Updated related files

Author: 4n4kin

ggplot2/01. Scatter Plots.html

@@ -1,29 +1,31 @@
-Basic Scatter Plot (*Nothing Fancy*)
-====================================
+Basic Scatter Plot (*Nothing Very Fancy - yet*)
+===============================================
 
 We'll be using the `diamonds` dataset that comes with `ggplot2`.
 
 ###Basic Data Summary###
 
-```r
-require(ggplot2)
-require(gridExtra)
 ```
+## Loading required package: ggplot2
+## Loading required package: gridExtra
+## Loading required package: grid
+```
+
 
 ```r
 diamonds<-diamonds
 summary(diamonds)
 ```
 
 ```
-      carat              cut        color        clarity          depth          table          price             x               y               z        
-  Min.   :0.200   Fair     : 1610   D: 6775   SI1    :13065   Min.   :43.0   Min.   :43.0   Min.   :  326   Min.   : 0.00   Min.   : 0.00   Min.   : 0.00  
-  1st Qu.:0.400   Good     : 4906   E: 9797   VS2    :12258   1st Qu.:61.0   1st Qu.:56.0   1st Qu.:  950   1st Qu.: 4.71   1st Qu.: 4.72   1st Qu.: 2.91  
-  Median :0.700   Very Good:12082   F: 9542   SI2    : 9194   Median :61.8   Median :57.0   Median : 2401   Median : 5.70   Median : 5.71   Median : 3.53  
-  Mean   :0.798   Premium  :13791   G:11292   VS1    : 8171   Mean   :61.8   Mean   :57.5   Mean   : 3933   Mean   : 5.73   Mean   : 5.73   Mean   : 3.54  
-  3rd Qu.:1.040   Ideal    :21551   H: 8304   VVS2   : 5066   3rd Qu.:62.5   3rd Qu.:59.0   3rd Qu.: 5324   3rd Qu.: 6.54   3rd Qu.: 6.54   3rd Qu.: 4.04  
-  Max.   :5.010                     I: 5422   VVS1   : 3655   Max.   :79.0   Max.   :95.0   Max.   :18823   Max.   :10.74   Max.   :58.90   Max.   :31.80  
-                                    J: 2808   (Other): 2531
+##      carat              cut        color        clarity          depth          table          price             x               y               z        
+##  Min.   :0.200   Fair     : 1610   D: 6775   SI1    :13065   Min.   :43.0   Min.   :43.0   Min.   :  326   Min.   : 0.00   Min.   : 0.00   Min.   : 0.00  
+##  1st Qu.:0.400   Good     : 4906   E: 9797   VS2    :12258   1st Qu.:61.0   1st Qu.:56.0   1st Qu.:  950   1st Qu.: 4.71   1st Qu.: 4.72   1st Qu.: 2.91  
+##  Median :0.700   Very Good:12082   F: 9542   SI2    : 9194   Median :61.8   Median :57.0   Median : 2401   Median : 5.70   Median : 5.71   Median : 3.53  
+##  Mean   :0.798   Premium  :13791   G:11292   VS1    : 8171   Mean   :61.8   Mean   :57.5   Mean   : 3933   Mean   : 5.73   Mean   : 5.73   Mean   : 3.54  
+##  3rd Qu.:1.040   Ideal    :21551   H: 8304   VVS2   : 5066   3rd Qu.:62.5   3rd Qu.:59.0   3rd Qu.: 5324   3rd Qu.: 6.54   3rd Qu.: 6.54   3rd Qu.: 4.04  
+##  Max.   :5.010                     I: 5422   VVS1   : 3655   Max.   :79.0   Max.   :95.0   Max.   :18823   Max.   :10.74   Max.   :58.90   Max.   :31.80  
+##                                    J: 2808   (Other): 2531
 ```
 
 ```r
@@ -34,27 +36,35 @@ colnames(diamonds)
 ##  [1] "carat"   "cut"     "color"   "clarity" "depth"   "table"   "price"   "x"       "y"       "z"
 ```
 
-```r
-nrow(diamonds)
-```
-
-```
-## [1] 53940
-```
-
 ```r
 set.seed(56)
-data=diamonds[sample(1:nrow(diamonds),1000),]
+data=diamonds[sample(1:nrow(diamonds),2000),]
 ```
 
 
 ###Plots###
 
+The `ggplot2` package by *Hadley Wickham* follows a layer by layer plot building philosophy. In order to build a plot using `ggplot2` , the ideal way is to think in terms of plotting layers.
+
+The steps involved in creating a plot are as follows:
+
++**Step 1:** Add dataset:         `ggplot(data)`
++**Step 2:** Add geometry(layer): `geom_point(x,y)`
++**Step 3:** Add Plot title/change axes scales/faceting
+
 ####Plot 01####
 
 
+**Create a basic scatter plot:**
+Here:
+`data` is a sample of 2000 observations from diamonds dataset.
+The `null` plot is initialised by using `ggplot()`
+To create a scatterplot, we use `geom_point()` as geometry/layer.
+To add plot title we use `ggtitle()`
+
+
 ```r
-p1=ggplot(data)+
+p1=ggplot(data)+ 
   geom_point(aes(y=price,x=carat))+
   ggtitle('p1: Basic scatter plot on diamonds dataset - Price vs Carats')
 
@@ -65,6 +75,8 @@ p1
 
 ####Plot 02####
 
+To create a scatter plot with colors according to a given factor variable, we use the `color` parameter. It takes in a factor (categorical) variable as input & colors the points according to the components of factor variable.
+
 
 ```r
 p2=ggplot(data)+
@@ -76,6 +88,9 @@ p2
 
 ![plot of chunk Scatter Plot-Color added](figure/Scatter Plot-Color added.png) 
 
+The above plot is exactly same as `p2=p1+geom_point(aes(x=carat,y=price,color=cut))`. If you already have a plot & intend to modify its one aspect using `ggplot2`, you can do it by using the `+` operator along with your plot's layer/geometry specification.
+
+
 ####Plot 03####