long digit reading in sas - sas

I have a long ID number (say, 12184447992012111111). BY using proc import from csv file that number shortens itself with a addition of 'E' in between the digits (1.2184448E19, with format best12. and informat best32.). Browsing here I got to know the csv format itself shortens it previously so it is nothing to do with SAS. So I tried to copy say about 5 numbers and use datalines statement then also it results same.... It wil be helpful if anyone can suggest which format I need to use. Using best32. format I donot get the original number since most probably it modifies that altered number, which infact gives me 12184447992012111872 which is not my desired number.

Because your ID variable is really an identifier rather than a "real" number, you need to read it in as a character string. The value you show as an example is too large to be represented as an integer, so since SAS stores all numerics as floating point, you are losing "precision".
Since you mention using PROC IMPORT, copy the SAS program it generates and change the FORMAT and INFORMAT specifications from "21." and "best32." to "$32." (or whatever value matched your data.
Best of course would be if you had SAS Access to PC File formats, in which case you cound format the column as "text" in Excel and let SAS read it directly.

I'm not sure about the csv changing the value (they are just plain text files) - unless you are saving an excel spreadsheet as a csv file. If you are using excel just set the column to number format, no decimal places.
It might be easier to treat the column as text when importing it to SAS - unless you need to perform mathematical operations on it! If you really need to keep it as a number the format 32. should force it to be a 32 digit number - best is fairly sensibly changing it into scientific notation (though I suspect the data is there in the background and just displayed unhelpfully).

There is a SAS informat for reading exponential notation - Ew.d where w is the width and d the number of decimal places. In your case, it probably won't help because you will "lose" the complete number - and the value stored in case you read with this informat will be 1.2184448 * (10^19). The only way in your case is to ensure that the program which produces the CSV file outputs it in the right way. If you are creating the data from an Excel worksheet, then format the number in the Excel worksheet to display all the digits correctly.

Related

Reading a column with wide range of numbers and characters in sas

My dataset has a column with a wide range of values in it, such as the one below:
Value
3223145.306
1.044303129
345.556033
17693.00837
8.03E-06
NaN
1.97E-04
2.29E-04
8.01E-04
7.46E-04
18345.82237
47.78282804
4.14E-06
When I read this column in SAS, observations are read as character. Once I convert this to numeric the observations with E-04, E-05, E-06, etc. are being converted to 1.9736273 instead of 0.00019736273.
How do I account for E-04, E-05, E-05 etc.?
code for character to numeric:
Value=input(Value, best12.);
You have to make a NEW variable if you want it to have a different type.
The INPUT function does not care if the width used on the informat is larger than the length of the string being read. So just use the maximum width that the informat supports. Also BEST is the name of a FORMAT, not an INFORMAT. If you use as the name of an informat then SAS will just default to using the normal numeric informat. So just go ahead and say that from the start instead of confusing format names for informat names.
The normal numeric informat can read those strings as numbers. So this code will work to create a new numeric variable named NUMBER from the existing character variable named VALUE.
number = input(VALUE,32.);
The only string in your list that will cause any issues is the string 'NaN'. SAS will not know how to translate that so you will just get a missing value as the result. Which is basically what systems that use that "not a number" symbol mean by it anyway. To prevent the notes in the log you can either test for it explicitly.
if upcase(value) not in ('NA','N/A','NAN') then number=input(value,32.);
Or just suppress the error messages by add the ?? modifier.
number=input(value,??32.);
But then you will not get any message if there is other gibberish in the value variable.

SAS Input: Dollar Amounts in Billions

I have an input file with a lot of dollar amounts given like this:
$433.5B $41.1B $331.1B $407.4B
$110.8B $19B $2,265.8B $170.1B
where the 'B' character stands for "billions". I do not have other suffixes like M or k. I need to read in this file using an INPUT statement in SAS inside a DATA step, and these figures should be numerics. There are several challenges to overcome, as well as a couple of features of the data to note:
There are dollar signs everywhere.
Some of the numbers have decimal points, and some don't, so we're dealing with variable-length data.
There are commas inside the numbers, such as $2,265.8B.
The most pesky aspect of this data are the B's after each amount.
The B's are always in the same columns.
What informat should I use to read in this numerical data?
I thought of using something along the lines of :DOLLAR4.1, like this:
Data bigcompanies;
Infile 'path\bigcompanies.dat' MISSOVER;
Input (sales profits assets market_value) (:DOLLAR4.1);
Run;
but it gives me nothing (as in, I get periods for those numbers). I don't know how to handle the B, which is, I think, the crux of the problem. The SAS documentation on the DOLLAR informat is rather sparse, unfortunately.
Many thanks for your help!
If the data is in fixed columns then just skip the columns where the B appears.
data test;
input sales dollar6. +1 profits dollar8. +1 assets dollar9. +1 market_value dollar9. +1 ;
*---+---10----+---20----+---30----+---40 ;
cards;
$433.5B $41.1B $331.1B $407.4B
$110.8B $19B $2,265.8B $170.1B
;
proc print;
run;
Results
market_
Obs sales profits assets value
1 433.5 41.1 331.1 407.4
2 110.8 19.0 2265.8 170.1
Note that you normally never want to add a decimal part to an informat. That is telling SAS where to place the decimal point when it does not appear in the source text. So "integers" will be divided by that power of 10.

