library(dplyr)
## 
## Attaching package: 'dplyr'
## The following objects are masked from 'package:stats':
## 
##     filter, lag
## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union
library(ggplot2)

working directory

First, set up your working directory where you have your data file and working R file.

setwd("/Users/se776257/OneDrive - University of Central Florida/Desktop/Prof. An/02 Teaching/2024 Spring/PAD 7754 Quantitative Methods/R script/")

Import data from your working folder.

db <- read.csv("2022_HIC.csv", stringsAsFactors = F)

If you want to only select cases in Florida

df <- db %>%
  filter(CocState == "FL")

df <- df %>%
  filter(!is.na(PIT.Count))

Scatterplots

You want to examine the relationship between PIT count (# of sheltered people) and # of beds

summary(df$PIT.Count)
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##    0.00    7.00   16.00   32.82   36.00  850.00
summary(df$Total.Beds)
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##    0.00   10.00   20.00   39.69   44.00 1010.00
ggplot(data = df) + 
  geom_point(mapping = aes(x = PIT.Count, y = Total.Beds))

Let’s add a regression line

correlation

From the scatterplots, we suspect there is a significant linear relationship between the two variables. Now we want to calcaulte the correlation

cor(df$PIT.Count, df$Total.Beds)
## [1] 0.9640077

You will notice that when running a cor function with a variable that includes missing data which is very common, the result will appear as “NA.” To correct that, add the following option.

cor(df$PIT.Count, df$Total.Beds, use ="complete.obs")
## [1] 0.9640077

Least Squares Regression

Let’s call our fitted model model1. Then we have:

model1=lm(data=df, formula= Total.Beds ~ PIT.Count)

summary(model1)
## 
## Call:
## lm(formula = Total.Beds ~ PIT.Count, data = df)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -84.144  -5.604  -4.230   0.312 309.260 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept) 3.863633   0.599650   6.443 1.67e-10 ***
## PIT.Count   1.091589   0.008539 127.832  < 2e-16 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 18.7 on 1243 degrees of freedom
## Multiple R-squared:  0.9293, Adjusted R-squared:  0.9293 
## F-statistic: 1.634e+04 on 1 and 1243 DF,  p-value: < 2.2e-16

“lm” stands for linear model, so the first letter is an L. The first line calculates the results of the linear regression.The second line prints the results.

#Residuals and plots of the residuals # We can create the residuals after fitting the model

