1. Pengertian

Regresi Smoothing Spline merupakan salah satu metode nonparametrik bersifat piecewise polynomial, yaitu suatu potonganpotongan polinom yang memiliki sifat tersegmen pada selang k yang terbentuk pada titik-titik knot Wang and Yang (2009). Hal ini berarti fungsi Spline merupakan suatu gabungan beberapa polynomial pada knot-knot dengan suatu cara yang menjamin sifat kontuitas. Sehingga hasil prapemrosesan yang diperoleh dapat lebih akurat. Smoothing Spline memiliki kemampuan yang baik dalam mengidentifikasi bentuk kurva antara umur dan waktu bertahan hidup.

### 2. Data Google Mobility Index dan Covid-19 di Jakarta Juli 2021

library(readxl)
mobilitycovidjakarta <- read_excel(path = "D:/matkul sem 2/linear/data covid jakarta 2021 mobile index.xlsx")
mobilitycovidjakarta 
## # A tibble: 31 x 13
##    Nama_provinsi Tanggal             POSITIF Dirawat Sembuh Meninggal
##    <chr>         <dttm>                <dbl>   <dbl>  <dbl>     <dbl>
##  1 DKI Jakarta   2021-07-01 00:00:00  551009   24184 468461      8528
##  2 DKI Jakarta   2021-07-02 00:00:00  560408   25380 473467      8547
##  3 DKI Jakarta   2021-07-03 00:00:00  570110   27442 479150      8577
##  4 DKI Jakarta   2021-07-04 00:00:00  580595   27687 484949      8652
##  5 DKI Jakarta   2021-07-05 00:00:00  591498   28290 491556      8779
##  6 DKI Jakarta   2021-07-06 00:00:00  600937   29136 497492      8861
##  7 DKI Jakarta   2021-07-07 00:00:00  610303   30418 501199      9042
##  8 DKI Jakarta   2021-07-08 00:00:00  623277   29721 512085      9110
##  9 DKI Jakarta   2021-07-09 00:00:00  636389   26903 526941      9306
## 10 DKI Jakarta   2021-07-10 00:00:00  649309   24273 543867      9357
## # ... with 21 more rows, and 7 more variables: Self_isolation <dbl>,
## #   retail_and_recreation_percent_change_from_baseline <dbl>,
## #   grocery_and_pharmacy_percent_change_from_baseline <dbl>,
## #   parks_percent_change_from_baseline <dbl>,
## #   transit_stations_percent_change_from_baseline <dbl>,
## #   workplaces_percent_change_from_baseline <dbl>,
## #   residential_percent_change_from_baseline <dbl>
a. Positif
plot(mobilitycovidjakarta$Tanggal,mobilitycovidjakarta$POSITIF)

b. Dirawat
plot(mobilitycovidjakarta$Tanggal,mobilitycovidjakarta$Dirawat)

c. Sembuh
plot(mobilitycovidjakarta$Tanggal,mobilitycovidjakarta$Sembuh)

d. Meninggal
plot(mobilitycovidjakarta$Tanggal,mobilitycovidjakarta$Meninggal)

e. Self Isolation
plot(mobilitycovidjakarta$Tanggal,mobilitycovidjakarta$`Self_isolation`)

3. Data Deskriptif

library(jmv)

a. Positif

# Mendapatkan data descriptive menggunakan fungsi descritptive
descriptives(mobilitycovidjakarta, vars = vars(POSITIF, grocery_and_pharmacy_percent_change_from_baseline), freq = TRUE)
## 
##  DESCRIPTIVES
## 
##  Descriptives                                                                            
##  --------------------------------------------------------------------------------------- 
##                          POSITIF     grocery_and_pharmacy_percent_change_from_baseline   
##  --------------------------------------------------------------------------------------- 
##    N                           31                                                   31   
##    Missing                      0                                                    0   
##    Mean                  705204.7                                            -2.161290   
##    Median                727016.0                                            -2.000000   
##    Standard deviation    86507.77                                             4.058709   
##    Minimum               551009.0                                            -13.00000   
##    Maximum               814653.0                                             6.000000   
##  ---------------------------------------------------------------------------------------

b. Dirawat

# Mendapatkan data descriptive menggunakan fungsi descritptive
descriptives(mobilitycovidjakarta, vars = vars(Dirawat, grocery_and_pharmacy_percent_change_from_baseline), freq = TRUE)
## 
##  DESCRIPTIVES
## 
##  Descriptives                                                                            
##  --------------------------------------------------------------------------------------- 
##                          Dirawat     grocery_and_pharmacy_percent_change_from_baseline   
##  --------------------------------------------------------------------------------------- 
##    N                           31                                                   31   
##    Missing                      0                                                    0   
##    Mean                  20398.68                                            -2.161290   
##    Median                20359.00                                            -2.000000   
##    Standard deviation    6343.437                                             4.058709   
##    Minimum               7716.000                                            -13.00000   
##    Maximum               30418.00                                             6.000000   
##  ---------------------------------------------------------------------------------------

c. Sembuh

# Mendapatkan data descriptive menggunakan fungsi descritptive
descriptives(mobilitycovidjakarta, vars = vars(Sembuh, grocery_and_pharmacy_percent_change_from_baseline), freq = TRUE)
## 
##  DESCRIPTIVES
## 
##  Descriptives                                                                            
##  --------------------------------------------------------------------------------------- 
##                          Sembuh      grocery_and_pharmacy_percent_change_from_baseline   
##  --------------------------------------------------------------------------------------- 
##    N                           31                                                   31   
##    Missing                      0                                                    0   
##    Mean                  614735.5                                            -2.161290   
##    Median                604060.0                                            -2.000000   
##    Standard deviation    101497.5                                             4.058709   
##    Minimum               468461.0                                            -13.00000   
##    Maximum               784668.0                                             6.000000   
##  ---------------------------------------------------------------------------------------

