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#-----------------------------------------------------------------------------#
#-----------------------------------------------------------------------------#
#                 R in Action - Basic Graphs 
#             - Bar Plots
#             - Pie charts
#             - Fan plots
#             - Histogram
#             - Kernel Density Plot
#             - Box plot
#             - Dot plot

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#####################################################
# -------- Aggregation and Restructuring -----------#
#####################################################

############
#Transpose
############
cars <- mtcars[1:5, 1:4]
t(cars)

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#####################################################
# ---------- User Written Function -----------------#
# - objects in the function are local to the function
# - object returned can be any data type
#####################################################

mystats <- function(x, parametric=TRUE, print=FALSE) {
  if (parametric) {
    center <- mean(x); spread <- sd(x) 
  } else {

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###################################################
# ----------------Flow Control -------------------#
# For Looping
# WHILE Looping
# IF-ELSE Conditional Execution
# IFELSE Conditional Execution
# SWITCH Conditional Execution
###################################################

# For Looping

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###########################################
##           Other Useful Functions      ##
###########################################

# remove a self-written function from memory
rm('knn')

# length of object
x <- length(c(2,5,6,7))
x

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###################################################
### Apply Functions to Matrices and Data Frames ###
###################################################

# One of the interesting features of R functions is that they can be applied to a variety of
# data objects (scalars, vectors, matrices, arrays, and data frames).

b <- c(1.243, 5.654, 2.99)
round(b)

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###########################################
##           Character Function          ##
###########################################

# Number of characters
x <- c("ab", "cde", "fghij")
a <- length(x)
b <- nchar(x[3]) # returns 5

# substring

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#################################################
##             Probability  Functions          ##
#################################################

########################
# Normal Distribution 
#  - density (dnorm)
#  - distribution (pnorm)
#  - quantile (qnorm) 
#  - random deviate generation (rnorm)

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#################################################
##             Basic Stats Functions           ##
#################################################

# quantile(x,probs)         -- Quantiles where x is the numeric vector where 
#                              quantiles are desired
#                           -- y <- quantile(x, c(0.3, 0.84))
# range(x)                  -- Range
#                           -- range(c(1,2,3,4)) returns c(1,4)
#                           -- diff(range(c(1,2,3,4))) returns 3

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#-----------------------------------------------------------------------------#
#-----------------------------------------------------------------------------#
#                 R in Action - Advanced Data Management                      # 
#-----------------------------------------------------------------------------#
#-----------------------------------------------------------------------------#

#################################################
##             Basic Math Functions            ##
#################################################