residuals(model1)
##            1            2            3            4            5            6 
## -10.69540931  -4.13839949   0.31206763  11.28963679   1.20552493  -4.13839949 
##            7            8            9           10           11           12 
##  -4.22998830  -4.50475474  -4.87110999  -4.13839949  -5.42064287  -4.04681067 
##           13           14           15           16           17           18 
##  -3.95522186  -3.95522186  -6.61129745  -4.13839949  -4.32157711  -4.32157711 
##           19           20           21           22           23           24 
##  -5.51223169  17.93075849  -4.41316593   3.94571238  16.83916967  11.76253475 
##           25           26           27           28           29           30 
##  -4.77952118  -3.95522186  -4.50475474  -3.22998830  -6.70288626  -5.32905406 
##           31           32           33           34           35           36 
##  -5.60382050  -7.34400795 -16.59447810  48.56440323  -6.97765270  -5.51223169 
##           37           38           39           40           41           42 
##  -4.50475474  -3.86363305  -4.41316593  -3.95522186  -4.41316593  -5.14587643 
##           43           44           45           46           47           48 
##  -5.60382050  -4.41316593  -4.22998830   6.20552493  20.22047882  -6.15335338 
##           49           50           51           52           53           54 
##  11.49524526  -5.14587643  -4.50475474  -7.61877439  -7.61877439  -5.32905406 
##           55           56           57           58           59           60 
##  -5.32905406  -4.87110999  -4.59634355  -6.42811982 -13.66363608  -4.22998830 
##           61           62           63           64           65           66 
##  -8.16830727  -4.13839949  -4.59634355  -5.42064287  -5.78699813  -4.59634355 
##           67           68           69           70           71           72 
##  -3.95522186  -4.68793237   7.35131782  -4.13839949  -4.68793237  -5.42064287 
##           73           74           75           76           77           78 
##  -7.80195202  -5.51223169  -5.05428762 -12.56457032  -4.15335338  17.95318933 
##           79           80           81           82           83           84 
##  -5.51223169  -9.26737303 -39.94962552  -3.95522186  -4.32157711  -3.95522186 
##           85           86           87           88           89           90 
##  13.78121954  -4.32157711  12.12141306 -46.08607601  -2.80195202   4.77935410 
##           91           92           93           94           95           96 
##  -5.60382050  35.12141306  -3.16083033  -4.59634355 -66.96832546   0.47281442 
##           97           98           99          100          101          102 
##   0.22047882  -2.84681370  -6.06176457  -3.95522186   4.57188018  -5.14587643 
##          103          104          105          106          107          108 
##  -2.04681067  -4.77952118  -5.42064287  -6.70288626  -4.96269881  -6.97765270 
##          109          110          111          112          113          114 
##  61.55692629  -2.78699813  -7.98512965  -5.32905406  -4.77952118  -7.16083033 
##          115          116          117          118          119          120 
##  20.95318933  21.57188018  -4.59634355  -3.95522186  -5.97017575  -4.59634355 
##          121          122          123          124          125          126 
##  -6.15335338  -5.23746525  30.21300187  -4.22998830  -5.42064287   0.11393611 
##          127          128          129          130          131          132 
##  -6.24494219  32.40365645  -5.23746525  -6.88606389  -5.78699813  -4.77952118 
##          133          134          135          136          137          138 
##  -5.05428762  -4.13839949  -5.60382050  -5.51223169  -5.32905406  20.85412357 
##          139          140          141          142          143          144 
##  -4.04681067  -4.68793237  -5.05428762  -4.04681067  -3.22998830  20.40365645 
##          145          146          147          148          149          150 
##  -5.69540931  -4.50475474  -4.13839949  -4.14587643  -6.37952724  -4.59634355 
##          151          152          153          154          155          156 
##  -5.32905406  -5.14587643  -4.32157711  -5.97017575  -3.95522186  28.84664662 
##          157          158          159          160          161          162 
##  31.86160051 108.74758086  -4.13839949  16.29711374   0.12889001  21.86160051 
##          163          164          165          166          167          168 
##   6.62608426 -25.11223775  -5.87858694  -5.24494219  -5.32905406  -4.87110999 
##          169          170          171          172          173          174 
##  -6.79447507 -10.64120524  -6.89354083   1.57188018  -4.32157711  -5.78699813 
##          175          176          177          178          179          180 
##  11.57935713  -2.26737303  -4.13839949  -3.95522186  -5.42064287  -4.41316593 
##          181          182          183          184          