d. Meninggal

# Mendapatkan data descriptive menggunakan fungsi descritptive
descriptives(mobilitycovidjakarta, vars = vars(Meninggal, grocery_and_pharmacy_percent_change_from_baseline), freq = TRUE)
## 
##  DESCRIPTIVES
## 
##  Descriptives                                                                             
##  ---------------------------------------------------------------------------------------- 
##                          Meninggal    grocery_and_pharmacy_percent_change_from_baseline   
##  ---------------------------------------------------------------------------------------- 
##    N                            31                                                   31   
##    Missing                       0                                                    0   
##    Mean                   10097.87                                            -2.161290   
##    Median                 9818.000                                            -2.000000   
##    Standard deviation     1148.204                                             4.058709   
##    Minimum                8528.000                                            -13.00000   
##    Maximum                12135.00                                             6.000000   
##  ----------------------------------------------------------------------------------------

e. Self Isolation

# Mendapatkan data descriptive menggunakan fungsi descritptive
descriptives(mobilitycovidjakarta, vars = vars(Self_isolation, grocery_and_pharmacy_percent_change_from_baseline), freq = TRUE)
## 
##  DESCRIPTIVES
## 
##  Descriptives                                                                                  
##  --------------------------------------------------------------------------------------------- 
##                          Self_isolation    grocery_and_pharmacy_percent_change_from_baseline   
##  --------------------------------------------------------------------------------------------- 
##    N                                 31                                                   31   
##    Missing                            0                                                    0   
##    Mean                        59972.65                                            -2.161290   
##    Median                      66581.00                                            -2.000000   
##    Standard deviation          22461.30                                             4.058709   
##    Minimum                     10134.00                                            -13.00000   
##    Maximum                     88295.00                                             6.000000   
##  ---------------------------------------------------------------------------------------------

4. Perbandingan Pendekatan

library(npreg)

a. Positif

mod.ss <- ss(mobilitycovidjakarta$Tanggal,mobilitycovidjakarta$POSITIF, nknots = 10)
mobilitycovidjakarta$prediksi_ss <- mod.ss$y
mobilitycovidjakarta
## # A tibble: 31 x 14
##    Nama_provinsi Tanggal             POSITIF Dirawat Sembuh Meninggal
##    <chr>         <dttm>                <dbl>   <dbl>  <dbl>     <dbl>
##  1 DKI Jakarta   2021-07-01 00:00:00  551009   24184 468461      8528
##  2 DKI Jakarta   2021-07-02 00:00:00  560408   25380 473467      8547
##  3 DKI Jakarta   2021-07-03 00:00:00  570110   27442 479150      8577
##  4 DKI Jakarta   2021-07-04 00:00:00  580595   27687 484949      8652
##  5 DKI Jakarta   2021-07-05 00:00:00  591498   28290 491556      8779
##  6 DKI Jakarta   2021-07-06 00:00:00  600937   29136 497492      8861
##  7 DKI Jakarta   2021-07-07 00:00:00  610303   30418 501199      9042
##  8 DKI Jakarta   2021-07-08 00:00:00  623277   29721 512085      9110
##  9 DKI Jakarta   2021-07-09 00:00:00  636389   26903 526941      9306
## 10 DKI Jakarta   2021-07-10 00:00:00  649309   24273 543867      9357
## # ... with 21 more rows, and 8 more variables: Self_isolation <dbl>,
## #   retail_and_recreation_percent_change_from_baseline <dbl>,
## #   grocery_and_pharmacy_percent_change_from_baseline <dbl>,
## #   parks_percent_change_from_baseline <dbl>,
## #   transit_stations_percent_change_from_baseline <dbl>,
## #   workplaces_percent_change_from_baseline <dbl>,
## #   residential_percent_change_from_baseline <dbl>, prediksi_ss <dbl>

b. Dirawat

mod.ss <- ss(mobilitycovidjakarta$Tanggal,mobilitycovidjakarta$Dirawat, nknots = 10)
mobilitycovidjakarta$prediksi_ss <- mod.ss$y
mobilitycovidjakarta
## # A tibble: 31 x 14
##    Nama_provinsi Tanggal             POSITIF Dirawat Sembuh Meninggal
##    <chr>         <dttm>                <dbl>   <dbl>  <dbl>     <dbl>
##  1 DKI Jakarta   2021-07-01 00:00:00  551009   24184 468461      8528
##  2 DKI Jakarta   2021-07-02 00:00:00  560408   25380 473467      8547
##  3 DKI Jakarta   2021-07-03 00:00:00  570110   27442 479150      8577
##  4 DKI Jakarta   2021-07-04 00:00:00  580595   27687 484949      8652
##  5 DKI Jakarta   2021-07-05 00:00:00  591498   28290 491556      8779
##  6 DKI Jakarta   2021-07-06 00:00:00  600937   29136 497492      8861
##  7 DKI Jakarta   2021-07-07 00:00:00  610303   30418 501199      9042
##  8 DKI Jakarta   2021-07-08 00:00:00  623277   29721 512085      9110
##  9 DKI Jakarta   2021-07-09 00:00:00  636389   26903 526941      9306
## 10 DKI Jakarta   2021-07-10 00:00:00  649309   24273 543867      9357
## # ... with 21 more rows, and 8 more variables: Self_isolation <dbl>,
## #   retail_and_recreation_percent_change_from_baseline <dbl>,
## #   grocery_and_pharmacy_percent_change_from_baseline <dbl>,
## #   parks_percent_change_from_baseline <dbl>,
## #   transit_stations_percent_change_from_baseline <dbl>,
## #   workplaces_percent_change_from_baseline <dbl>,
## #   residential_percent_change_from_baseline <dbl>, prediksi_ss <dbl>

