design and Hmisc.


Frank

Thanks for your help.
My goal is to replace the NA values in the (copy of the) data frame with 
the means of the imputed values (which are now in variable 'r').
fit.mult.impute works fine. I just can't figure out the last step, 
taking the results of fit.mult.impute (which are in variable 'r') and 
replacing the NA values in the (copy of the) data frame.
A simple for loop doesn't work because the items in 'r' don't look like 
a normal vector, as for example r[1] returns

 2
0.002
Is there a command to replace the NA values in the data frame with the 
means of the imputed values?


Thanks,
Charlie

__
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] multiple imputation with fit.mult.impute in Hmisc - how to replace NA with imputed value?

2008-11-26 Thread Frank E Harrell Jr

Charlie Brush wrote:

I am doing multiple imputation with Hmisc, and
can't figure out how to replace the NA values with
the imputed values.

Here's a general ourline of the process:

 > set.seed(23)
 > library("mice")
 > library("Hmisc")
 > library("Design")
 > d <- read.table("DailyDataRaw_01.txt",header=T)
 > length(d);length(d[,1])
[1] 43
[1] 2666
Do for this data set, there are 43 columns and 2666 rows

Here is a piece of data.frame d:
 > d[1:20,4:6]
 P01  P02  P03
1  0.1 0.16 0.16
2   NA 0.00 0.00
3   NA 0.60 0.04
4   NA 0.15 0.00
5   NA 0.00 0.00
6  0.7 0.00 0.75
7   NA 0.00 0.00
8   NA 0.00 0.00
9  0.0 0.00 0.00
10 0.0 0.00 0.00
11 0.0 0.00 0.00
12 0.0 0.00 0.00
13 0.0 0.00 0.00
14 0.0 0.00 0.00
15 0.0 0.00 0.03
16  NA 0.00 0.00
17  NA 0.01 0.00
18 0.0 0.00 0.00
19 0.0 0.00 0.00
20 0.0 0.00 0.00

These are daily precipitation values at NCDC stations, and
NA values at station P01 will be filled using multiple
imputation and data from highly correlated stations P02 and P08:

 > f <- aregImpute(~ I(P01) + I(P02) + I(P08), 
n.impute=10,match='closest',data=d)

Iteration 13
 > fmi <- fit.mult.impute( P01 ~ P02 + P08 , ols, f, d)

Variance Inflation Factors Due to Imputation:

Intercept   P02   P08
   1.01  1.39  1.16

Rate of Missing Information:

Intercept   P02   P08
   0.01  0.28  0.14

d.f. for t-distribution for Tests of Single Coefficients:

Intercept   P02   P08
242291.18116.05454.95
 > r <- apply(f$imputed$P01,1,mean)
 > r
   2 3 4 5 7 81617   249   250   251
0.002 0.430 0.044 0.002 0.002 0.002 0.002 0.123 0.002 0.002 0.002
 252   253   254   255   256   257   258   259   260   261   262
1.033 0.529 1.264 0.611 0.002 0.513 0.085 0.002 0.705 0.840 0.719
 263   264   265   266   267   268   269   270   271   272   273
1.489 0.532 0.150 0.134 0.002 0.002 0.002 0.002 0.002 0.055 0.135
 274   275   276   277   278   279   280   281   282   283   284
0.009 0.002 0.002 0.002 0.008 0.454 1.676 1.462 0.071 0.002 1.029
 285   286   287   288   289   418   419   420   421   422   700
0.055 0.384 0.947 0.002 0.002 0.008 0.759 0.066 0.009 0.002 0.002

--
So far, this is working great.
Now, make a copy of d:
 > dnew <- d

And then fill in the NA values in P01 with the values in r

For example:
 > for (i in 1:length(r)){
   dnew$P01[r[i,1]] <- r[i,2]
   }
This doesn't work, because each 'piece' of r is two numbers:
 > r[1]
  2
0.002
 > r[1,1]
Error in r[1, 1] : incorrect number of dimensions

My question: how can I separate the the two items in (for example)
r[1] to use the first part as an index and the second as a value,
and then use them to replace the NA values with the imputed values?

