# [R] Error: invalid type (closure) for the variable 'time' - object specific trend

Tobias Christoph s3tochri at uni-bayreuth.de
Fri May 12 16:40:49 CEST 2017

```Hey guys,

thanks a lot for your tips. The regression is finally running. As you
said, I had to integrate the column "year" in the function "time" in R.

So I used the following formula: *plm(log(revenue) ~ log(supply) +
factor(town)*time(year), data=R_Test_log_Neu)*

So I have now sucessfully added a linear trend to my regression model?
Another question that concernes me is how to add a quadratic trend
instead of a linear trend. Can I just square the column "year"?

Toby

_My results see below:_

Balanced Panel: n=11, T=12, N=132

Residuals :
Min.  1st Qu.   Median  3rd Qu.     Max.
-0.09610 -0.02370 -0.00152  0.01980  0.14000

Coefficients :
Estimate Std. Error t-value  Pr(>|t|)
log(supply)               -0.0080702  0.0133675 -0.6037  0.547411
factor(town)2:time(year)  -0.0063245  0.0053744 -1.1768  0.242100
factor(town)3:time(year)   0.0295522  0.0056776  5.2050 1.053e-06 ***
factor(town)4:time(year)   0.0062191  0.0054152  1.1485  0.253549
factor(town)5:time(year)   0.0159028  0.0054954  2.8939  0.004681 **
factor(town)6:time(year)   0.0237112  0.0055395  4.2804 4.316e-05 ***
factor(town)7:time(year)   0.0410007  0.0055734  7.3565 5.576e-11 ***
factor(town)8:time(year)   0.0239085  0.0053751  4.4480 2.271e-05 ***
factor(town)9:time(year)   0.0242342  0.0056855  4.2625 4.619e-05 ***
factor(town)10:time(year)  0.0105890  0.0053302  1.9866  0.049733 *
factor(town)11:time(year)  0.0095270  0.0056354  1.6906  0.094065 .
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

Total Sum of Squares:    0.46388
Residual Sum of Squares: 0.2001
R-Squared:      0.56863
F-statistic: 11.8637 on 11 and 99 DF, p-value: 7.3065e-14

Am 11.05.2017 um 23:17 schrieb David L Carlson:
> What Rui said, but as important, you have four columns in your data called "town", "year", "revenue", and "supply". You do not have a column called "time".
>
> -------------------------------------
> David L Carlson
> Department of Anthropology
> Texas A&M University
> College Station, TX 77840-4352
>
> -----Original Message-----
> From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of Rui Barradas
> Sent: Thursday, May 11, 2017 3:36 PM
> To: Tobias Christoph <s3tochri at uni-bayreuth.de>; Duncan Murdoch <murdoch.duncan at gmail.com>; r-help at r-project.org
> Subject: Re: [R] Error: invalid type (closure) for the variable 'time' - object specific trend
>
> Hello,
>
> A closure is, like you say, a function.
> At an R prompt try:
>
>   > typeof(time)
> [1] "closure"
>
> So like Duncan suggested rename 'time', for instance capitalize it
> 'Time'. That should do it.
>
> Hope this helps,
>
>
>
>
> Em 11-05-2017 21:20, Tobias Christoph escreveu:
>> Hey Duncan,
>>
>>
>> _My data used:_
>>
>> 1st column(town):1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,...........,11
>>
>> 2nd column(year):1,2,3,4,5,6,7,8,9,10,11,12,1,2,3.......,12
>>
>> 3rd column (revenue):
>>
>> 4th colum (supply):
>>
>> I have now renamed my colums and did the regression again. Now there is
>> a problem with R-squared, as it is the sum of 1 now with no given std.
>> error and t-value. This is probably due to the fact, that I try to
>> estimate more parameters than data.
>>
>> To add a linear trend I found the following formular:*lm(y ~ x1 +
>> factor(ccode)*time, data=df)*
>>
>> I try to I decode it for and use it for my regression: *plm(log(revenue)
>> ~ log(supply) + factor(town)*time, data=R_Test_log_Neu)*
>>
>> When I do this regression I will get the original error: "invalid type
>> (closure) for the variable 'time' - object specific trend"
>>
>> With the notation"time" not my colum is meant, but probably the command
>> "time" in R.
>>
>> Can you follow my thoughts?
>>
>> Tobi
>>
>>
>>
>>
>>
>>
>> Am 11.05.2017 um 17:23 schrieb Duncan Murdoch:
>>> Duncan Murdoch
>> ______________________________________________
>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
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