Create a raster using ggplot2 without .tif and .shp files

Question

I'm trying to create a raster using ggplot2 for cell_temperature_value but without having .shp and .tif files. Is that possible? Or do I need to find them? My data subset

dt<-structure(list(Cell_temperature_value = c(3.82969190920466, 2.95279360047462, 
2.07589529174459, 1.19899698301455, 0.322098674284518, -0.554799634445516, 
-1.43169794317555, -2.30859625190558, -3, -3, -3, -3, -3, -3, 
-3, -3, -3, -3, 4.91461274282071, 4.03771443409067, 3.16081612536064, 
2.28391781663061, 1.40701950790057, 0.530121199170537, -0.346777109559497, 
-1.22367541828953, -2.10057372701957, -2.9774720357496, -3, -3, 
-3, -3, -3, -3, -3, -3, 5.99953357643665, 5.12263526770661, 4.24573695897658, 
3.36883865024655, 2.49194034151651, 1.61504203278648, 0.738143724056442, 
-0.138754584673592, -1.01565289340363, -1.89255120213366, -2.76944951086369, 
-3, -3, -3), LAT = c(29.570000000321, 29.750000000321, 29.930000000321, 
30.110000000321, 30.290000000321, 30.470000000321, 30.650000000321, 
30.830000000321, 31.010000000321, 31.190000000321, 31.370000000321, 
31.550000000321, 31.730000000321, 31.910000000321, 32.090000000321, 
32.270000000321, 32.450000000321, 32.630000000321, 29.570000000321, 
29.750000000321, 29.930000000321, 30.110000000321, 30.290000000321, 
30.470000000321, 30.650000000321, 30.830000000321, 31.010000000321, 
31.190000000321, 31.370000000321, 31.550000000321, 31.730000000321, 
31.910000000321, 32.090000000321, 32.270000000321, 32.450000000321, 
32.630000000321, 29.570000000321, 29.750000000321, 29.930000000321, 
30.110000000321, 30.290000000321, 30.470000000321, 30.650000000321, 
30.830000000321, 31.010000000321, 31.190000000321, 31.370000000321, 
31.550000000321, 31.730000000321, 31.910000000321), LONG = c(35.2899999657152, 
35.2899999657152, 35.2899999657152, 35.2899999657152, 35.2899999657152, 
35.2899999657152, 35.2899999657152, 35.2899999657152, 35.2899999657152, 
35.2899999657152, 35.2899999657152, 35.2899999657152, 35.2899999657152, 
35.2899999657152, 35.2899999657152, 35.2899999657152, 35.2899999657152, 
35.2899999657152, 35.4699999657152, 35.4699999657152, 35.4699999657152, 
35.4699999657152, 35.4699999657152, 35.4699999657152, 35.4699999657152, 
35.4699999657152, 35.4699999657152, 35.4699999657152, 35.4699999657152, 
35.4699999657152, 35.4699999657152, 35.4699999657152, 35.4699999657152, 
35.4699999657152, 35.4699999657152, 35.4699999657152, 35.6499999657152, 
35.6499999657152, 35.6499999657152, 35.6499999657152, 35.6499999657152, 
35.6499999657152, 35.6499999657152, 35.6499999657152, 35.6499999657152, 
35.6499999657152, 35.6499999657152, 35.6499999657152, 35.6499999657152, 
35.6499999657152), fecha = structure(c(14610, 14610, 14610, 14610, 
14610, 14610, 14610, 14610, 14610, 14610, 14610, 14610, 14610, 
14610, 14610, 14610, 14610, 14610, 14610, 14610, 14610, 14610, 
14610, 14610, 14610, 14610, 14610, 14610, 14610, 14610, 14610, 
14610, 14610, 14610, 14610, 14610, 14610, 14610, 14610, 14610, 
14610, 14610, 14610, 14610, 14610, 14610, 14610, 14610, 14610, 
14610), class = "Date"), cellID = c(1, 19, 37, 55, 73, 91, 109, 
127, 145, 163, 181, 199, 217, 235, 253, 271, 289, 307, 2, 20, 
38, 56, 74, 92, 110, 128, 146, 164, 182, 200, 218, 236, 254, 
272, 290, 308, 3, 21, 39, 57, 75, 93, 111, 129, 147, 165, 183, 
201, 219, 237), year = c(2010, 2010, 2010, 2010, 2010, 2010, 
2010, 2010, 2010, 2010, 2010, 2010, 2010, 2010, 2010, 2010, 2010, 
2010, 2010, 2010, 2010, 2010, 2010, 2010, 2010, 2010, 2010, 2010, 
2010, 2010, 2010, 2010, 2010, 2010, 2010, 2010, 2010, 2010, 2010, 
2010, 2010, 2010, 2010, 2010, 2010, 2010, 2010, 2010, 2010, 2010
)), row.names = c(NA, -50L), class = c("tbl_df", "tbl", "data.frame"
))

Answer 1

You can turn point data into raster data. It depends on exactly what you want the output to look like and resolution you want. For example, you could do something like:

library(ggplot2)

ggplot() +
  geom_raster(
    data = dt ,
    aes(x = LONG, y = LAT, fill = Cell_temperature_value),
    interpolate = TRUE
  )

Output