c. Sembuh

mod.ss <- ss(mobilitycovidjakarta$Tanggal,mobilitycovidjakarta$Sembuh, nknots = 10)
mobilitycovidjakarta$prediksi_ss <- mod.ss$y
mobilitycovidjakarta
## # A tibble: 31 x 14
##    Nama_provinsi Tanggal             POSITIF Dirawat Sembuh Meninggal
##    <chr>         <dttm>                <dbl>   <dbl>  <dbl>     <dbl>
##  1 DKI Jakarta   2021-07-01 00:00:00  551009   24184 468461      8528
##  2 DKI Jakarta   2021-07-02 00:00:00  560408   25380 473467      8547
##  3 DKI Jakarta   2021-07-03 00:00:00  570110   27442 479150      8577
##  4 DKI Jakarta   2021-07-04 00:00:00  580595   27687 484949      8652
##  5 DKI Jakarta   2021-07-05 00:00:00  591498   28290 491556      8779
##  6 DKI Jakarta   2021-07-06 00:00:00  600937   29136 497492      8861
##  7 DKI Jakarta   2021-07-07 00:00:00  610303   30418 501199      9042
##  8 DKI Jakarta   2021-07-08 00:00:00  623277   29721 512085      9110
##  9 DKI Jakarta   2021-07-09 00:00:00  636389   26903 526941      9306
## 10 DKI Jakarta   2021-07-10 00:00:00  649309   24273 543867      9357
## # ... with 21 more rows, and 8 more variables: Self_isolation <dbl>,
## #   retail_and_recreation_percent_change_from_baseline <dbl>,
## #   grocery_and_pharmacy_percent_change_from_baseline <dbl>,
## #   parks_percent_change_from_baseline <dbl>,
## #   transit_stations_percent_change_from_baseline <dbl>,
## #   workplaces_percent_change_from_baseline <dbl>,
## #   residential_percent_change_from_baseline <dbl>, prediksi_ss <dbl>

d. Meninggal

mod.ss <- ss(mobilitycovidjakarta$Tanggal,mobilitycovidjakarta$Meninggal, nknots = 10)
mobilitycovidjakarta$prediksi_ss <- mod.ss$y
mobilitycovidjakarta
## # A tibble: 31 x 14
##    Nama_provinsi Tanggal             POSITIF Dirawat Sembuh Meninggal
##    <chr>         <dttm>                <dbl>   <dbl>  <dbl>     <dbl>
##  1 DKI Jakarta   2021-07-01 00:00:00  551009   24184 468461      8528
##  2 DKI Jakarta   2021-07-02 00:00:00  560408   25380 473467      8547
##  3 DKI Jakarta   2021-07-03 00:00:00  570110   27442 479150      8577
##  4 DKI Jakarta   2021-07-04 00:00:00  580595   27687 484949      8652
##  5 DKI Jakarta   2021-07-05 00:00:00  591498   28290 491556      8779
##  6 DKI Jakarta   2021-07-06 00:00:00  600937   29136 497492      8861
##  7 DKI Jakarta   2021-07-07 00:00:00  610303   30418 501199      9042
##  8 DKI Jakarta   2021-07-08 00:00:00  623277   29721 512085      9110
##  9 DKI Jakarta   2021-07-09 00:00:00  636389   26903 526941      9306
## 10 DKI Jakarta   2021-07-10 00:00:00  649309   24273 543867      9357
## # ... with 21 more rows, and 8 more variables: Self_isolation <dbl>,
## #   retail_and_recreation_percent_change_from_baseline <dbl>,
## #   grocery_and_pharmacy_percent_change_from_baseline <dbl>,
## #   parks_percent_change_from_baseline <dbl>,
## #   transit_stations_percent_change_from_baseline <dbl>,
## #   workplaces_percent_change_from_baseline <dbl>,
## #   residential_percent_change_from_baseline <dbl>, prediksi_ss <dbl>

e. Self Isolation

mod.ss <- ss(mobilitycovidjakarta$Tanggal,mobilitycovidjakarta$Self_isolation, nknots = 10)
mobilitycovidjakarta$prediksi_ss <- mod.ss$y
mobilitycovidjakarta
## # A tibble: 31 x 14
##    Nama_provinsi Tanggal             POSITIF Dirawat Sembuh Meninggal
##    <chr>         <dttm>                <dbl>   <dbl>  <dbl>     <dbl>
##  1 DKI Jakarta   2021-07-01 00:00:00  551009   24184 468461      8528
##  2 DKI Jakarta   2021-07-02 00:00:00  560408   25380 473467      8547
##  3 DKI Jakarta   2021-07-03 00:00:00  570110   27442 479150      8577
##  4 DKI Jakarta   2021-07-04 00:00:00  580595   27687 484949      8652
##  5 DKI Jakarta   2021-07-05 00:00:00  591498   28290 491556      8779
##  6 DKI Jakarta   2021-07-06 00:00:00  600937   29136 497492      8861
##  7 DKI Jakarta   2021-07-07 00:00:00  610303   30418 501199      9042
##  8 DKI Jakarta   2021-07-08 00:00:00  623277   29721 512085      9110
##  9 DKI Jakarta   2021-07-09 00:00:00  636389   26903 526941      9306
## 10 DKI Jakarta   2021-07-10 00:00:00  649309   24273 543867      9357
## # ... with 21 more rows, and 8 more variables: Self_isolation <dbl>,
## #   retail_and_recreation_percent_change_from_baseline <dbl>,
## #   grocery_and_pharmacy_percent_change_from_baseline <dbl>,
## #   parks_percent_change_from_baseline <dbl>,
## #   transit_stations_percent_change_from_baseline <dbl>,
## #   workplaces_percent_change_from_baseline <dbl>,
## #   residential_percent_change_from_baseline <dbl>, prediksi_ss <dbl>

4. Perbandingan Pendekatan

library(npreg)

a. Positif

mod.ss <- ss(mobilitycovidjakarta$Tanggal,mobilitycovidjakarta$POSITIF, nknots = 10)
mobilitycovidjakarta$prediksi_ss <- mod.ss$y
mobilitycovidjakarta
## # A tibble: 31 x 14
##    Nama_provinsi Tanggal             POSITIF Dirawat Sembuh Meninggal
##    <chr>         <dttm>                <dbl>   <dbl>  <dbl>     <dbl>
##  1 DKI Jakarta   2021-07-01 00:00:00  551009   24184 468461      8528
##  2 DKI Jakarta   2021-07-02 00:00:00  560408   25380 473467      8547
##  3 DKI Jakarta   2021-07-03 00:00:00  570110   27442 479150      8577
##  4 DKI Jakarta   2021-07-04 00:00:00  580595   27687 484949      8652
##  5 DKI Jakarta   2021-07-05 00:00:00  591498   28290 491556      8779
##  6 DKI Jakarta   2021-07-06 00:00:00  600937   29136 497492      8861
##  7 DKI Jakarta   2021-07-07 00:00:00  610303   30418 501199      9042
##  8 DKI Jakarta   2021-07-08 00:00:00  623277   29721 512085      9110
##  9 DKI Jakarta   2021-07-09 00:00:00  636389   26903 526941      9306
## 10 DKI Jakarta   2021-07-10 00:00:00  649309   24273 543867      9357
## # ... with 21 more rows, and 8 more variables: Self_isolation <dbl>,
## #   retail_and_recreation_percent_change_from_baseline <dbl>,
## #   grocery_and_pharmacy_percent_change_from_baseline <dbl>,
## #   parks_percent_change_from_baseline <dbl>,
## #   transit_stations_percent_change_from_baseline <dbl>,
## #   workplaces_percent_change_from_baseline <dbl>,
## #   residential_percent_change_from_baseline <dbl>, prediksi_ss <dbl>

