topic Re: Missing value for char in SAS Programming

Missing value for char

Ronein — Wed, 03 Jul 2019 08:48:09 GMT

Hello

As I know in SAS missing value for char is blank and missing value for numeric is period (.)

Why in this example missing value for char is also period (.)?

Why the value of the missing char is blank and not '.' ?

Data a;
Input X $ Y Z W;
cards;
M 56 68 89
F 33 60 .
M 45 91 .
. 35 65 .
;
run;

Re: Missing value for char

Kurt_Bremser — Wed, 03 Jul 2019 09:12:35 GMT

Because it's not a missing value. When reading character data into character variables, a dot is just a dot.

To correctly read empty data as missing character values, use the proper options in an infile statement, and deliver empty (non-existent) data:

data a;
infile cards dlm=' ' dsd truncover;
input X $ Y Z W;
cards;
M 56 68 89
F 33 60 .
M 45 91 .
 35 65 .
;
run;

A line starting with a delimiter is now considered to start with a missing value; without the dsd option, the delimiter would be discarded.

The truncover option is necessary to deal with trailing missing values.

Re: Missing value for char

gamotte — Wed, 03 Jul 2019 09:29:08 GMT

@Kurt_Bremser ,

I think the question concerns the fact that SAS reads the dot for X variable in the last

row of data as a missing value although X is a character variable. In the resulting dataset,

X=" " and not the string ".".

Re: Missing value for char

gamotte — Wed, 03 Jul 2019 09:39:14 GMT

@Tom gives an answer in the following thread (use the $char informat) :

https://communities.sas.com/t5/SAS-Programming/how-to-read-a-dot-or-fullstop-in-text-file/td-p/249234

Re: Missing value for char

Kurt_Bremser — Wed, 03 Jul 2019 09:41:17 GMT

You are right. That is a property of the default $w. informat, as mentioned in the relevant documentation:

The $w. informat trims leading blanks and left-aligns the values before storing the text. In addition, if a field contains only blanks and a single period, $w. converts the period to a blank because it interprets the period as a missing value. The $w. informat treats two or more periods in a field as character data.

Re: Missing value for char

gamotte — Wed, 03 Jul 2019 09:44:48 GMT

Maxim 1

Re: Missing value for char

Kurt_Bremser — Wed, 03 Jul 2019 09:46:20 GMT

@gamotte wrote:

Maxim 1

<Teal'c>Indeed</Teal'c>