185          186 
##  -3.95522186  -1.87110999   5.67094594  -4.32157711   6.22047882  -3.96269881 
##          187          188          189          190          191          192 
##  42.48776831  17.81112733  25.89337375 -10.73279405  -5.05428762  -8.90101778 
##          193          194          195          196          197          198 
##   6.29711374   6.30459069  -7.71036321   3.28963679  -5.14587643  -2.77952118 
##          199          200          201          202          203          204 
##   7.85412357   9.45038358  -4.13839949  -4.68793237  -5.87858694  -5.52718558 
##          205          206          207          208          209          210 
##  -1.88606389  -2.41316593  -2.59634355  -4.87110999  -4.04681067   0.86160051 
##          211          212          213          214          215          216 
##  -4.04681067 -10.42064287 -13.87858694  -3.32157711  -2.59634355  -4.59634355 
##          217          218          219          220          221          222 
##  -4.13839949  -4.22998830  -4.22998830  -4.22998830  -5.23746525  -1.68793237 
##          223          224          225          226          227          228 
## -11.78699813  12.92328154  -5.05428762  -4.50475474  -4.77952118  -3.95522186 
##          229          230          231          232          233          234 
##  -4.96269881  -4.68793237  -2.95522186  -4.13839949  -0.59634355  -3.95522186 
##          235          236          237          238          239          240 
##  -4.96269881 -14.57952421  -3.86363305 -11.37391574  -4.96269881  -4.15335338 
##          241          242          243          244          245          246 
##  -2.68793237  -6.42811982  -1.05428762  50.84851207  -0.96269881   6.29711374 
##          247          248          249          250          251          252 
##   2.49524526   0.84664662 -14.08419541  -5.23746525  -8.71784015  -3.95522186 
##          253          254          255          256          257          258 
##  -4.77952118  -8.44307371  -3.68793237  16.80926188  -3.68793237  -4.13839949 
##          259          260          261          262          263          264 
##  -4.77952118  -6.15335338 -12.10662625  -3.68793237  -4.50475474  -2.42064287 
##          265          266          267          268          269          270 
##  -5.60382050   8.85412357   0.03730119  10.22047882  11.95318933   1.40365645 
##          271          272          273          274          275          276 
##  -4.04681067   0.67842289  -4.22998830  -4.22998830  -4.32157711  -4.32157711 
##          277          278          279          280          281          282 
##   0.95318933  -1.04681067  -4.50475474  -4.32157711  -0.41316593  -4.04681067 
##          283          284          285          286          287          288 
##  -5.05428762  -1.15335338  -5.05428762  -3.41316593  -4.96269881  -5.97017575 
##          289          290          291          292          293          294 
##  -6.33653101  -4.04681067  -3.04681067  -4.77952118  -1.13839949  -2.13839949 
##          295          296          297          298          299          300 
##  -4.04681067  -4.13839949   1.31206763  -1.95522186  -5.23746525   0.86160051 
##          301          302          303          304          305          306 
##  -4.97017575 -10.36643879  -5.23746525  -5.51223169  -2.59634355  -0.22998830 
##          307          308          309          310          311          312 
##   2.31206763  -3.90101778  44.76253475  44.76253475   7.74010391  -5.05428762 
##          313          314          315          316          317          318 
##  -7.61877439  -5.78699813  -5.14587643  -5.05428762  -4.96269881  -5.05428762 
##          319          320          321          322          323          324 
##  -4.68793237  -5.42064287  -5.05428762  -7.25241914  -5.60382050  -3.87858694 
##          325          326          327          328          329          330 
##  -4.87110999  -5.51223169  -6.15335338  -8.53466253  -8.16830727  -5.97017575 
##          331          332          333          334          335          336 
## -17.69354386  -4.50475474  -5.62625134   0.66346899  -4.41316593  -4.41316593 
##          337          338          339          340          341          342 
##  -8.07671846  -2.59634355  -5.23746525  -0.69540931  -6.82438286  -4.96269881 
##          343          344          345          346          347          348 
##  -4.87110999  -3.22998830  -2.87110999  -4.42064287  -1.50475474  -2.87858694 
##          349          350          351          352          353          354 
##  -4.32157711  -1.70288626   7.12889001 -11.92344862 -13.20569201  -6.33653101 
##          355          356          357          358          359          360 
##  -2.51223169  -7.16083033 -13.57204726 -11.65615913  -5.42064287   1.46533747 
##          361          362          363          364          365          366 
##  17.38870255  13.67094594  -1.50475474  -2.91597168  