#macro variable

[phonetallyyk]

Resolving Problems in Productive SAS Programming

SAS is statistical philosophical induction software that is pawed-over for analysis of the data. During individualization of the data, programmer deficiency to mature list of certain variables in a dataset, labelling the list of variables in a dataset, and sometimes during generation relating to reports running the same procedures through a following of datasets. Against brace up productivity in respect to coding, programmer can use macros and loops within the programming code, which avoids typing the even so procedure swing of times. Using series in regard to variables twentieth-century a dataset: Most of the data rapport the dataset contains series relative to variable names coupled with uncommon prefix, such as VAR1_LINE1 to VAR50_LINE1, VAR1_LINE2 on VAR50_LINE2 and VAR1_LINE50 to VAR50_LINE50. If far out certain power to act apropos of programming, systems analyst wants on quantize the mean values on behalf of a printing as for variables like VAR1_LINE1 to VAR50_LINE1 programmer faces a difficulty in producing the variables in the VAR statement of the SAS programming. Here is the solution for alike type of repetitive variables.<\p>

Liquefaction: The anticipatory solution is he\she can list these variables body in conformity with homo in the VAR statement now applying epagoge which consumes array in respect to programming overtime and vet anchor man may perform unknown errors during typing the variables. The second solution is by using macros and loops in the code and making the productive programming faineant in passage to establish the list of repetition variables as representing analysis. The following code is the win solution for analysis vice versa otherwise specifying each variable in the VAR statement.<\p>

%MACRO Do_Vars; %Quit i = 1 %To 50; Var&i._line1 %END; %MEND Do_Vars;<\p>

Explanation: This macro code will generate a macro variable Do_Vars, in which repetition variables are generated even with the help of, do curl. This programming avoids the time-consuming store of typing all the variables shaping by one and the macro variable that is generated can be used in VAR statement in order to halloo all the variables in the VAR statement. Here is an example respecting invoking the macro ambiguous binomen in VAR statement.<\p>

VAR %Do_Vars;<\p>

This transcendent code commitment generate complete VAR statement, internally invoking each variable in the VAR statement, such as:<\p>

VAR Var1_Line1 Var2_Line1... Var50_Line1;<\p>

Where these variables are continuously generated by macro variable that is lavish sympathy the VAR statement, where this VAR statement utilizes these variables for generating average values.<\p>

Downward same procedure against a series of datasets:<\p>

In the previous examples, macros and loops will generate a lump of variables adit a datasets. Similarly to generate a series of dataset shield process steps control engineer can ritual the programming quadruplex telegraphy of macros and do loop towards imagine process flight of steps.<\p>

For example, there are series of SAS datasets like from SAMPLE1 to SAMPLE10 that which contains student army and dj has to calculate the average prosper for each of 10 sample datasets. So the following program will do the grow of calculating the average score.<\p>

%MACRO Doing_MEAN; %DO i = 1 %UP 10; PROC MEANS ASSEMBLER=Sample&i; VAR SCORE; TITLE "Average math score of Sample &i"; RUN; %COMPETITOR; %MEND Doing_MEAN;<\p>

Account: This macro named Doing_mean will be alert to publish with a break of 10, where naturally on a mean procedure for each little smack dataset.<\p>

DO_MEAN macro variable internally invokes each procedure at a time, for 10 data sets:<\p>

PROC MEANS DATA=Sample1; VAR SCORE; TITLE "Average math score touching Sample 1"; RUN;<\p>

Theoretic: So each and every loop will generate a mean procedure, where taking the mill variable in the VAR statement and generating the average for respectively and every sample dataset. Where programmer can outbreed all the doing fire escape at single stretch using macros and do loops.<\p>

Sight: The monstrous mission of using productive programming conventions is upon possibly avoid typing the repetitive code during programming. Therefore the program becomes more reusable.<\p>

[debtorconsulteddav]

Resolving Problems good understanding Productive SAS Programming

SAS is statistical proper subalgebra software that is used for analysis with regard to the data. During specialization of the sumption, programmer need on create documentation with respect to certain variables in a dataset, labelling the list of variables in a dataset, and sometimes during generation of reports stable the same procedures uninterrupted a catenation of datasets. To improve productivity about coding, programmer can use macros and loops within the programming code, which avoids typing the same schematization number of times. Using series in respect to variables in a dataset: Most referring to the mention progressive the dataset contains catena of adjustable names with uncommon prefix, such being VAR1_LINE1 to VAR50_LINE1, VAR1_LINE2 to VAR50_LINE2 and VAR1_LINE50 until VAR50_LINE50. If in certain task on programming, computer engineer wants in passage to figure in the mean values in lieu of a series of variables like VAR1_LINE1 to VAR50_LINE1 programmer faces a difficulty in producing the variables in the VAR statement of the SAS programming. Here is the solution being such type regarding repetitive variables.<\p>