b. Dirawat

mod.ss <- ss(mobilitycovidjakarta$Tanggal,mobilitycovidjakarta$Dirawat, nknots = 10)
mobilitycovidjakarta$prediksi_ss <- mod.ss$y
mobilitycovidjakarta
## # A tibble: 31 x 14
##    Nama_provinsi Tanggal             POSITIF Dirawat Sembuh Meninggal
##    <chr>         <dttm>                <dbl>   <dbl>  <dbl>     <dbl>
##  1 DKI Jakarta   2021-07-01 00:00:00  551009   24184 468461      8528
##  2 DKI Jakarta   2021-07-02 00:00:00  560408   25380 473467      8547
##  3 DKI Jakarta   2021-07-03 00:00:00  570110   27442 479150      8577
##  4 DKI Jakarta   2021-07-04 00:00:00  580595   27687 484949      8652
##  5 DKI Jakarta   2021-07-05 00:00:00  591498   28290 491556      8779
##  6 DKI Jakarta   2021-07-06 00:00:00  600937   29136 497492      8861
##  7 DKI Jakarta   2021-07-07 00:00:00  610303   30418 501199      9042
##  8 DKI Jakarta   2021-07-08 00:00:00  623277   29721 512085      9110
##  9 DKI Jakarta   2021-07-09 00:00:00  636389   26903 526941      9306
## 10 DKI Jakarta   2021-07-10 00:00:00  649309   24273 543867      9357
## # ... with 21 more rows, and 8 more variables: Self_isolation <dbl>,
## #   retail_and_recreation_percent_change_from_baseline <dbl>,
## #   grocery_and_pharmacy_percent_change_from_baseline <dbl>,
## #   parks_percent_change_from_baseline <dbl>,
## #   transit_stations_percent_change_from_baseline <dbl>,
## #   workplaces_percent_change_from_baseline <dbl>,
## #   residential_percent_change_from_baseline <dbl>, prediksi_ss <dbl>

c. Sembuh

mod.ss <- ss(mobilitycovidjakarta$Tanggal,mobilitycovidjakarta$Sembuh, nknots = 10)
mobilitycovidjakarta$prediksi_ss <- mod.ss$y
mobilitycovidjakarta
## # A tibble: 31 x 14
##    Nama_provinsi Tanggal             POSITIF Dirawat Sembuh Meninggal
##    <chr>         <dttm>                <dbl>   <dbl>  <dbl>     <dbl>
##  1 DKI Jakarta   2021-07-01 00:00:00  551009   24184 468461      8528
##  2 DKI Jakarta   2021-07-02 00:00:00  560408   25380 473467      8547
##  3 DKI Jakarta   2021-07-03 00:00:00  570110   27442 479150      8577
##  4 DKI Jakarta   2021-07-04 00:00:00  580595   27687 484949      8652
##  5 DKI Jakarta   2021-07-05 00:00:00  591498   28290 491556      8779
##  6 DKI Jakarta   2021-07-06 00:00:00  600937   29136 497492      8861
##  7 DKI Jakarta   2021-07-07 00:00:00  610303   30418 501199      9042
##  8 DKI Jakarta   2021-07-08 00:00:00  623277   29721 512085      9110
##  9 DKI Jakarta   2021-07-09 00:00:00  636389   26903 526941      9306
## 10 DKI Jakarta   2021-07-10 00:00:00  649309   24273 543867      9357
## # ... with 21 more rows, and 8 more variables: Self_isolation <dbl>,
## #   retail_and_recreation_percent_change_from_baseline <dbl>,
## #   grocery_and_pharmacy_percent_change_from_baseline <dbl>,
## #   parks_percent_change_from_baseline <dbl>,
## #   transit_stations_percent_change_from_baseline <dbl>,
## #   workplaces_percent_change_from_baseline <dbl>,
## #   residential_percent_change_from_baseline <dbl>, prediksi_ss <dbl>

d. Meninggal

mod.ss <- ss(mobilitycovidjakarta$Tanggal,mobilitycovidjakarta$Meninggal, nknots = 10)
mobilitycovidjakarta$prediksi_ss <- mod.ss$y
mobilitycovidjakarta
## # A tibble: 31 x 14
##    Nama_provinsi Tanggal             POSITIF Dirawat Sembuh Meninggal
##    <chr>         <dttm>                <dbl>   <dbl>  <dbl>     <dbl>
##  1 DKI Jakarta   2021-07-01 00:00:00  551009   24184 468461      8528
##  2 DKI Jakarta   2021-07-02 00:00:00  560408   25380 473467      8547
##  3 DKI Jakarta   2021-07-03 00:00:00  570110   27442 479150      8577
##  4 DKI Jakarta   2021-07-04 00:00:00  580595   27687 484949      8652
##  5 DKI Jakarta   2021-07-05 00:00:00  591498   28290 491556      8779
##  6 DKI Jakarta   2021-07-06 00:00:00  600937   29136 497492      8861
##  7 DKI Jakarta   2021-07-07 00:00:00  610303   30418 501199      9042
##  8 DKI Jakarta   2021-07-08 00:00:00  623277   29721 512085      9110
##  9 DKI Jakarta   2021-07-09 00:00:00  636389   26903 526941      9306
## 10 DKI Jakarta   2021-07-10 00:00:00  649309   24273 543867      9357
## # ... with 21 more rows, and 8 more variables: Self_isolation <dbl>,
## #   retail_and_recreation_percent_change_from_baseline <dbl>,
## #   grocery_and_pharmacy_percent_change_from_baseline <dbl>,
## #   parks_percent_change_from_baseline <dbl>,
## #   transit_stations_percent_change_from_baseline <dbl>,
## #   workplaces_percent_change_from_baseline <dbl>,
## #   residential_percent_change_from_baseline <dbl>, prediksi_ss <dbl>

