**************************
*** First steps
**************************
cd d:/Stata // This should replaced by the working directory of your own choice
set more off
capture log close
log using week3.txt,replace
sysuse auto,clear
**************************
*** One variable graphs
**************************

*** Histogram
// basic command:
histogram mpg
// defaut is density plots, to plot fraction and frequency:
histogram mpg, frequency
histogram mpg, fraction
histogram mpg, percent
// add a normal density to the graph
histogram mpg, normal
// add a kernel density to the graph
histogram mpg, kdensity
// For discrete variables:
histogram rep78, percent discrete width(.5)
histogram foreign, percent discrete

*** Bar
// basic command:
graph bar price
// to get price by repair records:
graph bar price,by(rep78)
// to plot bars by repair records on the same graph
graph bar price,over(rep78)
// plot over repair records and foreign
graph bar price,over(foreign) over(rep78)
// the variable labels look messy. Want a better version:
// as a review of the last session:
label define flb 0 "D" 1 "F"
label values foreign flb
graph bar price,over(foreign) over(rep78)
// Change the look of the bars
graph bar price, over(foreign) over(rep78) bar(1,color(black))
**************************
*** Twoway Graphs
**************************
// basic command:
twoway scatter mpg weight
// add a fitted line (overlay graphs)
twoway (scatter mpg weight) (lfit mpg weight)
// label makers
twoway (scatter mpg weight,mlabel(make)) (lfit mpg weight)
// use color to indicate foreign and domestic cars:
twoway (scatter mpg weight if foreign==0) (scatter mpg weight if foreign==1)
// edit the legend
twoway (scatter mpg weight if foreign==0) (scatter mpg weight if foreign==1), legend(label(1 "Domestic") label(2 "Foreign"))
// use symbols and color
twoway (scatter mpg weight if foreign==0,msymbol(O) mcolor(black)) (scatter mpg weight if foreign==1,msymbol(X) mcolor(black)), legend(label(1 "Domestic") label(2 "Foreign"))
// add title to the graphs
twoway (scatter mpg weight),title("Mileage and Weight")

**************************
*** Save and Export
**************************
// save graphs in Stata format for future edits
twoway scatter mpg weight,saving(g1,replace)
twoway scatter price weight,saving(g2,replace)
// combine multiple graphs
graph combine g1.gph g2.gph
// export graphs
graph export graph.png,width(2048) replace

**************************
*** Before you go
**************************
log close

************************************
*** Creating the graphs included in my slides
************************************
cd "d:\Dropbox\Courses\Teaching\EC204\week 3"
sysuse auto,clear
histogram rep78, percent discrete width(.5)
graph export histogram.png,width(2048) replace
label define flb 0 "D" 1 "F"
label values foreign flb
graph bar price,over(foreign) over(rep78) 
graph export bar.png,width(2048) replace
graph twoway (scatter mpg weight) (lfit mpg weight)
graph export twoway.png,width(2048) replace