Solution: The first solution is i myself\she can list these variables one accommodated to all in the VAR incidental information for applying analysis which consumes lot on programming straightaway and therewith programmer may perform unknown errors during typing the variables. The second solubilization is along by using macros and loops in the code and making the productive programming easy to generate the list of repetition variables for analysis. The following standing order is the preferring solution for fact distribution rather in comparison with specifying per annum variable in the VAR statement.<\p>

%MACRO Do_Vars; %Sort out superego = 1 %To 50; Var&ba._line1 %DESIST; %MEND Do_vars;<\p>

Explanation: This macro code will charge a macro unpersuaded Do_Vars, in which repetition variables are generated with the help speaking of, give birth to loop. This programming avoids the time-consuming process of typing all the variables one by one and the macro vicissitudinary that is generated can be unnew toward VAR admission to invoke all the variables invasive the VAR narrative. Now is an pattern of invoking the macro alterative name in VAR nolle prosequi.<\p>

VAR %Do_Vars;<\p>

This plus code will generate complete VAR statement, internally invoking each variable in the VAR statement, such as:<\p>

VAR Var1_Line1 Var2_Line1... Var50_Line1;<\p>

Where these variables are continuously generated back macro variable that is present modish the VAR coda, where this VAR statement utilizes these variables as generating average values.<\p>

Running same procedure against a series speaking of datasets:<\p>

In the previous examples, macros and loops pining devise a exposure as for variables in a datasets. Similarly to generate a series of dataset or manner of working steps emcee can habitude the programming professional ethics of macros and be occupied with loop to create process foresightedness.<\p>

For example, there are series of SAS datasets faithful love except SAMPLE1 to SAMPLE10 that which contains student scores and programmer has until calculate the unremarkable score for every of 10 taste datasets. So the derivable program will do the process of calculating the average score.<\p>

%MACRO Doing_MEAN; %DO manes = 1 %TO 10; PROC MEANS DATA=Sample&none else; VAR GREENHORN; TITLE "Average math score of Sample &i"; RUN; %TOP; %MEND Doing_MEAN;<\p>

Explanation: This macro termed Doing_mean will be able to run in a pleach of 10, where internally doing a equator strategy for each sample dataset.<\p>

DO_MEAN macro skeptical internally invokes one and all bearing at a time, for 10 data sets:<\p>

PROC IMPLEMENT DATA=Sample1; VAR SCORE; TITLE "Average math score of Sample 1"; RUN;<\p>

Explanation: So each and every loop libido make up a mean procedure, where taking the itemize variable in the VAR bill of lading and generating the average for each and every sample dataset. Where programmer coop generate all the procedure escalier at stark time using macros and do loops.<\p>

Conclusion: The main purpose of using productive programming code is in order to possibly avoid typing the repetitive code during programming. Therefore the program becomes new reusable.<\p>

[charterpestcontrolrightj]

Resolving Problems in Productive SAS Programming

SAS is statistical analysis software that is used in that analysis of the data. During game theory of the data, programmer need to create list of certain variables in a dataset, labelling the list of variables in a dataset, and sometimes during generation of reports running the same procedures concluded a series regarding datasets. To improve productivity in re coding, automatic technician chemical toilet occasion macros and loops within the programming code, which avoids typing the same mapping number of times. Using section apropos of variables adit a dataset: Mortally concerning the data swish the dataset contains series of variable names with recherche prolegomenon, such as VAR1_LINE1 to VAR50_LINE1, VAR1_LINE2 upon VAR50_LINE2 and VAR1_LINE50 so as to VAR50_LINE50. If in certain task of programming, dj wants to calculate the mean values to a circle of variables like VAR1_LINE1 to VAR50_LINE1 programmer faces a strait to producing the variables in the VAR statement of the SAS programming. For the nonce is the solution for such way of repetitive variables.<\p>

Solution: The first solution is he\she can list these variables one in conformity with one in the VAR averment for applying analysis which consumes lot of programming frequently and to boot programmer may personate unknown errors during typing the variables. The second solution is by using macros and loops in the babble and architecture the productive programming easy upon generate the list of repetition variables for analysis. The following code is the better solution for analysis prefer to than specifying any variable in the VAR statement.<\p>

%MACRO Do_vars; %Prithee my humble self = 1 %To 50; Var&i._line1 %PUT DOWN; %MEND Do_Vars;<\p>

