I want to divide the numlist in two groups.

[Guest]

Hi,


I have a loop with 50 values "foreach j of numlist 1/50 {", and I want to divide the numlist in two groups.

In the first group I want the next values N1=1,...,25
In my second group I want the other values N2=26,...50

Because I want this to generate this vars:

PRI_N1_1
PRI_N1_...
PRI_N1_...
PRI_N1_...
PRI_N1_25
PRI_N2_26
PRI_N2_...
PRI_N2_...
PRI_N2_...
PRI_N2_50

Would appreciate any help!

[Braulio Santos]

You need two loops, for example:

​​​​​​​clear
set obs 1
forvalues i = 1/2 {
    forvalues j = 1/25 {
        gen PRI_N`i'_`=`j'+25*(`i'-1)' = .
    }
}

[Guest]

You need two loops, for example:

clear
set obs 1
forvalues i = 1/2 {
forvalues j = 1/25 {
gen PRI_N`i'_`=`j'+25*(`i'-1)' = .
}
}

Thanks for your answer but with " (`i'-1)' " the first var wouldn't be "PRI_N1_0"?

I tried to reply your code and the answer was:

variable PRI_1_0 already defined
r(110);

[Braulio Santos]

No, the first variable would be PRI_N1_1.
`j'+25*(`i'-1) = 1 + 25*(1-1) = 1 + (25*0) = 1

When I run the code:

clear
set obs 1
forvalues i = 1/2 {
    forvalues j = 1/25 {
        gen PRI_N`i'_`=`j'+25*(`i'-1)' = .
    }
}
unab varlist: *
di "`varlist'"

I obtain

PRI_N1_1 PRI_N1_2 PRI_N1_3 PRI_N1_4 PRI_N1_5 PRI_N1_6 PRI_N1_7 PRI_N1_8 PRI_N1_9 PRI_N1_10 PRI_N1_11 PRI_N1_12 PRI_N1_13 PRI_N1_14 PRI_N1_15 PRI_ > N1_16 PRI_N1_17 PRI_N1_18 PRI_N1_19 PRI_N1_20 PRI_N1_21 PRI_N1_22 PRI_N1_23 PRI_N1_24 PRI_N1_25 PRI_N2_26 PRI_N2_27 PRI_N2_28 PRI_N2_29 PRI_N2_ > 30 PRI_N2_31 PRI_N2_32 PRI_N2_33 PRI_N2_34 PRI_N2_35 PRI_N2_36 PRI_N2_37 PRI_N2_38 PRI_N2_39 PRI_N2_40 PRI_N2_41 PRI_N2_42 PRI_N2_43 PRI_N2_44  > PRI_N2_45 PRI_N2_46 PRI_N2_47 PRI_N2_48 PRI_N2_49 PRI_N2_50

It's strange. I have no idea how you got the variable "PRI_1_0".

[Braulio Santos]

The only thing that comes to mind is that there is a copy-paste problem. Sometimes, when you copy code, Stata doesn't read the local macro delimiters (" ` " and " ' ") correctly. Try typing the code.

[Nick Cox]

Another way to do it is pedestrian but likely to be easier to follow.

forval j = 1/25 { 
     gen PRI_N1_`j' = .
} 

forval j = 26/50 { 
     gen PRI_N2_`j' = .           
 }

By the time I have read the nested loops and worked out what they do, I've lost any advantage in writing them that way.

[Guest]

No, the first variable would be PRI_N1_1.
`j'+25*(`i'-1) = 1 + 25*(1-1) = 1 + (25*0) = 1

When I run the code:

clear
set obs 1
forvalues i = 1/2 {
forvalues j = 1/25 {
gen PRI_N`i'_`=`j'+25*(`i'-1)' = .
}
}
unab varlist: *
di "`varlist'"

I obtain

PRI_N1_1 PRI_N1_2 PRI_N1_3 PRI_N1_4 PRI_N1_5 PRI_N1_6 PRI_N1_7 PRI_N1_8 PRI_N1_9 PRI_N1_10 PRI_N1_11 PRI_N1_12 PRI_N1_13 PRI_N1_14 PRI_N1_15 PRI_ > N1_16 PRI_N1_17 PRI_N1_18 PRI_N1_19 PRI_N1_20 PRI_N1_21 PRI_N1_22 PRI_N1_23 PRI_N1_24 PRI_N1_25 PRI_N2_26 PRI_N2_27 PRI_N2_28 PRI_N2_29 PRI_N2_ > 30 PRI_N2_31 PRI_N2_32 PRI_N2_33 PRI_N2_34 PRI_N2_35 PRI_N2_36 PRI_N2_37 PRI_N2_38 PRI_N2_39 PRI_N2_40 PRI_N2_41 PRI_N2_42 PRI_N2_43 PRI_N2_44 > PRI_N2_45 PRI_N2_46 PRI_N2_47 PRI_N2_48 PRI_N2_49 PRI_N2_50

It's strange. I have no idea how you got the variable "PRI_1_0".

Thank you! It has been a great help