topic Re: Avg of an array in SAS Programming

Avg of an array

MattLin — Tue, 13 Aug 2013 13:43:32 GMT

Dear All,

I need the average of 1000 values as the last column.

X y1 y2 ... y1000 AVG

a [ 1000 simulations result] Here is the avg of 1000 values

I have not even started the simulation, but I imagine I will use

array sim{1000} y;

Thank you.

- Matt

Re: Avg of an array

RichardinOz — Tue, 13 Aug 2013 13:52:01 GMT

You do not need an array

AVG = mean (of y1 -- y1000) ;

Richard

Re: Avg of an array

MattLin — Tue, 13 Aug 2013 14:12:29 GMT

Thanks Richard !!!

So if I use array, then is this correct?

AVG = mean(of sim{1} - sim{1000} );

Side question, what is the difference b/w one dash - and two dashes -- ?

Thanks.

- Matt

Re: Avg of an array

Jagadishkatam — Tue, 13 Aug 2013 14:23:00 GMT

if we consider that there are variables like below

y1 y2 y3..............y1000

then we can take the average of all these variable in the below way

average=mean(of y1-y1000);

This way we will get the average of all the 1000 variables into one variable.

Thanks,

Jagadish

Re: Avg of an array

Jagadishkatam — Tue, 13 Aug 2013 14:30:50 GMT

Another approach of using arrays to get the means of the variables is as below

array avg(*) y1-y1000;

average=mean(of avg(*));

Thanks,

jagadish

Re: Avg of an array

Astounding — Tue, 13 Aug 2013 17:08:20 GMT

Regarding the side question ...

A single dash would be preferred here. It refers to the list of variables that have the same prefix, with a numeric suffix.

The double dash also refers to a list of variables, but the name pattern does not matter. This is a legitimate list:

cat -- dog

It means all the variables in the data set, in the order in which they were created, starting with CAT and ending with DOG. If you are not sure of the internal order of variables, PROC CONTENTS will tell you. It can even print its report using the internal order rather than the alphabetical order.

Re: Avg of an array

RichardinOz — Thu, 15 Aug 2013 00:58:47 GMT

The choice of a double dash in my response was deliberate, in case the O/P had simplified (as is often the case) the names of the variables and they were not a numerical sequence. It would give exactly the same results unless for some reason another variable was created mid sequence, which in this instance seemed unlikely.

Richard