The following works nicely. Thank you. plot(z, sf[[s]], type="l") #where the dataframe name in my case is "sf" Sorry - I meant to say there were 24 rows in each column, so z=1:24 Gregory A. Graves, Lead Scientist Everglades REstoration COoordination and VERification (RECOVER) Restoration Sciences Department South Florida Water Management District Phones:? DESK: 561 / 682 - 2429 ?????????? ?? CELL:? 561 / 719 - 8157 -----Original Message----- From: David Winsemius [mailto:dwinsemius at comcast.net] Sent: Tuesday, November 30, 2010 11:50 AM To: Graves, Gregory Cc: r-help at r-project.org Subject: Re: [R] reference text variables as column name to plot
On Nov 30, 2010, at 11:40 AM, Graves, Gregory wrote:
Having given myself carpal tunnel looking for answer to this ... I have a dataset
Named.... what?
each column of which has 12 rows in it. I created a variable 'z' as follows: z=1:24 s
Why did you put twice as many elements in z as there are in a column?
Since I have a large number of these plots to make, and they are a bit
complex, I want to want to reference the column I want to plot via a
variable containing the name of that column. As follows:
similar='1978'
s=paste('Y',similar,sep='')
variable s now contains 'Y1978' which is the name of one of the
columns.
However, when I try to plot
plot(z,s,type='l')
Try this ... assuming that there really are 12 item length columns in a dataframe named, dfm. plot(1:12, dfm[[s]], type="l") dataframes are lists that can be accessed by the names of columns which are interpreted. Don't assume that you can get such interpretation with the $ operator.
I get a 'x and y lengths differ' error because variable s is being recognized as 'Y1978' length=1, rather than the contents of the column Y1978 length=12. I tried all the usual tricks I know like &s.
Huh? "&" is a logical operator.
How do you get R to
reference a variable as a column name?
Thank you.
Gregory A. Graves, Lead Scientist
Everglades REstoration COoordination and VERification (RECOVER)
Restoration Sciences Department
South Florida Water Management District
Phones: DESK: 561 / 682 - 2429
CELL: 561 / 719 - 8157
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David Winsemius, MD West Hartford, CT