12.48776831   1.02982425 
##          367          368          369          370          371          372 
## 101.10645917  18.49524526  18.86160051  -7.71036321  -5.14587643  -2.51223169 
##          373          374          375          376          377          378 
##  -3.71036321  96.23729816  -7.25241914 126.59617647  42.92328154  -4.71036321 
##          379          380          381          382          383          384 
##  -4.50475474   9.22047882  -4.05428762  -5.51223169  -3.95522186   1.20552493 
##          385          386          387          388          389          390 
##  -1.41316593  -3.79447507  -4.04681067  -6.15335338  -7.52718558  -4.22998830 
##          391          392          393          394          395          396 
##  -5.97017575 -15.67858997  -5.32905406   9.48776831  -7.43559677  -7.52718558 
##          397          398          399          400          401          402 
##  -5.51223169  -2.98512965  -6.15335338  -5.87858694 -24.19634961  -4.87110999 
##          403          404          405          406          407          408 
##  -4.13839949  -6.42811982  -5.87858694  -6.97765270  -6.33653101   5.03730119 
##          409          410          411          412          413          414 
##   9.93075849  -9.81690591 -11.37391574  -9.54213947  -5.32905406  -1.98512965 
##          415          416          417          418          419          420 
##   1.86160051  -5.23746525 -12.74774794  -4.41316593  54.13636695 -14.85429065 
##          421          422          423          424          425          426 
##  -5.32905406  -1.68793237  -5.15335338 -60.55710852  -7.34400795  -4.13839949 
##          427          428          429          430          431          432 
##  -4.68793237   2.31206763   2.67842289  -4.87110999  -4.32157711  -5.51223169 
##          433          434          435          436          437          438 
##  -0.49354690  -6.51970863   5.48776831  26.13636695   5.93823543  -4.68793237 
##          439          440          441          442          443          444 
##  -6.15335338  -6.70288626  21.77001170  -2.96269881  -4.13839949   0.22047882 
##          445          446          447          448          449          450 
##  -1.68793237  -4.41316593  -4.87110999  -5.14587643  -5.23746525  -7.06924151 
##          451          452          453          454          455          456 
##  -4.32157711  -4.68793237  -4.32157711  -4.60382050  -9.55709337  -6.06176457 
##          457          458          459          460          461          462 
##  -6.43559677  -9.54213947  -5.05428762 -15.86176760  -7.34400795  -4.87110999 
##          463          464          465          466          467          468 
##  -7.98512965  -4.77952118  -5.24494219   6.83916967   5.85412357  17.75505781 
##          469          470          471          472          473          474 
##  22.31206763  -2.52718558  -7.18326117   9.39617950  -4.87110999   1.31206763 
##          475          476          477          478          479          480 
##  -5.51223169   5.48029137   4.10645917  -0.22998830  -4.96269881   9.77001170 
##          481          482          483          484          485          486 
##  -3.95522186   3.58683407  -7.98512965  39.38870255   8.02234730  -2.14587643 
##          487          488          489          490          491          492 
##  -5.05428762  -3.96269881  -6.15335338  -7.80195202  -0.22998830  -4.04681067 
##          493          494          495          496          497          498 
##  -4.13839949   9.76253475   0.31206763  -6.71784015  29.01487035   3.76253475 
##          499          500          501          502          503          504 
##  -0.06176457  -2.70288626  -0.25241914  10.11393611  -3.32905406 -43.06364517 
##          505          506          507          508          509          510 
##  -0.68793237   2.12889001   2.95318933   4.22047882  -3.14587643  -1.87110999 
##          511          512          513          514          515          516 
##  -3.05428762  -4.75522489  -8.16830727  -1.13839949  -8.35148490  -0.05428762 
##          517          518          519          520          521          522 
##   6.89337375  19.38870255  -3.88606389  13.57935713  81.20552493  53.02234730 
##          523          524          525          526          527          528 
##   5.57188018  -4.96269881  -7.98512965  -8.99260659  -4.59634355  -3.95522186 
##          529          530          531          532          533          534 
##  -4.59634355   9.46533747  -4.60382050   8.77001170  -4.41316593  -5.23746525 
##          535          536          537          538          539          540 
##  -4.96269881  -9.88606389  -3.87110999  -2.60382050  -1.50475474  -0.95522186 
##          541          542          543          544          545          546 
##  -3.05428762   1.58683407  -2.95522186  -3.44307371  -2.79447507 -11.28232693 
##          547          548          549          550          