Weird change in behavior of summary() function

Follow-up:

I find that the problem does not occur on a Linux system, so it is 
either Mac-specific or some function of the libraries loaded on the 
problem machine.

J.

On 12/14/20 12:24, John Helly wrote:

Aloha.

I have been using the summary function (i.e., summary()) for years 
and, in the last few weeks, suddenly find it behaving in an obviously 
erroneous way.? I expect the DAUCO summary to be summary of the 
character variable but it has these weird NULL:00125 values listed 
for whatever the number of rows is.

It's not limited to this input data so I don't believe that it is 
data-dependent at this point.

This just started happening a number of weeks ago.? I've done some 
updates of the OS and apps since then and re-installed R from the Mac 
*.dmg distro.

I have provided details below and my main questions are 1) has anyone 
else seen this (I can't find any reports of it) and 2) how might I 
debug this?

Thank you.

================ Input data sample (first few records from a flat 
ASCII csv file) ================

DAUCO,Longitude,Latitude,Precipitation,Year,Month
00125,-121.416666667,41.9583333334,63.1469993591,1895,1
00125,-121.375,41.9583333334,63.6969985962,1895,1
00125,-121.333333333,41.9583333334,65.7460021973,1895,1
00125,-121.291666667,41.9583333334,69.4150009155,1895,1
00125,-121.25,41.9583333334,74.0780029297,1895,1

================ R commands and output 
=============================================
PRISM??????? = read.table(PRISM_INPUT,header=TRUE, sep=',',
colClasses=c('character','numeric','numeric','numeric','numeric','numeric')) 

summary(PRISM)

? DAUCO???????? Longitude???????? Latitude Precipitation 
Year????????? Month
?NULL:00125?? Min.?? :-121.4?? Min.?? :41.54?? Min.?? :? 0.00 Min.?? 
:1895?? Min.?? : 1.000
?NULL:00125?? 1st Qu.:-121.2?? 1st Qu.:41.71?? 1st Qu.: 10.65 1st 
Qu.:1926?? 1st Qu.: 3.000
?NULL:00125?? Median :-121.0?? Median :41.79?? Median : 24.41 Median 
:1957?? Median : 6.000
?NULL:00125?? Mean?? :-121.0?? Mean?? :41.79?? Mean?? : 31.09 Mean?? 
:1957?? Mean?? : 6.488
?NULL:00125?? 3rd Qu.:-120.9?? 3rd Qu.:41.88?? 3rd Qu.: 43.73 3rd 
Qu.:1989?? 3rd Qu.: 9.000
?NULL:00125?? Max.?? :-120.6?? Max.?? :41.96?? Max.?? :265.08 Max.?? 
:2020?? Max.?? :12.000
?NULL:00125
?NULL:00125

dput(head(PRISM))

structure(list(DAUCO = c("00125", "00125", "00125", "00125",
"00125", "00125"), Longitude = c(-121.416666667, -121.375, 
-121.333333333,
-121.291666667, -121.25, -121.208333333), Latitude = c(41.9583333334,
41.9583333334, 41.9583333334, 41.9583333334, 41.9583333334, 
41.9583333334
), Precipitation = c(63.1469993591, 63.6969985962, 65.7460021973,
69.4150009155, 74.0780029297, 80.4290008545), Year = c(1895,
1895, 1895, 1895, 1895, 1895), Month = c(1, 1, 1, 1, 1, 1)), 
row.names = c(NA,
6L), class = "data.frame")

sessionInfo()

R version 4.0.3 (2020-10-10)
Platform: x86_64-apple-darwin17.0 (64-bit)
Running under: macOS Catalina 10.15.7

Matrix products: default
BLAS: 
/Library/Frameworks/R.framework/Versions/4.0/Resources/lib/libRblas.dylib
LAPACK: 
/Library/Frameworks/R.framework/Versions/4.0/Resources/lib/libRlapack.dylib

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats???? graphics? grDevices utils???? datasets? methods base

other attached packages:
[1] reshape_0.8.8 plyr_1.8.6??? ggplot2_3.3.2

loaded via a namespace (and not attached):
?[1] Rcpp_1.0.4.6????????? pillar_1.4.4 DEoptimR_1.0-8 
compiler_4.0.3??????? RColorBrewer_1.1-2
?[6] iterators_1.0.12????? digest_0.6.25 lifecycle_0.2.0 
tibble_3.0.1????????? gtable_0.3.0
[11] nlme_3.1-149????????? lattice_0.20-41 pkgconfig_2.0.3 
rlang_0.4.6?????????? foreach_1.5.0
[16] Matrix_1.2-18???????? parallel_4.0.3 ergm_3.10.4 
coda_0.19-3?????????? withr_2.2.0
[21] dplyr_1.0.0?????????? generics_0.0.2 vctrs_0.3.1 
networkDynamic_0.10.1 trust_0.1-8
[26] grid_4.0.3??????????? tidyselect_1.1.0 deSolve_1.28 
robustbase_0.93-6???? glue_1.4.1
[31] R6_2.4.1????????????? farver_2.0.3 purrr_0.3.4 
magrittr_1.5????????? codetools_0.2-16
[36] scales_1.1.1????????? ellipsis_0.3.1 MASS_7.3-53 
lpSolve_5.6.15??????? colorspace_1.4-1
[41] ape_5.4?????????????? labeling_0.3 network_1.16.0 
lazyeval_0.2.2??????? doParallel_1.0.15
[46] EpiModel_1.8.0??????? munsell_0.5.0 tergm_3.6.1 
statnet.common_4.3.0? crayon_1.3.4