e. Self Isolation

mod.ss <- ss(mobilitycovidjakarta$Tanggal,mobilitycovidjakarta$Self_isolation, nknots = 10)
mobilitycovidjakarta$prediksi_ss <- mod.ss$y
mobilitycovidjakarta
## # A tibble: 31 x 14
##    Nama_provinsi Tanggal             POSITIF Dirawat Sembuh Meninggal
##    <chr>         <dttm>                <dbl>   <dbl>  <dbl>     <dbl>
##  1 DKI Jakarta   2021-07-01 00:00:00  551009   24184 468461      8528
##  2 DKI Jakarta   2021-07-02 00:00:00  560408   25380 473467      8547
##  3 DKI Jakarta   2021-07-03 00:00:00  570110   27442 479150      8577
##  4 DKI Jakarta   2021-07-04 00:00:00  580595   27687 484949      8652
##  5 DKI Jakarta   2021-07-05 00:00:00  591498   28290 491556      8779
##  6 DKI Jakarta   2021-07-06 00:00:00  600937   29136 497492      8861
##  7 DKI Jakarta   2021-07-07 00:00:00  610303   30418 501199      9042
##  8 DKI Jakarta   2021-07-08 00:00:00  623277   29721 512085      9110
##  9 DKI Jakarta   2021-07-09 00:00:00  636389   26903 526941      9306
## 10 DKI Jakarta   2021-07-10 00:00:00  649309   24273 543867      9357
## # ... with 21 more rows, and 8 more variables: Self_isolation <dbl>,
## #   retail_and_recreation_percent_change_from_baseline <dbl>,
## #   grocery_and_pharmacy_percent_change_from_baseline <dbl>,
## #   parks_percent_change_from_baseline <dbl>,
## #   transit_stations_percent_change_from_baseline <dbl>,
## #   workplaces_percent_change_from_baseline <dbl>,
## #   residential_percent_change_from_baseline <dbl>, prediksi_ss <dbl>
# Hasil plot

plot(mobilitycovidjakarta$Tanggal, mobilitycovidjakarta$workplaces_percent_change_from_baseline, lty = 10, col = 'black', lwd =5)

# add lm fit
abline(coef(lm( mobilitycovidjakarta$workplaces_percent_change_from_baseline ~ mobilitycovidjakarta$Tanggal  , data = mobilitycovidjakarta)), lty = 3, col = 'green', lwd =4)
lines(mobilitycovidjakarta$Tanggal, mobilitycovidjakarta$prediksi_ss1 , lty = 2, col = 'Blue', lwd = 4)
## Warning: Unknown or uninitialised column: `prediksi_ss1`.
lines(mobilitycovidjakarta$Tanggal, mobilitycovidjakarta$prediksi_smsp1, lty = 4, col = 'Orange', lwd = 6)
## Warning: Unknown or uninitialised column: `prediksi_smsp1`.

5. Korelasi Pearson

Korelasi Pearson adalah suatu alat yang meimiliki fungsi menganalisis statistik yang digunakan untuk melihat keeratan hubungan linier antara 2 variabel yang skala datanya adalah interval atau rasio.

a, Positif

cor.test(mobilitycovidjakarta$POSITIF,mobilitycovidjakarta$workplaces_percent_change_from_baseline)
## 
##  Pearson's product-moment correlation
## 
## data:  mobilitycovidjakarta$POSITIF and mobilitycovidjakarta$workplaces_percent_change_from_baseline
## t = 1.0596, df = 29, p-value = 0.2981
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
##  -0.1731184  0.5123545
## sample estimates:
##       cor 
## 0.1930649

b. Sembuh

cor.test(mobilitycovidjakarta$Sembuh,mobilitycovidjakarta$workplaces_percent_change_from_baseline)
## 
##  Pearson's product-moment correlation
## 
## data:  mobilitycovidjakarta$Sembuh and mobilitycovidjakarta$workplaces_percent_change_from_baseline
## t = 1.2263, df = 29, p-value = 0.23
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
##  -0.1436114  0.5343298
## sample estimates:
##       cor 
## 0.2220271

c. Dirawat

cor.test(mobilitycovidjakarta$Dirawat,mobilitycovidjakarta$workplaces_percent_change_from_baseline)
## 
##  Pearson's product-moment correlation
## 
## data:  mobilitycovidjakarta$Dirawat and mobilitycovidjakarta$workplaces_percent_change_from_baseline
## t = -1.0773, df = 29, p-value = 0.2902
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
##  -0.5147307  0.1699860
## sample estimates:
##      cor 
## -0.19617

d. Meninggal

cor.test(mobilitycovidjakarta$Meninggal,mobilitycovidjakarta$workplaces_percent_change_from_baseline)
## 
##  Pearson's product-moment correlation
## 
## data:  mobilitycovidjakarta$Meninggal and mobilitycovidjakarta$workplaces_percent_change_from_baseline
## t = 1.4017, df = 29, p-value = 0.1716
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
##  -0.1124889  0.5565560
## sample estimates:
##       cor 
## 0.2518914

e. Self Isolation

cor.test(mobilitycovidjakarta$Self_isolation,mobilitycovidjakarta$workplaces_percent_change_from_baseline)
## 
##  Pearson's product-moment correlation
## 
## data:  mobilitycovidjakarta$Self_isolation and mobilitycovidjakarta$workplaces_percent_change_from_baseline
## t = -1.1982, df = 29, p-value = 0.2405
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
##  -0.5306901  0.1485833
## sample estimates:
##        cor 
## -0.2171917

Dari output yang telah terbuat dapat disimpulkan bahwa tidak adanya hubungan yang signifikan antara mobilityjakarta Dirawat dan mobilityjakarta workplaces_percent_change_from_baseline (p-value<0,01). Nilai p-value dalam output R dituliskan 0.01321. Nilai koefisien korelasi r adalah sebesar 0.4401926yang menunjukkan hubungan yang lemah dan positif ( berbanding lurus) antara variabel Dirawat dan workplaces_percent_change_from_baseline.

