Making a figure with Stata or Excel

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Making a figure with Stata or Excel

• Biostatistics 212
• Lecture 7

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Housekeeping

• Lab 5 issues
• Does your do file run? Make sure!
• Comment correctly
• Final Project questions?
• Print and hand in to Olivia or Allison (5th
  floor) by the end of the day on 9/18/07
• 20 points docked for each 1 day late
• Email or call for help!
• PLEASE DO COURSE EVALUATIONS
• Youll get a link by email

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Final Project, grading

• Grading
• 80 (254 out of 317 possible) required to get a
  Satisfactory score in the class
• Also need to turn in all the Labs, even if they
  are late

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Final Project, grading

• Final Project will count for 150/317 points
• Table 75 points
• 35 for do file log
• Housekeeping commands open/close log, use
  dataset, etc
• Analysis generate numbers in the Table
• 40 for Table itself
• Architecture
• Documentation
• Formatting/appearance

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Final Project, grading

• Final Project will count for 150/317 points
• Figure 75 points
• 35 for do file log
• Housekeeping commands open/close log, use
  dataset, etc
• Analysis
• 40 for Figure itself
• Design
• Documentation
• Formatting/appearance

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Final Project, grading

• Advice
• Find a classmate, give them your Table and
  Figure, and get their critiques.
• See if they can understand it without any verbal
  explanation

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Final Project, grading

• Extra credit
• 10 points extra credit and bragging rights for
  the most artistic, creative, and clear figure
  turned in

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Today...

• Figure basics
• Why make a figure?
• Types of figures
• Elements of a figure
• Steps in making a figure with Excel
• Steps in making a figure with Stata
• Demos

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Figures

• Figures are GOOD for presenting overall effects
• Figure are NOT GOOD for presenting specific
  measurements

Browner, W. Publishing and Presenting Clinical
Research
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Figures

• A picture is worth a thousand words

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Figures

• A picture is worth a thousand words

How many words is this picture worth?
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Figures

• A picture is worth a thousand words

48 of CARDIA participants consume alcohol
moderately.
How many words is this picture worth?
Worth 7 words
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Figures

• A picture is worth a thousand words

How many words is this picture worth?
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Figures

• A picture is worth a thousand words

White Black Drinks/day n1935 n1727 0 40 5
7 0.1-0.9 39 26 1-1.9 13 9 2 8 8
How many words is this picture worth?
Worth 1 small table
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Figures

• A picture is worth a thousand words

How many words is this picture worth?
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Figures

• A picture is worth a thousand words

with CAC Abstainer Mod drinker Black
women .047 .036 White women .054 .049 Black
men .068 .132 White men .180 .167
How many words is this picture worth?
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Figures

• A picture is worth a thousand words

How many words is this picture worth?
Worth A thousand words?
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Figures

• A picture is worth a thousand words

How many words is this picture worth?
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Figures

• A picture is worth a thousand words

How many words is this picture worth?
Worth 968 data points lines gt 1000 words?
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Figures

• A picture is worth a thousand words
• Guidelines
• Figures should have a minimum of 4 data points
• Convey important effects, or interactions

Browner, W. Publishing and Presenting Clinical
Research
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Steps in making an Excel figure

• Sketch the Figure, with title
• Try several versions
• Point should be clear at a glance
• Requires some artistic vision

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Steps in making an Excel figure

• Make a dummy TABLE
• Contains the data for the figure
• Doesnt have to look nice

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Steps in making an Excel figure

• Make a dummy TABLE
• Contains the data for the figure
• Doesnt have to look nice
• Write a .do file to fill in the table

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Steps in making an Excel figure

• Make a dummy TABLE
• Contains the data for the figure
• Doesnt have to look nice
• Write a .do file to fill in the table
• Copy and paste from log file into the Table

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Steps in making an Excel figure

• Make a dummy TABLE
• Contains the data for the figure
• Doesnt have to look nice
• Write a .do file to fill in the table
• Copy and paste from log file into the Table
• Use the Chart Wizard to create the Figure

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Steps in making an Excel figure

