*===================================================================================*
* Ado-file: ModPlot Version 1.1
* Author: Shutter Zor(左祥太)
* Affiliation: Accounting Department, Xiamen University
* E-mail: Shutter_Z@outlook.com
* Date: 2024/3/14 launch project
* 2025/2/26 first attempt
* 2025/3/4 fix bug
*===================================================================================*
capture program drop modplot
program define modplot, rclass
version 13
syntax, Model(string) [Plot Scheme(string) Dot Right *]
*- check the model() option
local condition_if = subinword("`model'", "if", "S-Z-if", .)
local condition_in = subinword("`model'", "in", "S-Z-in", .)
if strpos("`condition_if'","S-Z-if")>0 | strpos("`condition_in'","S-Z-in")>0{
dis as error "[if] or [in] can not specified in model() option"
exit 198
}
*- parse dependent, independent, moderate and control variable
local model_text = subinstr("`model'", ",", "++", .)
tokenize "`model_text'", parse("++")
local cmdvlist "`1'"
if strpos("`model_text'","++") != 0 {
local opts ", `4'" // options
}
else{
local opts ""
}
gettoken cmd vlist: cmdvlist // before ,
gettoken depvar indepvars: vlist
gettoken indepvar modctrlvar: indepvars
gettoken modvar ctrlvar: modctrlvar
/*
dis "`depvar'"
dis "`indepvar'"
dis "`modvar'"
dis "`ctrlvar'"
dis "`cmd'"
dis "`cmdvlist'"
dis "`opts'"
*/
*- record independent and moderate variable levels
*- command tab has limitation
capture tab `indepvar'
if _rc == 0 {
local indepvar_level = r(r)
}
else {
local indepvar_level = 3
}
capture tab `modvar'
if _rc == 0 {
local modvar_level = r(r)
}
else {
local modvar_level = 3
}
*- y = coefaX + coefbM + coefcXM + coefd
qui sum `depvar'
local depvar_min = r(min)
local depvar_sd = r(sd)
local depvar_max = r(max)
qui sum `indepvar'
local indepvar_min = r(min)
local indepvar_sd = r(sd)
local indepvar_max = r(max)
qui sum `modvar'
local modvar_min = r(min)
local modvar_sd = r(sd)
local modvar_max = r(max)
*- case1: biclassified X and M
if (`indepvar_level' == 2) & (`modvar_level' == 2) {
*- print moderating regression
dis " "
dis "Your Regression:"
if "`opts'" != "" {
dis as result "`cmd' `depvar' i.`indepvar'##i.`modvar'`ctrlvar'`opts'" _n
dis as input "Regression Result:"
}
else {
dis as result "`cmd' `depvar' i.`indepvar'##i.`modvar'`ctrlvar'" _n
dis as input "Regression Result:"
}
*- moderating regression and record parameters
`cmd' `depvar' i.`indepvar'##i.`modvar' `ctrlvar' `opts'
local coefa = _b[`indepvar_max'.`indepvar']
local coefb = _b[`modvar_max'.`modvar']
local coefc = _b[`indepvar_max'.`indepvar'#`modvar_max'.`modvar']
local coefd = _b[_cons]
}
*- case2: biclassified X and continous M
if (`indepvar_level' == 2) & (`modvar_level' != 2) {
*- print moderating regression
dis " "
dis "Your Regression:"
if "`opts'" != "" {
dis as result "`cmd' `depvar' i.`indepvar'##c.`modvar'`ctrlvar'`opts'" _n
dis as input "Regression Result:"
}
else {
dis as result "`cmd' `depvar' i.`indepvar'##c.`modvar'`ctrlvar'" _n
dis as input "Regression Result:"
}
*- moderating regression and record parameters
`cmd' `depvar' i.`indepvar'##c.`modvar' `ctrlvar' `opts'
local coefa = _b[`indepvar_max'.`indepvar']
local coefb = _b[`modvar']
local coefc = _b[`indepvar_max'.`indepvar'#c.`modvar']
local coefd = _b[_cons]
}
*- case3: continous X and continous M
if (`indepvar_level' != 2) & (`modvar_level' != 2) {
*- print moderating regression
dis " "
dis "Your Regression:"
if "`opts'" != "" {
dis as result "`cmd' `depvar' c.`indepvar'##c.`modvar'`ctrlvar'`opts'" _n
dis as input "Regression Result:"
}
else {
dis as result "`cmd' `depvar' c.`indepvar'##c.`modvar'`ctrlvar'" _n
dis as input "Regression Result:"
}
*- moderating regression and record parameters
`cmd' `depvar' c.`indepvar'##c.`modvar' `ctrlvar' `opts'
local coefa = _b[`indepvar']
local coefb = _b[`modvar']
local coefc = _b[c.`indepvar'#c.`modvar']
local coefd = _b[_cons]
}
*- case4: continous X and biclassified M
if (`indepvar_level' != 2) & (`modvar_level' == 2) {
*- print moderating regression
dis " "