6. Hasil Regresi dengan Pendekatan Smoothing Spline

a. Positif

model <- lm(mobilitycovidjakarta$POSITIF ~ mobilitycovidjakarta$workplaces_percent_change_from_baseline, data = mobilitycovidjakarta)
summary(model)
## 
## Call:
## lm(formula = mobilitycovidjakarta$POSITIF ~ mobilitycovidjakarta$workplaces_percent_change_from_baseline, 
##     data = mobilitycovidjakarta)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -169377  -79643   28079   77994  110669 
## 
## Coefficients:
##                                                              Estimate
## (Intercept)                                                    748143
## mobilitycovidjakarta$workplaces_percent_change_from_baseline     1262
##                                                              Std. Error t value
## (Intercept)                                                       43387   17.24
## mobilitycovidjakarta$workplaces_percent_change_from_baseline       1191    1.06
##                                                              Pr(>|t|)    
## (Intercept)                                                    <2e-16 ***
## mobilitycovidjakarta$workplaces_percent_change_from_baseline    0.298    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 86330 on 29 degrees of freedom
## Multiple R-squared:  0.03727,    Adjusted R-squared:  0.004077 
## F-statistic: 1.123 on 1 and 29 DF,  p-value: 0.2981

b. Dirawat

model <- lm(mobilitycovidjakarta$Dirawat ~ mobilitycovidjakarta$workplaces_percent_change_from_baseline, data = mobilitycovidjakarta)
summary(model)
## 
## Call:
## lm(formula = mobilitycovidjakarta$Dirawat ~ mobilitycovidjakarta$workplaces_percent_change_from_baseline, 
##     data = mobilitycovidjakarta)
## 
## Residuals:
##    Min     1Q Median     3Q    Max 
## -12774  -4487  -1063   4621  10868 
## 
## Coefficients:
##                                                              Estimate
## (Intercept)                                                  17199.48
## mobilitycovidjakarta$workplaces_percent_change_from_baseline   -94.00
##                                                              Std. Error t value
## (Intercept)                                                     3179.50   5.409
## mobilitycovidjakarta$workplaces_percent_change_from_baseline      87.26  -1.077
##                                                              Pr(>|t|)    
## (Intercept)                                                  8.13e-06 ***
## mobilitycovidjakarta$workplaces_percent_change_from_baseline     0.29    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 6327 on 29 degrees of freedom
## Multiple R-squared:  0.03848,    Adjusted R-squared:  0.005327 
## F-statistic: 1.161 on 1 and 29 DF,  p-value: 0.2902

c. Sembuh

model <- lm(mobilitycovidjakarta$Sembuh ~ mobilitycovidjakarta$workplaces_percent_change_from_baseline, data = mobilitycovidjakarta)
summary(model)
## 
## Call:
## lm(formula = mobilitycovidjakarta$Sembuh ~ mobilitycovidjakarta$workplaces_percent_change_from_baseline, 
##     data = mobilitycovidjakarta)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -166758  -93211    5825   83785  171580 
## 
## Coefficients:
##                                                              Estimate
## (Intercept)                                                    672671
## mobilitycovidjakarta$workplaces_percent_change_from_baseline     1702
##                                                              Std. Error t value
## (Intercept)                                                       50586  13.297
## mobilitycovidjakarta$workplaces_percent_change_from_baseline       1388   1.226
##                                                              Pr(>|t|)    
## (Intercept)                                                  7.19e-14 ***
## mobilitycovidjakarta$workplaces_percent_change_from_baseline     0.23    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 100700 on 29 degrees of freedom
## Multiple R-squared:  0.0493, Adjusted R-squared:  0.01651 
## F-statistic: 1.504 on 1 and 29 DF,  p-value: 0.23

d. Meninggal

model <- lm(mobilitycovidjakarta$Meninggal ~ mobilitycovidjakarta$workplaces_percent_change_from_baseline, data = mobilitycovidjakarta)
summary(model)
## 
## Call:
## lm(formula = mobilitycovidjakarta$Meninggal ~ mobilitycovidjakarta$workplaces_percent_change_from_baseline, 
##     data = mobilitycovidjakarta)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -1832.76  -964.89    17.43  1046.12  2058.27 
## 
## Coefficients:
##                                                              Estimate
## (Intercept)                                                  10841.43
## mobilitycovidjakarta$workplaces_percent_change_from_baseline    21.85
##                                                              Std. Error t value
## (Intercept)                                                      567.99  19.087
## mobilitycovidjakarta$workplaces_percent_change_from_baseline      15.59   1.402
##                                                              Pr(>|t|)    
## (Intercept)                                                    <2e-16 ***
## mobilitycovidjakarta$workplaces_percent_change_from_baseline    0.172    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 1130 on 29 degrees of freedom
## Multiple R-squared:  0.06345,    Adjusted R-squared:  0.03115 
## F-statistic: 1.965 on 1 and 29 DF,  p-value: 0.1716

