topic Re: Dx.p format - in SAS Programming

Dx.p format -

AndrewHowell — Wed, 02 Oct 2019 14:22:41 GMT

Trying to make sense of the "D" numeric format, and when best to use it.

And why a "put(12345,D32.9)" yields " 12345.0000000000000000" (16 zeroes)?

Why use D32.9 when I could use 32.16?

The documentation seems a bit hard to decypher (summary below).

Any assistance appreciated - use cases, perhaps?

Dx.p format - SAS(R) 9.4 Formats and Informats: Reference

Prints numeric values, possibly with a great range of values, lining up decimal places for values of similar magnitude.

Details - The Dw.p format writes numbers so that the decimal point aligns in groups of values with similar magnitude. Larger values of p print the data values with more precision and potentially more shifts in the decimal point alignment. Smaller values of p print the data values with less precision and a greater chance of decimal point alignment.

Comparisons

The BESTw. format writes as many significant digits as possible in the output field, but if the numbers vary in magnitude, the decimal points do not line up.
Dw.p writes numbers with the desired precision and more alignment than the BESTw format.
The BESTDw.p format is a combination of the BESTw. format and the Dw.p format in that it formats all numeric data, and it does a better job of aligning decimals than the BESTw. format.
The w.d format aligns decimal points, if possible, but it does not necessarily show the same precision for all numbers.

Re: Dx.p format -

ChrisNZ — Thu, 03 Oct 2019 03:40:20 GMT

The same code yields 19 zeros for me.

%put &=sysscpl &=sysvlong %sysfunc(putn(12345,D32.9));
SYSSCPL=X64_SRV12 SYSVLONG=9.04.01M2P072314 12345.0000000000000000000

Re: Dx.p format -

AndrewHowell — Thu, 03 Oct 2019 09:45:10 GMT

@ChrisNZ,

I've tried 32.0 up to 32.9 (32.0 is same as 32.3). The result is still MORE decimals than

So I guess I'm looking for clear documentation on what the "D" format is actually FOR, and how to know - with certainty - what the output would be for various values of width and/or decimal.

Background: I'm storing the result in strings, and I need to know the length of the strings and the placement of the decimal point.

Re: Dx.p format -

ChrisNZ — Thu, 03 Oct 2019 21:34:17 GMT

> I need to know the length of the strings and the placement of the decimal point.

Why use format Dw.p then?

Its description

Prints numeric values, possibly with a great range of values, lining up decimal places for values of similar magnitude.

is enticing for your purpose, but the small-print caveat

Smaller values of p print the data values with less precision and a greater chance of decimal point alignment.

includes the word chance, which is not what you seem to want.

A fixed format like w.d seems more suitable for your purpose, doesn't it?

I never used format Dw.p before, so am unsure how precision parameter works. As you rightly point out, the documentation is rather terse on the matter.