[R] Passing formula as parameter to `lm` within `sapply` causes error [BUG?]

[Jens Heumann]

Thanks a lot for your hint, David. It finally worked doing:

 > sapply(unique(data[[st]]), function(s)
+   summary(do.call("lm", list(FO, data, data[[st]] == s,
+                              data[[ws]])))$coef[1, ])
                 [,1]       [,2]         [,3]
Estimate   1.6269038 -0.1404174 -0.010338774
Std. Error 0.9042738  0.4577001  1.858138516
t value    1.7991275 -0.3067890 -0.005564049
Pr(>|t|)   0.3229600  0.8104951  0.996457853

Best,
Jens

On 30.04.2019 23:03, David Winsemius wrote:
> Try using do.call
> 
> —
> David
> 
> Sent from my iPhone
> 
>> On Apr 30, 2019, at 9:24 AM, Jens Heumann <jens.heumann using students.unibe.ch> wrote:
>>
>> Hi,
>>
>> `lm` won't take formula as a parameter when it is within a `sapply`; see example below. Please, could anyone either point me to a syntax error or confirm that this might be a bug?
>>
>> Best,
>> Jens
>>
>> [Disclaimer: This is my first post here, following advice of how to proceed with possible bugs from here: https://www.r-project.org/bugs.html]
>>
>>
>> SUMMARY
>>
>> While `lm` alone accepts formula parameter `FO` well, the same within a `sapply` causes an error. When putting everything as parameter but formula `FO`, it's still working, though. All parameters work fine within a similar `for` loop.
>>
>>
>> MCVE (see data / R-version at bottom)
>>
>>> summary(lm(y ~ x, df1, df1[["z"]] == 1, df1[["w"]]))$coef[1, ]
>>   Estimate Std. Error    t value   Pr(>|t|)
>> 1.6269038  0.9042738  1.7991275  0.3229600
>>> summary(lm(FO, data, data[[st]] == st1, data[[ws]]))$coef[1, ]
>>   Estimate Std. Error    t value   Pr(>|t|)
>> 1.6269038  0.9042738  1.7991275  0.3229600
>>> sapply(unique(df1$z), function(s)
>> +   summary(lm(y ~ x, df1, df1[["z"]] == s, df1[[ws]]))$coef[1, ])
>>                 [,1]       [,2]         [,3]
>> Estimate   1.6269038 -0.1404174 -0.010338774
>> Std. Error 0.9042738  0.4577001  1.858138516
>> t value    1.7991275 -0.3067890 -0.005564049
>> Pr(>|t|)   0.3229600  0.8104951  0.996457853
>>> sapply(unique(data[[st]]), function(s)
>> +   summary(lm(FO, data, data[[st]] == s, data[[ws]]))$coef[1, ])  # !!!
>> Error in eval(substitute(subset), data, env) : object 's' not found
>>> sapply(unique(data[[st]]), function(s)
>> +   summary(lm(y ~ x, data, data[[st]] == s, data[[ws]]))$coef[1, ])
>>                 [,1]       [,2]         [,3]
>> Estimate   1.6269038 -0.1404174 -0.010338774
>> Std. Error 0.9042738  0.4577001  1.858138516
>> t value    1.7991275 -0.3067890 -0.005564049
>> Pr(>|t|)   0.3229600  0.8104951  0.996457853
>>> m <- matrix(NA, 4, length(unique(data[[st]])))
>>> for (s in unique(data[[st]])) {
>> +   m[, s] <- summary(lm(FO, data, data[[st]] == s, data[[ws]]))$coef[1, ]
>> + }
>>> m
>>           [,1]       [,2]         [,3]
>> [1,] 1.6269038 -0.1404174 -0.010338774
>> [2,] 0.9042738  0.4577001  1.858138516
>> [3,] 1.7991275 -0.3067890 -0.005564049
>> [4,] 0.3229600  0.8104951  0.996457853
>>
>> # DATA #################################################################
>>
>> df1 <- structure(list(x = c(1.37095844714667, -0.564698171396089, 0.363128411337339,
>> 0.63286260496104, 0.404268323140999, -0.106124516091484, 1.51152199743894,
>> -0.0946590384130976, 2.01842371387704), y = c(1.30824434809425,
>> 0.740171482827397, 2.64977380403845, -0.755998096151299, 0.125479556323628,
>> -0.239445852485142, 2.14747239550901, -0.37891195982917, -0.638031707027734
>> ), z = c(1L, 1L, 1L, 2L, 2L, 2L, 3L, 3L, 3L), w = c(0.7, 0.8,
>> 1.2, 0.9, 1.3, 1.2, 0.8, 1, 1)), class = "data.frame", row.names = c(NA,
>> -9L))
>>
>> FO <- y ~ x; data <- df1; st <- "z"; ws <- "w"; st1 <- 1
>>
>> ########################################################################
>>
>>> R.version
>>                _
>> platform       x86_64-w64-mingw32
>> arch           x86_64
>> os             mingw32
>> system         x86_64, mingw32
>> status
>> major          3
>> minor          6.0
>> year           2019
>> month          04
>> day            26
>> svn rev        76424
>> language       R
>> version.string R version 3.6.0 (2019-04-26)
>> nickname       Planting of a Tree
>>
>> #########################################################################
>>
>> NOTE: Question on SO two days ago (https://stackoverflow.com/questions/55893189/passing-formula-as-parameter-to-lm-within-sapply-causes-error-bug-confirmation) brought many views but neither answer nor bug confirmation.
>>
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