• Make a dummy TABLE
• Contains the data for the figure
• Doesnt have to look nice
• Write a .do file to fill in the table
• Copy and paste from log file into the Table
• Use the Chart Wizard to create the Figure
• Format format format til it looks nice

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Stata vs. Excel for Figures

• Excel
• Flexible and intuitive point-and-click figures
• Easy to create and modify
• Flexible, more options, error bars, adjusted
  estimates, etc
• But
• Requires an extra step copy/pasting to Excel
• Harder to reproduce
• Much harder to do scatter plots

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Stata vs. Excel for Figures

• Stata
• Can create very customizable figures using 1
  complex Stata command
• Easy to recreate simple do file
• No error
• Scatter plots are MUCH easier with Stata
• But
• Harder to create the first time? - no point and
  click
• A little less flexible?

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Steps in making a Stata figure

• Sketch the figure

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Steps in making a Stata figure

• Sketch the figure
• Write a do file

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Steps in making a Stata figure

• Sketch the figure
• Write a do file
• Compose the command using the dialog box
• Get the syntax down, multiple iterations
• Transfer to your do file and edit

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Steps in making a Stata figure

• Sketch the figure
• Write a do file
• Compose the command using the dialog box
• Get the syntax down, multiple iterations
• Transfer to your do file and edit
• Produce graph and edit more?
• Graph editor function new feature!

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Steps in making a Stata figure

• Sketch the figure
• Write a do file
• Compose the command using the dialog box
• Get the syntax down, multiple iterations
• Transfer to your do file and edit
• Produce graph and edit more?
• Graph editor function new feature!
• May need additional Stata commands for p-values,
  figure legend, etc

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Pay attention to

• Formatting!
• Make it look nice and professional, but not gaudy

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Pay attention to

• Labeling!
• Your figure should be understandable by itself
• Include important p-values

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Pay attention to

• The Figure Legend!
• Title, explanations, extra p-values, etc
• Separate section in manuscript or at bottom of
  page depends on journal

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Stata commands intro

• Pie charts
• graph pie, over(catvar)
• Bar graphs
• graph bar (mean) yvar1 yvar2, over(catvar1)
  over(catvar2) asyvars
• Box plots
• graph box contvar1 contvar2, over(catvar1)
  over(catvar2)
• Scatter plots
• twoway (graphtype yvar xvar) (graphtype yvar
  xvar)
• Scatter, line, connect, lowess, lfit, qfit, etc

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Demo

• Pie charts
• Bar charts
• Twoway plots
• Formatting options

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• twoway (scatter dfev1 cumpy10 if menthol11,
  msymbol(plus) msize(small) mcolor(black)) ///
• (scatter dfev1 cumpy10 if
  menthol10, msymbol(circle_hollow)) ///
• (line m cumpy10 if menthol11,
  sort clcolor(black) clpat(dash) clwidth(thick))
  ///
• (line nm cumpy10 if menthol10,
  sort clcolor(black) clpat(solid) clwidth(thick))
  ///
• , ytitle(Change in FEV1
  (milliliters), size(large)) yscale(titlegap(5))
  ///
• xtitle(Pack-years of exposure to
  tobacco, size(large)) ///
• xscale(titlegap(3)) ///
• legend(order(1 "Menthol smokers"
  2 "Non-menthol smokers" 3 "Menthol regression"
  ///
• 4
  "Non-menthol regression")) ///
• scheme(s1mono) ///
• graphregion(fcolor(none)
  lcolor(none) ifcolor(none) ilcolor(none)) ///
• plotregion(fcolor(none)
  lcolor(none) ifcolor(none) ilcolor(none))

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• graph bar (mean) cac ///
• , over(modalc) ///
• over(racegender) ///
• asyvars ///
• ytitle(Prevalence of coronary
  calcification) ///
• title("Prevalence of coronary
  calcification in moderate drinkers and
  abstainers", ///
• size(medium) span) ///
• subtitle("By race and gender",
  size(medsmall))

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Summary figure tips

• Only use a Figure if
• There is an important message to convey
• The visual will be more compelling and clear
• Try using both Stata and Excel
• Stata will be harder at first, but often worth it
• Browner book, Stata book both helpful
• Document, label, and be creative

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Thats it!

• Thanks for your active participation in the
  course.