How to keep single quote when importing Excel data to SAS

I am importing an Excel spreadsheet into SAS using Proc Import:
Proc Import out=OUTPUT
Datafile = "(filename)"
DBMS=XLSX Replace;
Range = "Sheet1$A:Z";
run;
My numeric data columns contain a mixture of values held in Excel as numerics and '0 values held as text - i.e. with a leading apostrophe / single quote. When SAS imports these it treats them all the same (i.e. it returns Character strings of the values with the leading apostrophe stripped out).
This results in differences from the spreadsheet when calculations are applied (e.g. averaging) as Excel treats the '0 values as missing but SAS treats them as 0.
Is it possible to import the values as strings including the leading single quote / apostrophe, so that I can replace the '0 with missing values but keep the 0 records as 0? I would like to avoid having to manually manipulate the data in Excel as this data is drawn from an external source (don't ask...)
I doubt it. I think Excel doesn’t really consider the leading apostrophe as part of the value. It’s just a crazy way to indicate that a value is a text string (rather than numeric). When SAS imports the data, it recognizes that the quote is not part of the value. So if you’ve got an Excel column with ‘0 in some cells and 0 in others, it’s going to come in as character, and I don’t think you can tell the difference between them.
Unfortunately, the xlsx engine doesn’t support the s DBSASTYPE option. Other engines that import Excel have the DBSASTYPE option. That should allow you to tell SAS to import a column as a numeric variable, even if it sees character values. If it’s the case that you want all text values in the cell converted to missing, that might do the trick. But it’s possible it would still treat ‘0 the same as 0. I’m away from SAS, so can’t test.
Option:
The ~ (tilde) format modifier enables you to read and retain single quotation marks.
http://support.sas.com/documentation/cdl/en/lrcon/62955/HTML/default/viewer.htm#a003209907.htm
Is it possible to convert the .xlsx to .txt keeping the single quotes? Because it is not possible to infile xlsx in a data step.
filename df disk 'C:\data_temp\ex.txt';
data test;
infile df firstobs=2;
input ID $2. x ~$3. ;
run;
proc print data=test;
run;