e. Self Isolation

model <- lm(mobilitycovidjakarta$Self_isolation ~ mobilitycovidjakarta$workplaces_percent_change_from_baseline, data = mobilitycovidjakarta)
summary(model)
## 
## Call:
## lm(formula = mobilitycovidjakarta$Self_isolation ~ mobilitycovidjakarta$workplaces_percent_change_from_baseline, 
##     data = mobilitycovidjakarta)
## 
## Residuals:
##    Min     1Q Median     3Q    Max 
## -50195  -8747   3645  16100  32971 
## 
## Coefficients:
##                                                              Estimate
## (Intercept)                                                   47430.8
## mobilitycovidjakarta$workplaces_percent_change_from_baseline   -368.5
##                                                              Std. Error t value
## (Intercept)                                                     11207.2   4.232
## mobilitycovidjakarta$workplaces_percent_change_from_baseline      307.6  -1.198
##                                                              Pr(>|t|)    
## (Intercept)                                                  0.000212 ***
## mobilitycovidjakarta$workplaces_percent_change_from_baseline 0.240534    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 22300 on 29 degrees of freedom
## Multiple R-squared:  0.04717,    Adjusted R-squared:  0.01432 
## F-statistic: 1.436 on 1 and 29 DF,  p-value: 0.2405
mobilitycovidjakarta$prediksi_model <- model$fitted.values
mobilitycovidjakarta
## # A tibble: 31 x 15
##    Nama_provinsi Tanggal             POSITIF Dirawat Sembuh Meninggal
##    <chr>         <dttm>                <dbl>   <dbl>  <dbl>     <dbl>
##  1 DKI Jakarta   2021-07-01 00:00:00  551009   24184 468461      8528
##  2 DKI Jakarta   2021-07-02 00:00:00  560408   25380 473467      8547
##  3 DKI Jakarta   2021-07-03 00:00:00  570110   27442 479150      8577
##  4 DKI Jakarta   2021-07-04 00:00:00  580595   27687 484949      8652
##  5 DKI Jakarta   2021-07-05 00:00:00  591498   28290 491556      8779
##  6 DKI Jakarta   2021-07-06 00:00:00  600937   29136 497492      8861
##  7 DKI Jakarta   2021-07-07 00:00:00  610303   30418 501199      9042
##  8 DKI Jakarta   2021-07-08 00:00:00  623277   29721 512085      9110
##  9 DKI Jakarta   2021-07-09 00:00:00  636389   26903 526941      9306
## 10 DKI Jakarta   2021-07-10 00:00:00  649309   24273 543867      9357
## # ... with 21 more rows, and 9 more variables: Self_isolation <dbl>,
## #   retail_and_recreation_percent_change_from_baseline <dbl>,
## #   grocery_and_pharmacy_percent_change_from_baseline <dbl>,
## #   parks_percent_change_from_baseline <dbl>,
## #   transit_stations_percent_change_from_baseline <dbl>,
## #   workplaces_percent_change_from_baseline <dbl>,
## #   residential_percent_change_from_baseline <dbl>, prediksi_ss <dbl>, ...

Menambahkan Histogram

a. Positif

# Menambahkan Histograms
panel.hist <- function(x, ...) {
    usr <- par("usr")
    on.exit(par(usr))
    par(usr = c(usr[1:2], 0, 1.5))
    his <- hist(x, plot = FALSE)
    breaks <- his$breaks
    nB <- length(breaks)
    y <- his$counts
    y <- y/max(y)
    rect(breaks[-nB], 0, breaks[-1], y, col = rgb(0, 0, 1, alpha = 0.5), ...)
    # lines(density(x), col = 2, lwd = 2) # Uncomment to add density lines
}
# Menyetarakan berdasarkan formula
pairs(mobilitycovidjakarta$POSITIF~mobilitycovidjakarta$workplaces_percent_change_from_baseline, data = mobilitycovidjakarta,
      upper.panel = NULL,         # Disabling the upper panel
      diag.panel = panel.hist)    # Adding the histograms
## Warning in par(usr): argument 1 does not name a graphical parameter

## Warning in par(usr): argument 1 does not name a graphical parameter

# plot method
plot(mobilitycovidjakarta$Tanggal, mobilitycovidjakarta$POSITIF, lty = 10, col = 'black', lwd =5)

#plot(mod.ss)
# add lm fit
abline(coef(lm( mobilitycovidjakarta$POSITIF ~ mobilitycovidjakarta$Tanggal  , data = mobilitycovidjakarta)), lty = 10, col = 'purple', lwd =5)
rug(mobilitycovidjakarta$Tanggal)  # add rug to plot


lines(mobilitycovidjakarta$Tanggal,mod.ss$y , lty = 2, col = 'blue', lwd = 4)

#plot(mod.smsp)

lines(mobilitycovidjakarta$Tanggal, mobilitycovidjakarta$prediksi_model, lty = 2, col = 'cyan', lwd = 4)
legend("topleft", 
       legend = c("Real", "Model SS", "Trends", "Regresi Nonparametrik"), 
       lty = 1:4, col = c("Black","blue","purple","cyan"), lwd = 3, bty = "p")

b. Dirawat

# Menambahkan Histograms
panel.hist <- function(x, ...) {
    usr <- par("usr")
    on.exit(par(usr))
    par(usr = c(usr[1:2], 0, 1.5))
    his <- hist(x, plot = FALSE)
    breaks <- his$breaks
    nB <- length(breaks)
    y <- his$counts
    y <- y/max(y)
    rect(breaks[-nB], 0, breaks[-1], y, col = rgb(0, 0, 1, alpha = 0.5), ...)
    # lines(density(x), col = 2, lwd = 2) # Uncomment to add density lines
}
# Menyetarakan berdasarkan formula
pairs(mobilitycovidjakarta$Dirawat~mobilitycovidjakarta$workplaces_percent_change_from_baseline, data = mobilitycovidjakarta,
      upper.panel = NULL,         # Disabling the upper panel
      diag.panel = panel.hist)    # Adding the histograms
## Warning in par(usr): argument 1 does not name a graphical parameter

## Warning in par(usr): argument 1 does not name a graphical parameter

# plot method
plot(mobilitycovidjakarta$Tanggal, mobilitycovidjakarta$Dirawat, lty = 10, col = 'black', lwd =5)

#plot(mod.ss)
# add lm fit
abline(coef(lm( mobilitycovidjakarta$Dirawat ~ mobilitycovidjakarta$Tanggal  , data = mobilitycovidjakarta)), lty = 10, col = 'purple', lwd =5)
rug(mobilitycovidjakarta$Tanggal)  # add rug to plot


lines(mobilitycovidjakarta$Tanggal,mod.ss$y , lty = 2, col = 'blue', lwd = 4)

#plot(mod.smsp)

lines(mobilitycovidjakarta$Tanggal, mobilitycovidjakarta$prediksi_model, lty = 2, col = 'cyan', lwd = 4)
legend("topleft", 
       legend = c("Real", "Model SS", "Trends", "Regresi Nonparametrik"), 
       lty = 1:4, col = c("Black","blue","purple","cyan"), lwd = 3, bty = "p")

c. Sembuh

# Menambahkan Histograms
panel.hist <- function(x, ...) {
    usr <- par("usr")
    on.exit(par(usr))
    par(usr = c(usr[1:2], 0, 1.5))
    his <- hist(x, plot = FALSE)
    breaks <- his$breaks
    nB <- length(breaks)
    y <- his$counts
    y <- y/max(y)
    rect(breaks[-nB], 0, breaks[-1], y, col = rgb(0, 0, 1, alpha = 0.5), ...)
    # lines(density(x), col = 2, lwd = 2) # Uncomment to add density lines
}
# Menyetarakan berdasarkan formula
pairs(mobilitycovidjakarta$Sembuh~mobilitycovidjakarta$workplaces_percent_change_from_baseline, data = mobilitycovidjakarta,
      upper.panel = NULL,         # Disabling the upper panel
      diag.panel = panel.hist)    # Adding the histograms
## Warning in par(usr): argument 1 does not name a graphical parameter