551          552 
##  -4.35896185  -2.13839949  -3.17578422  -3.88606389  -4.44307371  -1.61129745 
##          553          554          555          556          557          558 
##  -8.05428762  -4.41316593  15.58683407  -6.15335338   5.92328154  -1.95522186 
##          559          560          561          562          563          564 
## -14.18326117  -6.33653101  -4.77952118 -10.18326117  -3.41316593  -3.83185981 
##          565          566          567          568          569          570 
##  -1.13839949   2.67842289  -2.77952118  -5.60382050  -1.04681067  -4.04681067 
##          571          572          573          574          575          576 
##   0.04477814  -6.42811982   0.22047882  -4.04681067  -1.32905406  11.76253475 
##          577          578          579          580          581          582 
## -24.20382656 -22.11971470  -1.04681067  -4.32157711   8.86160051  12.28215985 
##          583          584          585          586          587          588 
##  -4.96269881  -7.35148490  20.59617647   0.46533747  -3.51223169   3.84664662 
##          589          590          591          592          593          594 
##   0.93823543  -8.44307371  -2.60382050  -8.96269881  -7.80195202  -3.32157711 
##          595          596          597          598          599          600 
##  -6.24494219 -10.61877439  -0.70288626  -7.33653101 -11.09914930 -13.42811982 
##          601          602          603          604          605          606 
##   0.86160051   5.02982425  -8.91597168   1.12889001  12.48029137  -6.52718558 
##          607          608          609          610          611          612 
##   1.94571238   1.56440323  -3.72531710  -2.26737303  -0.61129745  -4.25241914 
##          613          614          615          616          617          618 
## -11.55709337  -5.60382050 -18.40382353  11.20552493   8.49524526 117.35504871 
##          619          620          621          622          623          624 
## 101.83355817 -10.82438286 -11.46550456  -7.61877439  16.66346899  -6.42811982 
##          625          626          627          628          629          630 
##  -7.43559677  -7.52718558  -8.07671846  -7.61877439   4.75505781  -6.31971166 
##          631          632          633          634          635          636 
##  -3.86176760  -7.71036321  -2.78699813 -61.79260963  -4.50475474   3.94571238 
##          637          638          639          640          641          642 
##   1.40365645  -2.42064287  -4.22998830  -0.77952118  -3.95522186  -4.50475474 
##          643          644          645          646          647          648 
##   5.04477814  30.74010391  80.32888698  -0.04681067  -5.69540931  11.31206763 
##          649          650          651          652          653          654 
## -28.93840252  11.27468290   0.39617950  -4.50475474   2.64851510 -10.06176457 
##          655          656          657          658          659          660 
## -24.28980388   6.67842289 -14.27673059  -1.15335338   3.46533747   8.40552190 
##          661          662          663          664          665          666 
##  -2.40382353  -4.68793237  -4.22998830  -4.32157711  -4.32157711  -3.32157711 
##          667          668          669          670          671          672 
##  -4.77952118  -3.04681067  -4.87110999  -4.41316593  -6.68606692  15.13636695 
##          673          674          675          676          677          678 
##  -4.97017575   1.38870255  -4.22998830   0.62608426  -2.41316593  -4.05428762 
##          679          680          681          682          683          684 
##  -5.23746525  -3.87110999  -6.33653101  -1.97765270  -5.69540931  -4.97765270 
##          685          686          687          688          689          690 
##   0.22047882   2.40365645  -4.22998830  -4.13839949  -4.13839949 -20.25803064 
##          691          692          693          694          695          696 
##  -8.44307371  -6.06176457  -4.41316593 -10.05428762  -5.42064287  -5.42064287 
##          697          698          699          700          701          702 
##  -2.06924151  -9.45055066  -7.71036321  -6.14587643  -4.50475474   0.49524526 
##          703          704          705          706          707          708 
##  -0.22998830  -2.04681067   2.12889001   0.12889001   1.58683407  10.66533444 
##          709          710          711          712          713          714 
##  -1.14587643  19.73262697   0.22047882  -5.05428762  -2.04681067  -0.04681067 
##          715          716          717          718          719          720 
##   9.13636695  -4.59634355  -3.68793237  -4.59634355  -3.86363305 -10.97017575 
##          721          722          723          724          725          726 
##   9.22047882  25.12141306  -8.44307371  -4.04681067  -0.86363305  -4.42811982 
##          727          728          729          730          731          732 
##  -9.74774794  -0.06924151  18.40365645   9.75505781  