dis "Your Regression:"
if "`opts'" != "" {
dis as result "`cmd' `depvar' c.`indepvar'##i.`modvar'`ctrlvar'`opts'" _n
dis as input "Regression Result:"
}
else {
dis as result "`cmd' `depvar' c.`indepvar'##i.`modvar'`ctrlvar'" _n
dis as input "Regression Result:"
}
*- moderating regression and record parameters
`cmd' `depvar' c.`indepvar'##i.`modvar' `ctrlvar' `opts'
local coefa = _b[`indepvar']
local coefb = _b[`modvar_max'.`modvar']
local coefc = _b[c.`indepvar'#`modvar_max'.`modvar']
local coefd = _b[_cons]
}
*- return moderating results
local function_ll_cons = `coefb' * `modvar_min' + `coefd'
local function_ll_coefx = `coefa' + `coefc' * `modvar_min'
local function_ul_cons = `coefb' * `modvar_max' + `coefd'
local function_ul_coefx = `coefa' + `coefc' * `modvar_max'
local function_ll_dot1_y = `function_ll_coefx' * `indepvar_min' + `function_ll_cons'
local function_ll_dot1_x = `indepvar_min'
local function_ll_dot2_y = `function_ll_coefx' * `indepvar_max' + `function_ll_cons'
local function_ll_dot2_x = `indepvar_max'
local function_ul_dot1_y = `function_ul_coefx' * `indepvar_min' + `function_ul_cons'
local function_ul_dot1_x = `indepvar_min'
local function_ul_dot2_y = `function_ul_coefx' * `indepvar_max' + `function_ul_cons'
local function_ul_dot2_x = `indepvar_max'
local plot_ytitle_y_max = max(`function_ll_dot1_y', `function_ll_dot2_y', `function_ul_dot1_y', `function_ul_dot2_y')
local plot_ytitle_y_min = min(`function_ll_dot1_y', `function_ll_dot2_y', `function_ul_dot1_y', `function_ul_dot2_y')
local plot_xtitle_x_max = max(`function_ll_dot1_x', `function_ll_dot2_x', `function_ul_dot1_x', `function_ul_dot2_x')
local plot_xtitle_x_min = min(`function_ll_dot1_x', `function_ll_dot2_x', `function_ul_dot1_x', `function_ul_dot2_x')
return local mod_func = "`depvar' = `coefa'*`indepvar' + `coefb'*`modvar' + `coefc'*`indepvar'*`modvar' + `coefd'"
return local mod_func_ll = "y = `function_ll_coefx'*x + `function_ll_cons'"
return local mod_func_ul = "y = `function_ul_coefx'*x + `function_ul_cons'"
*- draw a graph
if "`plot'" != "" {
local ylabel_begin = `plot_ytitle_y_min' - 0.5*`depvar_sd'
local ylabel_end = `plot_ytitle_y_max' + 0.5*`depvar_sd'
local xlabel_begin = `plot_xtitle_x_min' - 0.5*`indepvar_sd'
local xlabel_end = `plot_xtitle_x_max' + 0.5*`indepvar_sd'
if "`right'" != "" {
local legend_position = 3
}
else {
local legend_position = 6
}
if "`dot'" == "" {
twoway (function y = `function_ll_coefx'*x + `function_ll_cons' ///
, lp(dash) range(`plot_xtitle_x_min' `plot_xtitle_x_max')) ///
(function y = `function_ul_coefx'*x + `function_ul_cons' ///
, lp(dash) range(`plot_xtitle_x_min' `plot_xtitle_x_max')) ///
, legend(order(1 "Low MV (`modvar'=`modvar_min')" ///
2 "High MV (`modvar'=`modvar_max')") col(1) ///
pos(`legend_position')) ///
ylabel(`ylabel_begin' " " `plot_ytitle_y_min' "Low DV" ///
`plot_ytitle_y_max' "High DV" `ylabel_end' " ", noticks) ///
xlabel(`xlabel_begin' " " `plot_xtitle_x_min' "Low IV" ///
`plot_xtitle_x_max' "High IV" `xlabel_end' " ", noticks) ///
xtitle("") ytitle("") scheme(`scheme') `options'
}
else {
twoway (function y = `function_ll_coefx'*x + `function_ll_cons' ///
, lp(dash) range(`plot_xtitle_x_min' `plot_xtitle_x_max')) ///
(function y = `function_ul_coefx'*x + `function_ul_cons' ///
, lp(dash) range(`plot_xtitle_x_min' `plot_xtitle_x_max')) ///
(scatteri `function_ll_dot1_y' `function_ll_dot1_x', mc(gs10) m(O)) ///
(scatteri `function_ll_dot2_y' `function_ll_dot2_x', mc(gs10) m(O)) ///
(scatteri `function_ul_dot1_y' `function_ul_dot1_x', mc(gs10) m(O)) ///
(scatteri `function_ul_dot2_y' `function_ul_dot2_x', mc(gs10) m(O)) ///
, legend(order(1 "Low MV (`modvar'=`modvar_min')" ///
2 "High MV (`modvar'=`modvar_max')") col(1) ///
pos(`legend_position')) ///
ylabel(`ylabel_begin' " " `plot_ytitle_y_min' "Low DV" ///
`plot_ytitle_y_max' "High DV" `ylabel_end' " ", noticks) ///
xlabel(`xlabel_begin' " " `plot_xtitle_x_min' "Low IV" ///
`plot_xtitle_x_max' "High IV" `xlabel_end' " ", noticks) ///
xtitle("") ytitle("") scheme(`scheme') `options'
}
}
end