Stata undocumented commands and options

Stata undocumented commands and options
Stata undocumented/obsolete commands and options are usually used by limited people such as Stata programmers of StataCorp in developing Stata. However, sometimes I find they are quite handy.

• Analyzing survey data: -svygen- (generating adjusted sampling weights), -svycal- (calibration-adjusted sampling weights)
• Generating the estimate variables of a graph: - twoway__function_gen-, -twoway__histogram_gen-, -twoway__kdensity_gen-
• Calculating margins: -margins, gen()- (create margin-response variables in the current dataset), -margins, saving()- (save margins results to a dataset)
• Programming: -set buildfvinfo- (build extra factor-variables information into parameter estimates), -_coef_table- (displaying estimation results)
• finding more: A list of Stata undocumented command
• -vce()- options and options for survey data analysis: -vce(svy)-  and -vce(unconditional)- are obsolete options of -vce(linearized)-

Stata: output and reuse the estimates of histogram

Stata: Output and reuse the estimates of a histogram
Sometimes we would like to export the estimates of a histogram and make a histogram plot using other software such as Excel.  The undocumented command - twoway__ histogram_gen - can help.

• Stata tip 20: Generating histogram bin variables, for example (modified):
• sysuse auto,clear
• histogram weight, percent bin(20)
• twoway__histogram_gen weight, bin(20) percent gen (hvalue xvalue, replace)
• twoway bar hvalue xvalue, barwidth(.15) bstyle(histogram)
• list hvalue xvalue if !missing(hvalue), sum(hvalue) clean
• or, you can copy columns from the "Data Editor" window and paste them into Excel sheet.
• or use - serset -, the data in the .gph file are stored in the serset format
• sysuse auto,clear
• histogram weight, percent width(100)
• preserve
• serset use,clear
• then, you can copy the first and third columns (such as __000001, __000003) from the "Data Editor" window and paste them into an Excel sheet.
• restore
• - grexport - a user-written ado file, an alternative to -graph export-
• sysuse auto,clear
• histogram weight, percent width(100)
• grexport, list //list results in the result window

Stata: Output the results into Excel tables

Stata: Output the results into Excel tables

• Stata manual: putexcel, putexcel advanced
• Stata blogs: Chuck Huber (2017).Creating Excel tables with putexcel
• part 1: Introduction and formatting
• part 2: Macro, picture, matrix, and formula expressions
• part 3: Writing custom reports for arbitrary variables
• ASCII Codes
• Example: 
  cd c:\temp sysuse auto regress price mpg i.foreign margins foreign mat rtable=r(table)' putexcel set demo.xlsx,sheet(demo) replace local cell1=char(64+1)+string(1) local cell2=char(64+1)+string(5) putexcel `cell1'=matrix(rtable) /// `cell2'=matrix(rtable[1...,1],rtable[1...,5..6],rtable[1...,2]),names

SAS: LSMESTIMATE vs CONTRAST and ESTIMATE

SAS: LSMESTIMATE vs CONTRAST and ESTIMATE
LSMESTIMATE was a new statement in SAS 9.22 and much easier to be used than CONTRAST and ESTIMATE

• Wikipedia.Contrast (Statistics)
• Kiernan (2011). CONTRAST and ESTIMATE Statements Made Easy: The LSMESTIMATE Statement
• Wicklin (2016). How to write CONTRAST and ESTIMATE statements in SAS regression procedures
• A quick guide to writing contrast statements in SAS and SPSS,here is a Chinese version

SAS: how to customize the plots

SAS: How to Customize the Plots

• Usually I prefer to get a dataset of estimates for the plot, then use PROC SGPLOT/GPLOT, R!, or MS Excel plot those estimates.
• Or, modify the template of a statistic plot following the steps:
• Turn on the trace function: "ODS TRACE ON;"; run the PROC XXX; then find the name of default template (such as 'Stat.Lifetest.Graphics.cifPlot'); then "ODS TRACE OFF;"
• Print out the template: "PROC TEMPLATE; SOURCE Stat.Lifetest.Graphics.cifPlot; RUN;"
• Copy the definition from the log window
• Paste it in underscore part: "PROC TEMPLATE; _________; RUN;" and modify the definition part you are interested in, and run it
• Run the PROC XXX again.
• After done: run "PROC TEMPLATE; DELETE Stat.Lifetest.Graphics.cifPlot; RUN;" to set the template as the default format.
• SAS/STAT Document 9.3, 14.3:
• ODS Graphics Template Modification
• Example 22.3 Customizing Survival Plots
• Example 22.5 Customizing Axes and Reference Lines
• SAS/STAT 14.1: Customizing the Kaplan-Meier Survival Plot
• May use the "Tools -> ODS Graphics Editor" to edit these plots after you get them. It's better use SGE format by setting "ODS LISTING SGE=ON; ODS HTML SGE=ON;"
• Slaughter (2010).Using PROC SGPLOT for Quick High-Quality Graphs
• Amruthnath (2013). PROC SGPLOT over PROC GPLOT
• Kuhfeld (2013). Creating and customizing the Kaplan-Meier survival plot in PROC LIFETEST large graphics
• Zender (2011). The Greatest Hits: ODS Essentials Every User Should Know
• Zender (2009). Tiptoe through the Templates
• Smith (2007). The Output Delivery System (ODS) from Scratch
• Wicklin (2012): How to get data values out of ODS graphics

    ODS GRAPHICS ON;
    ODS TRACE ON;
    ODS OUTPUT Histogram=HIST;
      PROC UNIVARIATE DATA=SAShelp.cars NOPRINT;
      VAR invoice;
      HISTOGRAM invoice;
    RUN;
    ODS TRACE OFF;
    PROC PRINT DATA=HIST;RUN;