15.04477814  -5.51223169 
##          733          734          735          736          737          738 
##  -4.68793237  -4.96269881 -10.09167235  -2.04681067  -4.04681067 -15.71036321 
##          739          740          741          742          743          744 
## -19.16083033   1.21300187  -4.50475474 139.22047882  -3.95522186  36.20552493 
##          745          746          747          748          749          750 
##   2.66346899 -12.19821506  -7.34400795  -5.32905406 -10.91597168  17.22047882 
##          751          752          753          754          755          756 
##  52.57374563   1.44477208  26.13636695  -7.06924151  -7.61877439  -6.24494219 
##          757          758          759          760          761          762 
##  -1.13839949  -2.59634355   8.12889001  -5.05428762   4.12889001  -5.05428762 
##          763          764          765          766          767          768 
##  -6.79447507  -6.33653101  -6.70288626  10.48776831  -4.87110999  -4.04681067 
##          769          770          771          772          773          774 
##  -6.06176457  -6.79447507  -9.63372829  -6.25989609  -4.76270184 -26.68420147 
##          775          776          777          778          779          780 
##  -0.97017575  -2.06924151  -3.97017575  -4.68793237 -19.99260659  -4.53466253 
##          781          782          783          784          785          786 
## -11.06924151  -4.04681067  14.99243951 -56.98326420 -32.35709640  -7.70288626 
##          787          788          789          790          791          792 
##  -0.06176457  -3.95522186  -5.51223169   1.22047882 -29.18326117   2.22047882 
##          793          794          795          796          797          798 
##  27.20552493  -8.25989609  46.85412357 -11.81690591  -9.36643879  -8.25989609 
##          799          800          801          802          803          804 
##  56.69524223 -22.22813801  -4.22998830  -5.97017575  43.77001170  -4.78699813 
##          805          806          807          808          809          810 
##  -6.06176457  19.57935713   2.12889001  -4.22998830  22.85412357  32.48029137 
##          811          812          813          814          815          816 
##   0.85412357  -3.16830727  19.58683407  -9.79447507  -4.59634355  10.04477814 
##          817          818          819          820          821          822 
##  17.40365645  -4.04681067  -5.78699813  -4.77952118  -1.16830727  -4.41316593 
##          823          824          825          826          827          828 
## -10.64120524  -4.22998830  15.02982425   3.94571238  -7.05428762  -5.14587643 
##          829          830          831          832          833          834 
##  -2.68793237   5.95318933  -7.80195202 -12.05428762  -0.35896185   0.02234730 
##          835          836          837          838          839          840 
##  -4.59634355  -5.32905406  -7.35148490  -8.87858694 -17.41877742 -84.14401098 
##          841          842          843          844          845          846 
## -17.14401098  -3.41316593  10.12141306   3.77001170  -4.59634355  -4.77952118 
##          847          848          849          850          851          852 
##  -4.22998830  -5.22998830  -3.00756049  -4.68793237 -10.45802761 -10.00008354 
##          853          854          855          856          857          858 
##  -3.86363305  -5.78699813  -3.86363305  -4.13839949  -4.77952118  -4.87110999 
##          859          860          861          862          863          864 
##  -8.16830727  19.04477814 -10.91597168  -2.95522186  -4.22998830  -5.87858694 
##          865          866          867          868          869          870 
##   0.74758086   5.12889001  -4.59634355  -4.59634355  -2.51223169 -11.23746525 
##          871          872          873          874          875          876 
##  -0.87110999  -2.59634355 -12.65615913  47.65599205  -3.70288626  10.86160051 
##          877          878          879          880          881          882 
##  20.48776831  -7.69540931  -6.42811982  -5.87858694 -14.81690591   8.49524526 
##          883          884          885          886          887          888 
## -10.18326117  17.02982425  -3.86363305 -15.97017575 -10.36643879  -2.51970863 
##          889          890          891          892          893          894 
##  -0.95522186  -1.13839949   5.04477814  -2.50475474  -4.77952118  -4.04681067 
##          895          896          897          898          899          900 
##  -9.35896185  -5.05428762   4.86160051  -3.41316593  -3.51223169  -4.32157711 
##          901          902          903          904          905          906 
##   7.67842289  21.31206763  10.30459069  -4.22998830  -2.77952118  13.99991646 
##          907          908          909          910          911          912 
##  -1.32157711  -7.71036321 309.25972900 100.13636695  23.77374260   1.20552493 
##          913          914          915          916          