Added rplotting to lessons

lessons/rplotting/assignment.md

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+---
+title: "Assignment: Plotting in R"
+author: Sarah Meister
+date: 2015-11-09
+published: true
+layout: page
+sidebar: false
+tag:
+    - Lessons
+    - Assignment
+    - Plotting
+    - R
+categories:
+    - Lessons
+    - Plotting
+    - R
+---
+
+# Assignment: Plotting with ggplot2 #
+
+**We will be using the `diamonds` dataframe included in `ggplot2` for all questions **
+
+Try each of these challenges, going from raw data to final plot. Create a file
+in the `practice` repo under `your-name/plotting` called `challenge.R`. The file
+location should look like `your-name/plotting/challenge.R`. To get more practice
+with Git, **add and commit** after completing each graph. Use the `diamonds`
+dataset that comes with R.
+
+1. Use the `qplot()` function to make a scatterplot with x=carat and y=price
+
+2. Now color the plot by the cut. 
+
+3. Change the above scatterplot to a histogram of carat, with the fill color of cut. 
+
+4. Change the binwidth of the histogram to 1
+
+** now to the `ggplot()` function **
+
+5. Use the `ggplot()` function to make an object called `b` with x=color and y=depth. 
+
+6. Make a boxplot out of `b`
+
+7. Add the following titles:
+    * Title: Depth and color of round cut diamonds
+    * x label: Diamond color, from J(worst) to D(best)
+    * y label: Depth (mm)
+
+8. Create a `facet_wrap()` using the clarity attribute. Make 4 columns of facets (Hint: use `ncol`. Modifiy the title to say: Depth and color of round cut diamonds by clarity 
+
+9. Make a correlation heatmap of all the numeric/integer columns of the 
+diamonds dataset. Round the correlations to 3 digits. Use `%>%` piping (and the
+`+` from `ggplot2`) to solve this problem. HINT: the cor function turns your
+data into a matrix. Be sure to convert back into a dataframe.
+
+10. (Combining what was learned last week) Create a point plot of the means of 
+each numerical variable.  Have the variable on the y-axis and the means on the
+x-axis. Make sure to properly label the axes and plot. As a bonus/option, make
+the graph prettier.
+
+11. Expand on challenge 10, but split the means up by `price` (hint: make a new 
+factor variable from `price`) for dollars >2000 ('expensive') and <2000
+('inexpensive').  The graph should have two dots for each variable on the y-axis
+representing the means for each group of `price`. Make sure the labels on the
+plot make sense.
+
+12. Expand on challenge 11, but instead of just plotting the means, plot a line
+indicating the standard deviation (sd). This style of plot is known as a forest
+plot. Hint: Use `geom_errorbarh` for the line of upper and lower `sd`.
+

lessons/rplotting/assignmentAnswers.md

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+# Answers
+
+
+```r
+knitr::opts_chunk$set(eval = FALSE)
+```
+
+
+1. 
+
+```r
+library(ggplot2)
+qplot(carat, price, data=diamonds)
+```
+
+2. 
+
+```r
+qplot(carat, price, data=diamonds, color=cut)
+```
+
+3. 
+
+```r
+qplot(carat, data=diamonds, fill=cut)
+```
+
+4. 
+
+```r
+qplot(carat, data=diamonds, fill=cut, binwidth = 1)
+```
+
+5. 
+
+```r
+b <- ggplot(diamonds, aes(color, depth))
+```
+
+6. 
+
+```r
+b + geom_boxplot()
+```
+
+7. 
+
+```r
+b + geom_boxplot() + labs(title="Depth and color of round cut diamonds", x= "Diamond color, from J(worst) to D(best)", y="Depth (mm)")
+```
+
+8. 
+
+```r
+b + geom_boxplot() + labs(title="Depth and color of round cut diamonds by clarity", x= "Diamond color, from J(worst) to D(best)", y="Depth (mm)") + facet_wrap(~clarity, ncol=4)
+```
+
+9.
+
+```r
+library(tidyr)
+library(dplyr)
+
+diamonds %>%
+  selects (-cut, -color, -clarity) %>%
+  cor() %>%
+  round(2) %>%
+  as.data.frame() %>%
+  add_rownames() %>%
+  gather(Var1, Corr, -rowname) %>%
+  ggplot(aes(Var1, rowname, fill=Corr)) + 
+  geom_tile()
+```
+
+10.
+
+
+```r
+library(ggplot2)
+library(dplyr)
+library(tidyr)
+
+diamonds %>%
+    select(carat, depth, table, price, x, y, z) %>% 
+    gather(Variable, Value) %>% 
+    group_by(Variable) %>% 
+    summarize(mean = mean(Value)) %>% 
+    ggplot(aes(mean, Variable)) +
+    geom_point() +
+    labs(x = 'Mean of the value for the variable',
+         y = 'Variable from the diamonds dataset') +
+    ggtitle('Means of the numerical variables from the diamonds dataset') +
+    theme_bw()
+```
+
+
+11. 
+
+
+```r
+diamonds %>% 
+    mutate(PriceGroup = as.factor(ifelse(price > 2000, 'Expensive', 'Inexpensive'))) %>% 
+    select(PriceGroup, carat, depth, table, x, y, z) %>% 
+    gather(Variable, Value, -PriceGroup) %>% 
+    group_by(PriceGroup, Variable) %>% 
+    summarize(mean = mean(Value)) %>% 
+    ggplot(aes(mean, Variable, shape = PriceGroup)) +
+    geom_point() +
+    labs(x = 'Mean of the value for the variable',
+         y = 'Variable from the diamonds dataset') +
+    ggtitle('Means of the numerical variables from\nthe diamonds dataset by cost')
+```
+
+
+12. 
+
+
+```r
+diamonds %>%
+    mutate(PriceGroup = as.factor(ifelse(price > 2000, 'Expensive', 'Inexpensive'))) %>% 
+    select(PriceGroup, carat, depth, table, x, y, z) %>% 
+    gather(Variable, Value, -PriceGroup) %>% 
+    group_by(PriceGroup, Variable) %>% 
+    summarize(mean = mean(Value),
+              sd = sd(Value)) %>% 
+    ggplot(aes(mean, Variable, shape = PriceGroup)) +
+    geom_point() +
+    geom_errorbarh(aes(xmin = mean - sd, xmax = mean + sd),
+                   height = .25) +
+    labs(x = 'Mean of the value for the variable',
+         y = 'Variable from the diamonds dataset') +
+    ggtitle('Means and SD of the numerical variables from\nthe diamonds dataset by cost') +
+    theme_light()
+
+```

lessons/rplotting/intro.md

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+---
+title: "Introduction: Plotting in R"
+published: false
+author: Sarah Meister
+date: 2015-10-15
+layout: page
+sidebar: false
+tag:
+    - Lessons
+    - Introduction
+    - Plotting
+    - R
+categories:
+    - Lessons
+    - Plotting
+    - R
+permalink: lessons/rplotting/
+---
+
+# Materials for this lesson: #
+
+* [Slides](slides/)
+* [Cheatsheet](cheatsheet/)
+* [Assignment](assignment/)
+* [Resources](/lessons/resources/).