R help - Jan 2015 - Getting column names in the titles of histograms generated automatically

I am trying to automatically produce a series of histograms from every column of
data frame with many columns.
The columns names of a shortened from of the data frame follow:


colnames<-names(smdata)
colnames
[1] "X13594_pre" "X15568_pre"


I want to have 
X13594_pre in the title of the first histogram and 
X15568_pre in the title of the second histogram.


I use the following code to automatically generate my histograms:


for (i in 1:2){hist(smdata[,colnames[i]])}


The titles of the histograms produced are:
Histogram of smdata[,colnames[i]]
and
Histogram of smdata[,colnames[i]]


How can I get the titles 
Histogram of smdata[,X13594_pre]
and
Histogram of smdata[,X15568_pre]


John David Sorkin M.D., Ph.D.
Professor of Medicine
Chief, Biostatistics and Informatics
University of Maryland School of Medicine Division of Gerontology and Geriatric
Medicine
Baltimore VA Medical Center
10 North Greene Street
GRECC (BT/18/GR)
Baltimore, MD 21201-1524
(Phone) 410-605-7119
(Fax) 410-605-7913 (Please call phone number above prior to faxing) 


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tmp <- data.frame(a=rnorm(10), b=rnorm(10))
for (i in names(tmp)) hist(tmp[[i]], main=paste("histogram of", i))


On Wed, Jan 7, 2015 at 10:13 PM, John Sorkin
<JSorkin at grecc.umaryland.edu> wrote:
> I am trying to automatically produce a series of histograms from every
column of data frame with many columns.
> The columns names of a shortened from of the data frame follow:
>
>
> colnames<-names(smdata)
> colnames
> [1] "X13594_pre" "X15568_pre"
>
>
> I want to have
> X13594_pre in the title of the first histogram and
> X15568_pre in the title of the second histogram.
>
>
> I use the following code to automatically generate my histograms:
>
>
> for (i in 1:2){hist(smdata[,colnames[i]])}
>
>
> The titles of the histograms produced are:
> Histogram of smdata[,colnames[i]]
> and
> Histogram of smdata[,colnames[i]]
>
>
> How can I get the titles
> Histogram of smdata[,X13594_pre]
> and
> Histogram of smdata[,X15568_pre]
>
>
> John David Sorkin M.D., Ph.D.
> Professor of Medicine
> Chief, Biostatistics and Informatics
> University of Maryland School of Medicine Division of Gerontology and
Geriatric Medicine
> Baltimore VA Medical Center
> 10 North Greene Street
> GRECC (BT/18/GR)
> Baltimore, MD 21201-1524
> (Phone) 410-605-7119
> (Fax) 410-605-7913 (Please call phone number above prior to faxing)
>
>
> Confidentiality Statement:
> This email message, including any attachments, is for ...{{dropped:12}}

Richard,
WOW! A totally new way to think about loop indices, many, many, thanks!John



John David Sorkin M.D., Ph.D.
Professor of Medicine
Chief, Biostatistics and Informatics
University of Maryland School of Medicine Division of Gerontology and Geriatric
Medicine
Baltimore VA Medical Center
10 North Greene Street
GRECC (BT/18/GR)
Baltimore, MD 21201-1524
(Phone) 410-605-7119
(Fax) 410-605-7913 (Please call phone number above prior to faxing) 
>>> "Richard M. Heiberger" <rmh at temple.edu> 01/07/15
10:27 PM >>>
tmp <- data.frame(a=rnorm(10), b=rnorm(10))
for (i in names(tmp)) hist(tmp[[i]], main=paste("histogram of", i))


On Wed, Jan 7, 2015 at 10:13 PM, John Sorkin
<JSorkin at grecc.umaryland.edu> wrote:
> I am trying to automatically produce a series of histograms from every
column of data frame with many columns.
> The columns names of a shortened from of the data frame follow:
>
>
> colnames<-names(smdata)
> colnames
> [1] "X13594_pre" "X15568_pre"
>
>
> I want to have
> X13594_pre in the title of the first histogram and
> X15568_pre in the title of the second histogram.
>
>
> I use the following code to automatically generate my histograms:
>
>
> for (i in 1:2){hist(smdata[,colnames[i]])}
>
>
> The titles of the histograms produced are:
> Histogram of smdata[,colnames[i]]
> and
> Histogram of smdata[,colnames[i]]
>
>
> How can I get the titles
> Histogram of smdata[,X13594_pre]
> and
> Histogram of smdata[,X15568_pre]
>
>
> John David Sorkin M.D., Ph.D.
> Professor of Medicine
> Chief, Biostatistics and Informatics
> University of Maryland School of Medicine Division of Gerontology and
Geriatric Medicine
> Baltimore VA Medical Center
> 10 North Greene Street
> GRECC (BT/18/GR)
> Baltimore, MD 21201-1524
> (Phone) 410-605-7119
> (Fax) 410-605-7913 (Please call phone number above prior to faxing)
>
>
> Confidentiality Statement:
> This email message, including any attachments, is for the sole use of the
intended recipient(s) and may contain confidential and privileged information.
Any unauthorized use, disclosure or distribution is prohibited. If you are not
the intended recipient, please contact the sender by reply email and destroy all
copies of the original message.
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> PLEASE do read the posting guide
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Confidentiality Statement:
This email message, including any attachments, is for the sole use of the
intended recipient(s) and may contain confidential and privileged information.
Any unauthorized use, disclosure or distribution is prohibited. If you are not
the intended recipient, please contact the sender by reply email and destroy all
copies of the original message.