[R] lm fails on some large input

[Dingyuan Wang]

I just want to make a line out of timestamps vs some coordinates, so y~x 
or x~y doesn't matter.

Yes, I know the answer. When trying R, I'm surprised that R can't solve 
that either. I first noticed that PostgreSQL can't solve it, and found 
that they fixed that in pg 12.

https://www.postgresql.org/message-id/153313051300.1397.9594490737341194671%40wrigleys.postgresql.org

Therefore I come to ask whether someone know how to fix this in R, or I 
must submit it as a bug?

2019/4/18 23:24, Michael Dewey:
> Perhaps subtract 1506705766 from y?
> 
> Saying some other software does it well implies you know what the 
> _correct_ answer is here but I would question what that means with this 
> sort of data-set.
> 
> On 17/04/2019 07:26, Dingyuan Wang wrote:
>> Hi,
>>
>> This input doesn't have any interesting properties except y is unix 
>> time. Spreadsheets can do this well.
>> Is this a bug that lm can't do x ~ y?
>>
>> R version 3.5.2 (2018-12-20) -- "Eggshell Igloo"
>> Copyright (C) 2018 The R Foundation for Statistical Computing
>> Platform: x86_64-pc-linux-gnu (64-bit)
>>
>>  > x = c(79.744, 123.904, 87.29601, 116.352, 67.71201, 72.96001, 
>> 101.632, 108.928, 94.08)
>>  > y = c(1506705739.385, 1506705766.895, 1506705746.293, 
>> 1506705761.873, 1506705734.743, 1506705735.351, 1506705756.26, 
>> 1506705761.307, 1506705747.372)
>>  > m = lm(x ~ y)
>>  > summary(m)
>>
>> Call:
>> lm(formula = x ~ y)
>>
>> Residuals:
>>       Min       1Q   Median       3Q      Max
>> -27.0222 -14.9902  -0.6542  14.1938  29.1698
>>
>> Coefficients: (1 not defined because of singularities)
>>              Estimate Std. Error t value Pr(>|t|)
>> (Intercept)   94.734      6.511   14.55 4.88e-07 ***
>> y                 NA         NA      NA       NA
>> ---
>> Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
>>
>> Residual standard error: 19.53 on 8 degrees of freedom
>>
>>  > summary(lm(y ~ x))
>>
>> Call:
>> lm(formula = y ~ x)
>>
>> Residuals:
>>      Min      1Q  Median      3Q     Max
>> -2.1687 -1.3345 -0.9466  1.3826  2.6551
>>
>> Coefficients:
>>               Estimate Std. Error   t value Pr(>|t|)
>> (Intercept) 1.507e+09  3.294e+00 4.574e+08  < 2e-16 ***
>> x           6.136e-01  3.413e-02 1.798e+01 4.07e-07 ***
>> ---
>> Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
>>
>> Residual standard error: 1.885 on 7 degrees of freedom
>> Multiple R-squared:  0.9788,    Adjusted R-squared:  0.9758
>> F-statistic: 323.3 on 1 and 7 DF,  p-value: 4.068e-07
>>
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>