Fortran to SAS code conversiton - fortran

Question

I want to create 1, 2, 3 dimensional variables/arrays inside of proc iml. My code looks following:
proc iml;
start Mean1(x); /*this is 1 dimension variable/array*/
Mean1(x)=sum(x)/dim(x);
finish;
proc iml;
start Mean2(x); /*this is 2 dimension variable/array*/
Mean1(x)=sum(x)/dim(x);
finish;
proc iml;
start Mean3(x); /*this is 3 dimension variable/array*/
Mean1(x)=sum(x)/dim(x);
finish;
I tried to do like this:
proc iml;
declare double x[dim(n),dim(n)];
start Mean2(x); /*this is 2 dimension variable or array*/
Mean1(x)=sum(x)/dim(a, x);
finish;
But it's not working. Could you help me?

Answer 1

There are a few things to know here.
SAS IML arrays are 1 indexed C style row major arrays. Not column
major like Fortran.
To my knowledge, there are no 3 dimensional arrays in IML. Always possible I am mistaken.
All numbers in SAS are doubles.
IML has nice reduction operators that make means easy
and very fast.
To declare a matrix/array, use the J(nrow,ncol,fill) function:
proc iml;
x = J(10,5,1); /*Declare a 10x5 matrix filled with 1s*/
x = normal(x); /*Fills matrix X with random numbers, uses the values in X as the seed*/
mean_all = x[:]; /*mean over all values in x*/
mean_col = x[:,];/*mean of each column */
mean_row = x[,:];/*mean of each row */
print mean_all;
print mean_col;
print mean_row;
quit;
I highly recommend going through the IML documentation. http://support.sas.com/documentation/onlinedoc/iml/index.html