## Warning in par(usr): argument 1 does not name a graphical parameter

# plot method
plot(mobilitycovidjakarta$Tanggal, mobilitycovidjakarta$Sembuh, lty = 10, col = 'black', lwd =5)

#plot(mod.ss)
# add lm fit
abline(coef(lm( mobilitycovidjakarta$Sembuh ~ mobilitycovidjakarta$Tanggal  , data = mobilitycovidjakarta)), lty = 10, col = 'purple', lwd =5)
rug(mobilitycovidjakarta$Tanggal)  # add rug to plot


lines(mobilitycovidjakarta$Tanggal,mod.ss$y , lty = 2, col = 'blue', lwd = 4)

#plot(mod.smsp)

lines(mobilitycovidjakarta$Tanggal, mobilitycovidjakarta$prediksi_model, lty = 2, col = 'cyan', lwd = 4)
legend("topleft", 
       legend = c("Real", "Model SS", "Trends", "Regresi Nonparametrik"), 
       lty = 1:4, col = c("Black","blue","purple","cyan"), lwd = 3, bty = "p")

d. Meninggal

# Menambahkan Histograms
panel.hist <- function(x, ...) {
    usr <- par("usr")
    on.exit(par(usr))
    par(usr = c(usr[1:2], 0, 1.5))
    his <- hist(x, plot = FALSE)
    breaks <- his$breaks
    nB <- length(breaks)
    y <- his$counts
    y <- y/max(y)
    rect(breaks[-nB], 0, breaks[-1], y, col = rgb(0, 0, 1, alpha = 0.5), ...)
    # lines(density(x), col = 2, lwd = 2) # Uncomment to add density lines
}
# Menyetarakan berdasarkan formula
pairs(mobilitycovidjakarta$Meninggal~mobilitycovidjakarta$workplaces_percent_change_from_baseline, data = mobilitycovidjakarta,
      upper.panel = NULL,         # Disabling the upper panel
      diag.panel = panel.hist)    # Adding the histograms
## Warning in par(usr): argument 1 does not name a graphical parameter

## Warning in par(usr): argument 1 does not name a graphical parameter

# plot method
plot(mobilitycovidjakarta$Tanggal, mobilitycovidjakarta$Meninggal, lty = 10, col = 'black', lwd =5)

#plot(mod.ss)
# add lm fit
abline(coef(lm( mobilitycovidjakarta$Meninggal ~ mobilitycovidjakarta$Tanggal  , data = mobilitycovidjakarta)), lty = 10, col = 'purple', lwd =5)
rug(mobilitycovidjakarta$Tanggal)  # add rug to plot


lines(mobilitycovidjakarta$Tanggal,mod.ss$y , lty = 2, col = 'blue', lwd = 4)

#plot(mod.smsp)

lines(mobilitycovidjakarta$Tanggal, mobilitycovidjakarta$prediksi_model, lty = 2, col = 'cyan', lwd = 4)
legend("topleft", 
       legend = c("Real", "Model SS", "Trends", "Regresi Nonparametrik"), 
       lty = 1:4, col = c("Black","blue","purple","cyan"), lwd = 3, bty = "p")

e. Self Isolation

# Menambahkan Histograms
panel.hist <- function(x, ...) {
    usr <- par("usr")
    on.exit(par(usr))
    par(usr = c(usr[1:2], 0, 1.5))
    his <- hist(x, plot = FALSE)
    breaks <- his$breaks
    nB <- length(breaks)
    y <- his$counts
    y <- y/max(y)
    rect(breaks[-nB], 0, breaks[-1], y, col = rgb(0, 0, 1, alpha = 0.5), ...)
    # lines(density(x), col = 2, lwd = 2) # Uncomment to add density lines
}
# Menyetarakan berdasarkan formula
pairs(mobilitycovidjakarta$Self_isolation~mobilitycovidjakarta$workplaces_percent_change_from_baseline, data = mobilitycovidjakarta,
      upper.panel = NULL,         # Disabling the upper panel
      diag.panel = panel.hist)    # Adding the histograms
## Warning in par(usr): argument 1 does not name a graphical parameter

## Warning in par(usr): argument 1 does not name a graphical parameter

# plot method
plot(mobilitycovidjakarta$Tanggal, mobilitycovidjakarta$Self_isolation, lty = 10, col = 'black', lwd =5)

#plot(mod.ss)
# add lm fit
abline(coef(lm( mobilitycovidjakarta$Self_isolation ~ mobilitycovidjakarta$Tanggal  , data = mobilitycovidjakarta)), lty = 10, col = 'purple', lwd =5)
rug(mobilitycovidjakarta$Tanggal)  # add rug to plot


lines(mobilitycovidjakarta$Tanggal,mod.ss$y , lty = 2, col = 'blue', lwd = 4)

#plot(mod.smsp)

lines(mobilitycovidjakarta$Tanggal, mobilitycovidjakarta$prediksi_model, lty = 2, col = 'cyan', lwd = 4)
legend("topleft", 
       legend = c("Real", "Model SS", "Trends", "Regresi Nonparametrik"), 
       lty = 1:4, col = c("Black","blue","purple","cyan"), lwd = 3, bty = "p")

7. Resrensi

  1. https://rpubs.com/suhartono-uinmaliki/891461

  2. http://users.stat.umn.edu/~helwig/notes/smooth-spline-notes.html

  3. https://www.rumusstatistik.com/2019/06/korelasi-pearson.html

  4. Putu Gita Karlina Jayanti, Rahma Anisa, Muhammad Nur Aidi, Erfiani, Xplore (ISSN:2302-5751), Vol 2 No 2 (2018):15-23, Penerapan Teknik Prapemrosesan Smoothing Spline pada Data Hasil Pengukuran Alat Pemantau Glukosa Darah Non-Invasif