第29行第18列的数组下标超出范围

Question

I was trying to use ARRAY function to do some calculation for a sample data set. The following is my code:

DATA INCHES;
SET SASHELP.FISH;
ARRAY CONVERT[5] HEIGHT WIDTH LENGTH1 LENGTH2 LENGTH3;
DO I = 1 TO 159;
CONVERT[I]=ROUND(CONVERT[I]/2.54);
DROP I;
END;
RUN;

And there was an error in the log:

ERROR: Array subscript out of range at line 29 column 18.

Thank you for your time and help.

Answer 1

Tom above is correct. Arrays allows you to perform calculations using the index, but they have the length. command

ARRAY CONVERT[5] HEIGHT WIDTH LENGTH1 LENGTH2 LENGTH3; 

Means convert[1] refers to Height ...[2] to width and so forth. As you mention only 5 variables, you can't refer to [6] as it does not exist.

Why use arrays? Well, you can do shorthand notations like sigma=sum (of convert[*])

DATA INCHES;
    SET SASHELP.FISH;
       ARRAY CONVERT[5] HEIGHT WIDTH LENGTH1 LENGTH2 LENGTH3;
        DO I = 1 TO 5;
            Converted[I]=ROUND(CONVERT[I]/2.54);
            DROP I;
        END;
RUN;

For more on Arrays see: https://support.sas.com/resources/papers/97529_Using_Arrays_in_SAS_Programming.pdf

Answer 2

Just to add to the previous comments, I notice that the dataset SASHELP.FISH has 159 records, so you seem to be confusing columns with rows.

A datastep will automatically loop through every record, unless explicitly told otherwise, therefore you do not need to set up such a loop.

The array you created stores the specified column values for the row the datastep is currently processing, therefore a loop set up to read these values cannot exceed the number of array elements (as mentioned by @Tom and @Pinegulf).

If you want to be sure of looping through all the values in the array, then you can use do i = 1 to dim(convert)