library(tidyverse) # Easily Install and Load the 'Tidyverse'
library(ggnewscale) # Multiple Fill and Colour Scales in 'ggplot2'
library(gganimate) # A Grammar of Animated Graphics
library(hrbrthemes) # Additional Themes, Theme Components and Utilities for 'ggplot2'
library(rgdal) # Bindings for the 'Geospatial' Data Abstraction Library
library(pals) # Color Palettes, Colormaps, and Tools to Evaluate Them
library(transformr) # Polygon and Path Transformations

# Translation to center of coordinate system ------------------------------

mapa.covid <-
  read_csv("files/datos.csv") %>% 
  select(-id)

mapa.covid %>% head() %>% 
  kable(align = "c") %>%
  kable_styling("striped", full_width = TRUE)

mapa.covid <-
  mapa.covid %>%
  mutate(long = long - mean(long),
         lat = lat - mean(lat))

# Shear effect and Rotation Matrix ------------------------------

# Shear Matrix
shear_matrix <- 
  matrix(c(1,0,0.7,0.5),2,2) %>% t

# Rotation matrix
rotation_matrix <- 
  function(theta){
    matrix(c(cos(theta*pi/180), -sin(theta*pi/180),
             sin(theta*pi/180), cos(theta*pi/180)),
           nrow = 2, ncol = 2, byrow = T) %>% 
      round(digits = 2)
  }