10.41 Effect on Data Storage

20180721 When the names of the variables within a dataset are changed R does not make a complete new copy of the dataset. Instead, the actual data in the column remains in tack whilst the variable itself (ds) references a new memory location where the new variable names get noted. The underlying data within the table is unaffected.

lobstr::ref(weather)

## █ [1:0x5d6c50f30c60] <tibble[,24]> 
## ├─Date=[2:0x5d6c4c05d0c0] <date> 
## ├─Location=[3:0x5d6c4c262c60] <chr> 
## ├─MinTemp=[4:0x5d6c50f2ffb0] <dbl> 
## ├─MaxTemp=[5:0x5d6c484d1ef0] <dbl> 
## ├─Rainfall=[6:0x5d6c4e2f9ce0] <dbl> 
## ├─Evaporation=[7:0x5d6c40ba1300] <dbl> 
## ├─Sunshine=[8:0x5d6c47085e50] <dbl> 
## ├─WindGustDir=[9:0x5d6c4e4f87f0] <ord> 
## ├─WindGustSpeed=[10:0x5d6c40b4b6b0] <dbl> 
## ├─WindDir9am=[11:0x5d6c476ef0f0] <ord> 
## ├─WindDir3pm=[12:0x5d6c4dfc6e60] <ord> 
## ├─WindSpeed9am=[13:0x5d6c4c50d7f0] <dbl> 
## ├─WindSpeed3pm=[14:0x5d6c4d4b1570] <dbl> 
## ├─Humidity9am=[15:0x5d6c475e2f80] <int> 
## ├─Humidity3pm=[16:0x5d6c513715f0] <int> 
## ├─Pressure9am=[17:0x5d6c41068930] <dbl> 
## ├─Pressure3pm=[18:0x5d6c4c24c870] <dbl> 
## ├─Cloud9am=[19:0x5d6c475f6b50] <int> 
## ├─Cloud3pm=[20:0x5d6c50c90f90] <int> 
## ├─Temp9am=[21:0x5d6c4e876d90] <dbl> 
## ├─Temp3pm=[22:0x5d6c4e4a3af0] <dbl> 
## ├─RainToday=[23:0x5d6c4c05e080] <fct> 
## ├─RISK_MM=[24:0x5d6c49c5b7f0] <dbl> 
## └─RainTomorrow=[25:0x5d6c4c5d97e0] <fct>

lobstr::ref(ds)

## █ [1:0x5d6c4ccd6ed0] <tibble[,24]> 
## ├─date=[2:0x5d6c480f36c0] <date> 
## ├─location=[3:0x5d6c4778f660] <chr> 
## ├─min_temp=[4:0x5d6c49e99400] <dbl> 
## ├─max_temp=[5:0x5d6c498be2d0] <dbl> 
## ├─rainfall=[6:0x5d6c49a794b0] <dbl> 
## ├─evaporation=[7:0x5d6c4a208d70] <dbl> 
## ├─sunshine=[8:0x5d6c4a3c3f50] <dbl> 
## ├─wind_gust_dir=[9:0x5d6c4af8b600] <ord> 
## ├─wind_gust_speed=[10:0x5d6c4b0cdc70] <dbl> 
## ├─wind_dir_9am=[11:0x5d6c49c9a6c0] <ord> 
## ├─wind_dir_3pm=[12:0x5d6c49d912f0] <ord> 
## ├─wind_speed_9am=[13:0x5d6c4b288e50] <dbl> 
## ├─wind_speed_3pm=[14:0x5d6c48745450] <dbl> 
## ├─humidity_9am=[15:0x5d6c4794a840] <int> 
## ├─humidity_3pm=[16:0x5d6c4a57f130] <int> 
## ├─pressure_9am=[17:0x5d6c48900630] <dbl> 
## ├─pressure_3pm=[18:0x5d6c48abb810] <dbl> 
## ├─cloud_9am=[19:0x5d6c4a0545e0] <int> 
## ├─cloud_3pm=[20:0x5d6c4b444030] <int> 
## ├─temp_9am=[21:0x5d6c49179fc0] <dbl> 
## ├─temp_3pm=[22:0x5d6c493351a0] <dbl> 
## ├─rain_today=[23:0x5d6c47d2b490] <fct> 
## ├─risk_mm=[24:0x5d6c494f0380] <dbl> 
## └─rain_tomorrow=[25:0x5d6c4ae149d0] <fct>

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