917          918 
## -14.94587946  -5.32905406  -4.22998830   1.40365645  -9.54213947  -5.78699813 
##          919          920          921          922          923          924 
##   2.12141306  -3.22998830  19.95318933  15.58683407  -7.89354083  -4.96269881 
##          925          926          927          928          929          930 
##   1.31206763   3.13636695  -4.87110999  -4.32157711  -4.13839949   4.13636695 
##          931          932          933          934          935          936 
##  -1.32157711  -5.60382050  -5.32905406  16.13636695   7.13636695   0.49524526 
##          937          938          939          940          941          942 
##  -6.70288626  31.13636695  -6.43559677  -4.22998830  -4.68793237  -2.86363305 
##          943          944          945          946          947          948 
##  24.58683407  12.13636695   7.31206763  -5.51223169  -4.50475474  18.13636695 
##          949          950          951          952          953          954 
##  -2.07671846 -11.74027100 -10.82438286 -13.72345165  -2.24494219 -11.19073812 
##          955          956          957          958          959          960 
##  10.86160051  13.58683407  -3.68793237  -8.80942897 -10.54961642  -5.42064287 
##          961          962          963          964          965          966 
##  -5.23746525  -8.53466253  -5.05428762  -7.61877439   1.57935713  12.13636695 
##          967          968          969          970          971          972 
##  -4.68793237   7.38870255  -0.23746525  12.86160051   5.77001170   8.13636695 
##          973          974          975          976          977          978 
##   8.12889001  -2.42064287   0.36627171  -3.78699813  25.81673883  -1.32157711 
##          979          980          981          982          983          984 
##   9.22047882   9.58683407  -5.14587643   6.48776831   0.31206763   2.49524526 
##          985          986          987          988          989          990 
##  -6.42811982   7.19057103  -3.68793237  -1.13839949 114.28215985   6.31206763 
##          991          992          993          994          995          996 
##   1.94571238  38.03730119  -0.41316593  -4.32157711  55.93075849   0.04477814 
##          997          998          999         1000         1001         1002 
##   3.75505781 -10.00008354  -5.32905406  -4.60382050  -3.32905406   3.94571238 
##         1003         1004         1005         1006         1007         1008 
##  -3.86363305  -1.61877439   2.76253475  -6.33653101  -3.86363305  -3.86363305 
##         1009         1010         1011         1012         1013         1014 
##  -3.86363305   7.77001170  18.11393611  -5.42064287  -4.22998830  -2.32157711 
##         1015         1016         1017         1018         1019         1020 
##  -3.95522186  -1.68793237  -1.32157711  -2.59634355  -4.32905406  -4.13839949 
##         1021         1022         1023         1024         1025         1026 
##  -3.13839949  -3.04681067  -4.22998830   1.58683407  -3.87110999  -3.22998830 
##         1027         1028         1029         1030         1031         1032 
##  -4.59634355  -2.41316593  -4.62625134   3.03730119  -4.32157711  -3.87110999 
##         1033         1034         1035         1036         1037         1038 
##  -3.22998830   0.12889001  -2.41316593  -4.04681067   9.12889001   2.92328154 
##         1039         1040         1041         1042         1043         1044 
##  -0.41316593  -0.98512965 -10.36643879  -4.87110999  -5.61877439  -3.50475474 
##         1045         1046         1047         1048         1049         1050 
##  -4.13839949  -2.77952118  -4.23746525   8.95318933  -4.22998830  -5.32905406 
##         1051         1052         1053         1054         1055         1056 
##   6.19243648 -10.09914930  -3.14587643  -0.87110999  -6.89354083   5.04477814 
##         1057         1058         1059         1060         1061         1062 
##  -5.87858694  -6.42811982  -4.04681067  -7.06924151   7.04477814   5.95318933 
##         1063         1064         1065         1066         1067         1068 
##   1.11393611  -1.32157711  29.74758086   0.12141306  -9.17578422  17.57935713 
##         1069         1070         1071         1072         1073         1074 
##  -5.23746525   1.22047882  -5.07671846   6.48776831  -0.27484998  12.48776831 
##         1075         1076         1077         1078         1079         1080 
##  97.58683407  25.91392399 -12.65615913  96.38309105  -3.51223169   1.20552493 
##         1081         1082         1083         1084         1085         1086 
##  -3.04681067  -5.51223169  22.55692629  -4.32157711  -4.13839949   7.03730119 
##         1087         1088         1089         1090         1091         1092 
##  17.02982425  71.86160051 101.94010088   3.83916967  -0.17578422  -7.98512965 
##         1093         1094         1095         1096         1097         1098 
## -10.36643879  -9.72531710 -10.09167235  -1.32905406   