# [R] Monte Carlo on simple regression

Ogbos Okike giftedlife2014 @ending from gm@il@com
Wed Aug 22 17:02:59 CEST 2018

```Kind R-users,
I run a simple regression. I am interested in using the Monte Carlo to test
the slope parameter.
Here is what I have done:
Li<-d1\$a
CR<-d2\$a

fit<-lm(Li~CR)
a<-summary(fit)
a gives the slope as 88.15

Problem: I now what to repeat the samples to access this coefficient.
Following one of the related examples I got online, I did (tried to modify):

N <- nrow(Li) # returns the number of observations in the dataset
C <- 50         # desired number of subsamples
S <- 38         # desired sample size

sumb2 <- 0
for (i in 1:C){   # a loop over the number of subsamples
set.seed(3*i)   # a different seed for each subsample
subsample <- Li[sample(1:N, size=S, replace=TRUE), ]
mod <- lm(Li~CR,data=subsample)
#sum b2 for all subsamples:
sumb2 <- sumb2 + coef(mod)[[2]]
}
print(sumb2/C, digits = 3)

But when I run the script, I had error message:
Error in 1:N : argument of length 0
My data:
Li        CR
74281 8449
92473 8148
62310 8520
71219 8264
33469 8389
75768 7499
61636 7821
103829 8468
87336 8568
129443 8190
97682 8539
106918 8502
97171 8578
48012 8181
93086 8631
92374 8562
113010 8404
66956 8592
133037 8632
108849 8644
81544 8442
105072 8615
143437 7724
153294 7829
123735 8682
154738 8756
100760 8839
108034 8839
81826 8858
116901 8847
80780 8869
122684 8736
141716 9087
144315 9166
162078 9147
163184 9267
150688 9275
200848 9259
221570 8943
192424 8564
173024 9282
197326 9318
209344 9293
220201 9242
212626 9324
218115 9319
170001 9314
187490 9346
172440 9350
180330 9349
200807 9355
234994 9350
139053 9284
150048 9361
203650 9346
233331 9369
198790 9340
164060 9382
198000 9401
201707 9355
179257 9369
188736 9298
243392 9393
246040 9374
269058 9364
201657 9370
187942 9354
228514 9305
234000 9392
224431 9395
163502 9398
I would be most glad for your great assistance.
Many thanks.
Ogbos

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