Nested foreach

[Chris Lam]

Dear all,

I have been struggling with the

foreach

command for the following task:

local Obv profit hkgovsme_result marketing sale_no moti_self
local Sbv sex fail hkgovsme_app intelp esale fund_no esale_eu esale_none sale_no sorted_nation
local Ocv num_busp ft pt gba_ft ebus_12m
local Scv yr_bus pt num_busp buscha_uncertain hkgovsme gba_busyr

foreach T of newlist Sb Sc{
foreach n of local `T'v{
local label: variable label `n'
graph hbar, ///
over(`n') over(tech) ///
stack percent ///
asyvars ///
blabel(bar, position(center) format(%9.0f) color(white) size(2.5)) ///
legend(r(1) size(2)) ///
yline(50)  ///
ytitle("%") ///
b1title("`label'") ///
note("Conditional observation: Startups")

graph export `add'\`T'v_`n'.png, replace
}
}

foreach T of newlist Ob Oc{
foreach n of local `T'v{
local label: variable label `n'
graph hbar, ///
over(`n') over(startup) ///
stack percent ///
asyvars ///
blabel(bar, position(center) format(%9.0f) color(white) size(2.5)) ///
legend(r(1) size(2)) ///
yline(50)  ///
ytitle("%") ///
b1title("`label'") ///
note("Conditional observation: ALL")

graph export `add'\`T'v_`n'.png, replace
}
}

As you may notice, the only difference between the two -foreach- is the following

1. objects in -newlist(.)-: Sb, Sc and Ob, Oc
2. the variables in the - over(.)-: tech, startup

I would like to know if there is any more elegant way to get the same result? I encounter and struggle the similar problem often

Thank you

[Nick Cox]

As for the looping, this is a little simpler and works:

local Sbv sex fail hkgovsme_app intelp esale fund_no esale_eu esale_none sale_no sorted_nation
local Scv yr_bus pt num_busp buscha_uncertain hkgovsme gba_busyr

foreach T in Sb Sc {
   foreach n of local `T'v {
       display "`n'" 
   }
}

The problem however that I noticed was in lines like

 
 graph export `add'\`T'v_`n'.png, replace

The local macro add is not defined in the code you give, but the backslash is certainly wrong. See https://www.stata-journal.com/sjpdf....iclenum=pr0042 and its references.

[Chris Lam]

As for the looping, this is a little simpler and works:

local Sbv sex fail hkgovsme_app intelp esale fund_no esale_eu esale_none sale_no sorted_nation
local Scv yr_bus pt num_busp buscha_uncertain hkgovsme gba_busyr

foreach T in Sb Sc {
foreach n of local `T'v {
display "`n'"
}
}

The problem however that I noticed was in lines like

graph export `add'\`T'v_`n'.png, replace

The local macro add is not defined in the code you give, but the backslash is certainly wrong. See https://www.stata-journal.com/sjpdf....iclenum=pr0042 and its references.

Dear Nick,

Thank you for your reply. I am sorry for the missing information.

The add is defined as follow:

local add C:\Users\econ_ias\Dropbox\CK\CK_Survey\graph\sig_v\

Besides, the desired result is conditioning on startup (tech): processing the loop for variables in local macro Obv and Ocv (Sbv and Scv)

My main concern is that if there are any alternatives that writing one foreach loop that respectively conditions on startup and tech and achieves the desired result.

Any suggestion is appreciated!

Thank you

[Nick Cox]

So the local macro add would cause problems too, as its contents end with a backslash. You need minimally

 
 local add C:\Users\econ_ias\Dropbox\CK\CK_Survey\graph\sig_v/

Your main concern should be getting code that works.

Once you fix the errors pointed out, which you don't mention in your reply, I don't see a way of reducing your code that is a good idea. Making it shorter in this case won't make it clearer.

[Chris Lam]

So the local macro add would cause problems too, as its contents end with a backslash. You need minimally

local add C:\Users\econ_ias\Dropbox\CK\CK_Survey\graph\sig_v/

Your main concern should be getting code that works.

Once you fix the errors pointed out, which you don't mention in your reply, I don't see a way of reducing your code that is a good idea. Making it shorter, in this case, won't make it clearer.

Thank you, one silly question is that I do not understand the problem that backlash.. while I got errors if I do not have the extra backslash in the export syntax if I keep the path of macro local add unchanged, see the following:

 
 graph export `add'\`T'v_`n'.png, replace

Besides, so you mean there is no way of having a conditional item/variable in a loop?
I have encountered this problem many times.. for example in the loop for some variable I would like to condition the observation on b but some on a to draw the graph/table/regression.

[Nick Cox]

I should not be dogmatic. Looking at this again, I see scope for rearranging. If this is closer to what you want, then go for it. Not tested and I am ignoring add.

local Sbv sex fail hkgovsme_app intelp esale fund_no esale_eu esale_none sale_no sorted_nation
local Scv yr_bus pt num_busp buscha_uncertain hkgovsme gba_busyr
local Obv profit hkgovsme_result marketing sale_no moti_self
local Ocv num_busp ft pt gba_ft ebus_12m

local options  over(tech) stack percent asyvars ///
blabel(bar, position(center) format(%9.0f) color(white) size(2.5)) ///
legend(r(1) size(2)) yline(50)  ytitle("%")

foreach T in Sbv Scv Obv Ocv {
    local which = cond(inlist("`T'", "Sbv", "Scv"), "Startups", "ALL")
    foreach n of local T {
         local label: variable label `n'
        
         graph hbar,  over(`n') b1title("`label'") `options' ///
         note("Conditional observation: `which'")

         graph export `T'_`n'.png, replace
    }
}

Note: Crossed with #5. I think something like

local add C:\Users\econ_ias\Dropbox\CK\CK_Survey\graph\sig_v  

graph export `add`/`T'_`n'.png, replace

should work.