1.48776831   0.04477814 
##         1099         1100         1101         1102         1103         1104 
##  -7.24494219  12.37374866  -6.06176457  26.20552493  -8.16830727  -5.51223169 
##         1105         1106         1107         1108         1109         1110 
##  -2.96269881   8.61860731   4.86160051   2.31206763  -4.41316593  -4.04681067 
##         1111         1112         1113         1114         1115         1116 
## 112.61299581   2.75505781   5.56440323  -7.53466253  -5.69540931  -5.51223169 
##         1117         1118         1119         1120         1121         1122 
##  -4.87110999  -4.59634355  -5.87858694  -5.87858694   0.07655138  -4.41316593 
##         1123         1124         1125         1126         1127         1128 
##  -0.51223169   1.57188018  -8.62625134  -4.41316593  -4.22998830 -12.10662625 
##         1129         1130         1131         1132         1133         1134 
##  -4.59634355  -5.05428762  -4.68793237   1.49524526 -11.00756049  -8.16830727 
##         1135         1136         1137         1138         1139         1140 
##  -4.87110999 -10.82438286  -5.23746525  -3.50475474  -4.68793237  -6.24494219 
##         1141         1142         1143         1144         1145         1146 
##  -9.90849473  -5.32905406 -10.82438286  -5.60382050  -5.05428762  -4.13839949 
##         1147         1148         1149         1150         1151         1152 
##  -4.87110999 -12.83933676  -0.77952118  -6.24494219  -4.13839949  -4.87110999 
##         1153         1154         1155         1156         1157         1158 
##  -1.68793237  -5.32905406  -5.23746525  -7.98512965  -5.42064287  78.28587559 
##         1159         1160         1161         1162         1163         1164 
##  -4.22998830  -2.22998830  -6.51970863  -1.60382050 -12.83933676 -12.35148490 
##         1165         1166         1167         1168         1169         1170 
##  -4.77952118  -9.26737303 -23.46363911  -4.41316593 -10.54961642  -8.90101778 
##         1171         1172         1173         1174         1175         1176 
## -10.18326117  -8.99260659  -9.81690591  -8.35148490  -9.06176457  -5.97017575 
##         1177         1178         1179         1180         1181         1182 
## -10.45802761  -8.07671846  -4.77952118   4.30459069 -14.12158014  -8.25989609 
##         1183         1184         1185         1186         1187         1188 
##  -4.22998830 -10.18326117   0.04477814  -4.13839949  -3.22998830 -11.97017575 
##         1189         1190         1191         1192         1193         1194 
##  -4.60382050 -11.82438286  -5.41316593  -3.87110999  -4.41316593  -6.33653101 
##         1195         1196         1197         1198         1199         1200 
##  -6.33653101  -7.43559677  -4.41316593 -12.74774794  -8.53466253  -9.72531710 
##         1201         1202         1203         1204         1205         1206 
##  29.16814019   8.29711374   8.48029137   1.95318933  -4.68793237 -10.73279405 
##         1207         1208         1209         1210         1211         1212 
##   9.02234730  -4.96269881  -3.87110999   2.95318933  -4.32905406   3.76253475 
##         1213         1214         1215         1216         1217         1218 
##  27.71767307   7.01487035   8.04477814   0.67842289  -7.34400795  -4.68793237 
##         1219         1220         1221         1222         1223         1224 
##  -6.80942897  28.83916967  -5.23746525  -4.32157711  -5.87858694  -5.05428762 
##         1225         1226         1227         1228         1229         1230 
##  -4.87110999  28.99991646  -1.59634355  -5.42064287  -5.23746525  -3.22998830 
##         1231         1232         1233         1234         1235         1236 
##  -3.50475474  -4.77952118  -4.68793237  -5.23746525  30.99991646  -6.97765270 
##         1237         1238         1239         1240         1241         1242 
##   1.86160051  -0.77952118  -0.87110999  -4.59634355  -2.59634355   9.94571238 
##         1243         1244         1245 
##  -5.78699813  -0.68793237  28.84663146
df$ResidBeds <- residuals(model1)

We can plot the residuals as a function of ‘PIT count’ to check for linearity, and for common standard deviation (i.e. that the spread of the residuals about 0 is similar for all values of PIT count):

ggplot(data = df) + 
   geom_point(mapping = aes(x = PIT.Count, y = ResidBeds)) +
   geom_hline(yintercept=0,color="red") +
   geom_smooth(mapping = aes(x = PIT.Count, y = ResidBeds),method=loess,se=FALSE,color="blue")
## `geom_smooth()` using formula = 'y ~ x'

geom_point above creates a scatter plot. The geom_hline adds a horizontal line for y=0, and the color is by default black, so I switched it to red to make it more salient. Finally, geom_smooth adds a smooth fit (not necessarily linear) using the loess smoothing method (method=loess).

Finally, we can do a QQ plot of the residuals to check that the response varies normally about the regression line:

qqnorm(df$ResidBeds, main = "Q-Q Plot of Rediduals")