Explanation: This macro working rule will energize a macro movable Do_vars, a la mode which vibration variables are generated with the paranymph pertinent to, cook loop. This programming avoids the time-consuming course of action re typing all the variables one by quantitive and the macro unrestrained that is generated can be used in VAR musical phrase to send for all the variables in the VAR statement. Here is an example in regard to invoking the macro variable name in VAR statement.<\p>

VAR %Do_Vars;<\p>

This above code seal generate complete VAR statement, internally invoking specific variable inbound the VAR statement, obverse as:<\p>

VAR Var1_line1 Var2_line1... Var50_Line1;<\p>

Where these variables are continuously generated by macro spotty that is present in the VAR statement, where this VAR statement utilizes these variables for generating customary values.<\p>

Running same procedure headed for a series of datasets:<\p>

In the previous examples, macros and loops will generate a set of variables in a datasets. Similarly to generate a series of dataset sable process steps programmer can bring into play the programming scramble as to macros and do walk to create injunction steps.<\p>

For example, there are series of SAS datasets like minus SAMPLE1 to SAMPLE10 that which contains student scores and programmer has to calculate the average score for per annum of 10 confirm datasets. So the following program will pull off the process on calculating the median score.<\p>

%MACRO Doing_MEAN; %DO the self = 1 %UPON 10; PROC MEANS DATA=Sample&i; VAR SCORE; MAGNUM OPUS "Average math score about Sample &i"; RUN; %END; %MEND Doing_MEAN;<\p>

Explanation: This macro named Doing_mean will be the case able to run in a dead circuit of 10, where congenitally doing a in no way procedure for each sample dataset.<\p>

DO_MEAN macro variable interiorly invokes any system at a forthwith, for 10 materials sets:<\p>

PROC MEANS DATA=Sample1; VAR SCORE; TITLE "Average math score of Sample 1"; RUN;<\p>

End: So one by one and every loop ambition generate a mean procedure, where taking the score flighty in the VAR statement and generating the average for each and every sample dataset. Where programmer pen generate one the pose fire escape at simon-pure cycle of indiction using macros and do loops.<\p>

Conclusion: The headmost purpose of using constructive programming inventory is to possibly avoid typing the repetitive inventory during programming. Therefore the program becomes more reusable.<\p>

[peterluo]

SAS Tips- Deal with Multi Ampersand

I came across a very interesting question a few days ago and I'd like to share with you.

Think about this program:

  %let one = two; %let two = three; %let three= four; %let four = five; %put &one;

  What is the output of this %put statement? Certainly it's two.

  Now we add one more ampersand.

  %let one = two; %let two = three; %let three= four; %let four = five; %put &&one;

  Would it be three this time? No. The output is still two.

  Why? Because SAS treats "&&" as "&". 

  But what should we do if we want to output "three"?

  Try this:

  %put &&&one;

  When SAS meets "&&&", it treats the first two ampersands as one, and holds them. The third ampersands combined with "one" make up a complete macro variable, which is resolved to "two". Then the held ampersand and "two" are further resolved to "three".

  If you understand this rule, no matter how many ampersands you meet, you could figure out the correct answer.

  Try "&&&&&&&one" and "&&&&&&&&&&one".

              The correct answers are "four" and "three". Did you get the right answers?

  Now we are able to give this chart, showing the most fundamental pattern hidden behind the rule.

    Do this until the number reaches zero. And the points you get is the times the macro variable gets resolved.

  For example, we have 7 "&". It is odd so minus 1, getting 1 point. Now we have 6, which is even so divide by 2, getting no points. Then we get 3, which is odd, so minus 1 and get 1 point. The last two steps is always the same: 2/2=1, 1-1=0. We get 3 points in total so the macro variable are going to be resolved for three times.

  one-two, two-three, three-four. OK, four is the answer.

  Moreover, you could also figure out in which way we can make it more times to resolve. That is the inverse process of the above calculation. Multiply the number by 2 and then plus 1. Like this 2(2(X+1)+1)+1.

[peterluo]

SAS Tips- Creating macro variables

We have many ways to create macro variables.

One of the most useful ways is %let statement. In proc sql, we often use "select into" to create a macro variable and assign a value to it. In data step, a common method is call symput routine. And the last, when define a macro, macro variables can be created by the defined macro parameters.

Here is a short presentation given by me, talking about different ways to create a macro variable.

So, just remember the 4 methods we mentioned.

%let statement

Inside a macro program

Select into in proc sql

Call symput in data step

Click here to view more presentations by liquidsilk

This blog is an attempt of using embedded video and power point. For more details and methods about creating macro variables, I recommend this paper:

Five Ways to Create Macro Variables: A Short Introduction to the Macro Language