Or is there a better way to replace the NA values with the imputed values?

Thanks in advance for any help.



You didn't state your goal, and why fit.mult.impute does not do what you 
want.   But you can look inside fit.mult.impute to see how it retrieves 
the imputed values.  Also see the example in documentation for transcan 
in which the command impute(xt, imputation=1) to retrieve one of the 
multiple imputations.


Note that you can say library(Design) (omit the quotes) to access both 
Design and Hmisc.


Frank
--
Frank E Harrell Jr   Professor and Chair   School of Medicine
 Department of Biostatistics   Vanderbilt University

__
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] multiple imputation with fit.mult.impute in Hmisc - how to replace NA with imputed value?

2008-11-26 Thread Charlie Brush

I am doing multiple imputation with Hmisc, and
can't figure out how to replace the NA values with
the imputed values.

Here's a general ourline of the process:

> set.seed(23)
> library("mice")
> library("Hmisc")
> library("Design")
> d <- read.table("DailyDataRaw_01.txt",header=T)
> length(d);length(d[,1])
[1] 43
[1] 2666
Do for this data set, there are 43 columns and 2666 rows

Here is a piece of data.frame d:
> d[1:20,4:6]
 P01  P02  P03
1  0.1 0.16 0.16
2   NA 0.00 0.00
3   NA 0.60 0.04
4   NA 0.15 0.00
5   NA 0.00 0.00
6  0.7 0.00 0.75
7   NA 0.00 0.00
8   NA 0.00 0.00
9  0.0 0.00 0.00
10 0.0 0.00 0.00
11 0.0 0.00 0.00
12 0.0 0.00 0.00
13 0.0 0.00 0.00
14 0.0 0.00 0.00
15 0.0 0.00 0.03
16  NA 0.00 0.00
17  NA 0.01 0.00
18 0.0 0.00 0.00
19 0.0 0.00 0.00
20 0.0 0.00 0.00

These are daily precipitation values at NCDC stations, and
NA values at station P01 will be filled using multiple
imputation and data from highly correlated stations P02 and P08:

> f <- aregImpute(~ I(P01) + I(P02) + I(P08), 
n.impute=10,match='closest',data=d)

Iteration 13
> fmi <- fit.mult.impute( P01 ~ P02 + P08 , ols, f, d)

Variance Inflation Factors Due to Imputation:

Intercept   P02   P08
   1.01  1.39  1.16

Rate of Missing Information:

Intercept   P02   P08
   0.01  0.28  0.14

d.f. for t-distribution for Tests of Single Coefficients:

Intercept   P02   P08
242291.18116.05454.95
> r <- apply(f$imputed$P01,1,mean)
> r
   2 3 4 5 7 81617   249   250   251
0.002 0.430 0.044 0.002 0.002 0.002 0.002 0.123 0.002 0.002 0.002
 252   253   254   255   256   257   258   259   260   261   262
1.033 0.529 1.264 0.611 0.002 0.513 0.085 0.002 0.705 0.840 0.719
 263   264   265   266   267   268   269   270   271   272   273
1.489 0.532 0.150 0.134 0.002 0.002 0.002 0.002 0.002 0.055 0.135
 274   275   276   277   278   279   280   281   282   283   284
0.009 0.002 0.002 0.002 0.008 0.454 1.676 1.462 0.071 0.002 1.029
 285   286   287   288   289   418   419   420   421   422   700
0.055 0.384 0.947 0.002 0.002 0.008 0.759 0.066 0.009 0.002 0.002

--
So far, this is working great.
Now, make a copy of d:
> dnew <- d

And then fill in the NA values in P01 with the values in r

For example:
> for (i in 1:length(r)){
   dnew$P01[r[i,1]] <- r[i,2]
   }
This doesn't work, because each 'piece' of r is two numbers:
> r[1]
  2
0.002
> r[1,1]
Error in r[1, 1] : incorrect number of dimensions

My question: how can I separate the the two items in (for example)
r[1] to use the first part as an index and the second as a value,
and then use them to replace the NA values with the imputed values?

Or is there a better way to replace the NA values with the imputed values?

Thanks in advance for any help.

__
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.