[R] error in creating gantt chart.

[David Winsemius]

On Aug 24, 2009, at 8:22 AM, rajclinasia wrote:

>
> hi every one,
> i have a excel sheet like this
>
>       labels   starts     ends
> 1  first task 1-Jan-04 3-Mar-04
> 2 second task 2-Feb-04 5-May-04
> 3  third task 3-Mar-04 6-Jun-04
> 4 fourth task 4-Apr-04 8-Aug-04
> 5  fifth task 5-May-04 9-Sep-04
>
> now i converted this excel sheet into csv file and i read the csv  
> file into
> R with the below code.
>
> my.gantt.info<-read.csv("C:/Documents and
> Settings/balakrishna/Desktop/one.csv").

 > my.gantt.info<-read.csv(textConnection("      labels   starts      
ends
+ 1  first task 1-Jan-04 3-Mar-04
+ 2 second task 2-Feb-04 5-May-04
+ 3  third task 3-Mar-04 6-Jun-04
+ 4 fourth task 4-Apr-04 8-Aug-04
+ 5  fifth task 5-May-04 9-Sep-04"))
 > my.gantt.info
          labels...starts.....ends
1 1  first task 1-Jan-04 3-Mar-04
2 2 second task 2-Feb-04 5-May-04
3 3  third task 3-Mar-04 6-Jun-04
4 4 fourth task 4-Apr-04 8-Aug-04
5 5  fifth task 5-May-04 9-Sep-04

So that may look successful to you but that data.frame contains all of  
that data in a single (character) column. Why? Because a function was  
expecting commas on a file that did not have any. You will probably  
get further along if you use read.table with header=TRUE. Maybe you  
did something different or the file did have commas. With such a small  
file, you really should present the results of

dput(my.gantt.info)

That will contain all the values and attributes of the R object  ...  
no more guessing, which is what we are doing now.
>
> and for create gantt chart i used below code.
>
> gantt.chart("my.gantt.info").

That looks wrong. my.gantt.info is an R object. Is gantt.chart (from  
whatever unspecified package) really expecting to have its arguments  
quoted? I would bet against that possibility.

I would also guess that, even if the data input issues are not a  
problem and the quotes are removed, you still have not converted those  
character values that you think look like dates into objects that R  
will interpret as dates.

?as.Date

>
> if i run this above code i am getting the error like this
>
> Error in x$starts : $ operator is invalid for atomic vectors.
>
> can anybody help in this aspect it would be very appreciable.
> Thanks in Advance.


David Winsemius, MD
Heritage Laboratories
West Hartford, CT