SAS Numeric Informat vs Length

I'm trying to determine how SAS is reading the length statement and then the informat statement. I could be misunderstanding, but I'm under the impression that the informat statement for numeric variables worked like this:
informat number 5.;
This would give the variable number the informat 5, allowing 5 numbers to fill it. E.G. 12345
However, when I run the below program, I have a number that has 9 digits, 987654321, with the appropriate length to fit the digits, 6, which will represent all numbers up to 137,438,953,472
Q: is length statement 'overriding' the informat statement and allowing all 9 digits to fill the variable number? How are all 9 digits able to fit in the variable number with an informat of 5.?
data tst;
input number;
length number 6;
informat number 5.;
datalines;
987654321
;
run;
proc print data=tst;
run;
Based on this SAS documentation:
http://support.sas.com/documentation/cdl/en/lrdict/64316/HTML/default/viewer.htm#a000199348.htm
w specifies the width of the input field. Range: 1-32
It would seem that the informat w.d would work as I first described and not allow all 9 digits to fill number
Because you are using list mode input. In that situation SAS reads the next word, however long it is. Essentially in list mode input (including when using the : modifier before an informat specified in the input statement) the width on a informat is ignored.
Other than for creating metadata in the SAS dataset there is not much value in attaching informats like 5. or $10. to variables.
SAS does not need them to understand how to convert text into values, unlike informats like date..
In list mode it ignores the width part.
And in formatted input, where the width matters, you have to specify the informat in the INPUT statement itself.
First off: length is not overriding, or having any impact on, the informat or the read-in. length solely describes how many bytes are used to store the number, nothing more.
For numeric variables, informats don't work quite the intuitive way. I'm not sure why - but they don't.
See this quotation from the list input documentation:
For a character variable, this format modifier reads the value from the next non-blank column until the pointer reaches the next blank column, the defined length of the variable, or the end of the data line, whichever comes first. For a numeric variable, this format modifier reads the value from the next non-blank column until the pointer reaches the next blank column or the end of the data line, whichever comes first.
They do listen to the informat to some extent - add a .2 there and you'll get a forced decimal - but they don't listen to it as to how long of a value to read in. I'm not sure why; it seems intuitive that they should, but they don't.
Here's it with character variables - they respect the length but also ignore the informat:
data tst;
length number $9;
informat number $5.;
input number;
datalines;
987654321
;
run;
proc print data=tst;
run;
Though you do need to put the informat before the input statement (and the length for numeric variables).
More detail is available on the documentation page for INFORMAT:
How SAS Treats Variables When You Assign Informats with the INFORMAT Statement
Informats that are associated with variables by using the INFORMAT statement behave like informats that are used with modified list input. SAS reads the variables by using the scanning feature of list input, but applies the informat.
In modified list input, SAS
does not use the value of w in an informat to specify column positions or input field widths in an external file
uses the value of w in an informat to specify the length of previously undefined character variables
ignores the value of w in numeric informats
uses the value of d in an informat in the same way it usually does for numeric informats
treats blanks that are embedded as input data as delimiters unless you change their status with a DLM= or DLMSTR= option specification in an INFILE statement.
That is much more explicit about the fact that SAS ignores the value of w.
The length of a variable defines the amount of space the value occupies when stored to disk. NOTE: During a running DATA step all numerics are double precision, the truncation to a length < 8 only occurs during output media.
The informat is a separate concept from the length. Informat defines how incoming value representations are to be interpreted for storage as a SAS numeric value. Incoming value representations would be what ever text has to be processed; be it a INPUT statement reading a file, a VIEWTABLE field edit processing a typed in value, an EG grid cell edit, etc...
The format is similarly separate concept that defines how SAS renders a numeric value for output; be it a PUT statement, a VIEWTABLE row render, a placement in a PROCs output, an EG grid cell, etc...
Explanation
Now that that is out of the way, The informat is honored when explicitly stated in an INPUT statement:
data _null_;
attrib number length=6 informat=5.;
input number 5.;
put 'NOTE: ' number=;
datalines;
987654321
run;
===== LOG =====
NOTE: number=98765
And, as you question, the variables associated informat is not applied an explicit numeric informat is not stated
data _null_;
attrib number length=6 informat=5.;
input number;
put 'NOTE: ' number=;
datalines;
987654321
run;
===== LOG =====
NOTE: number=987654321
So the first is LIST input with format specified and the second is a simple LIST input (because no format is specified).
Simple list input will accept some absurdly large data, and the resultant value, while not tail-end precise, will be at the correct exponential level.
data _null_;
attrib number length=6 informat=5.;
input number;
put 'NOTE: ' number= ;
datalines;
123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890
run;
===== LOG =====
NOTE: number=1.2345679E89
What do the docs for INPUT Statement, List say ? Certainly nothing about using the variables declared informat when none indicated
Simple List Input
Simple list input places several restrictions on the type of data that
the INPUT statement can read:
• By default, at least one blank must separate the input values. Use
the DLM= or DLMSTR= option or the DSD option in the INFILE statement
to specify a delimiter other than a blank.
• Represent each missing value with a period, not a blank, or two
adjacent delimiters.
• Character input values cannot be longer than 8 bytes unless the
variable is given a longer length in an earlier LENGTH, ATTRIB, or
INFORMAT statement.
• Character values cannot contain embedded blanks unless you change
the delimiter.
• Data must be in standard numeric or character format. (footnote 1)
FOOTNOTE 1: See SAS Language Reference: Concepts for the information about standard and nonstandard data values. (my LOL)
The concepts for "SAS Variable Attributes" states
informat
refers to the instructions that SAS uses when reading data values. If
no informat is specified, the default informat is w.d for a numeric
variable, and $w. for a character variable. You can assign SAS
informats to a variable in the INFORMAT or ATTRIB statement. You can
use the FORMAT procedure to create your own informat for a variable.
(my bold)
Apparently there is no explicit default such as 32. or best32. because values with more than 32 digits will be inputted without error.
So does the documentation explain things ? Yea, well, sorta. What are the take aways:
The human intuition of a numeric variable inheriting its informat during simple list input does not align with the actual implemented behavior.
Tectonic amounts of existing SAS code means a change to implement this intuition is highly unlikely
Simple statements can involve a lot of concepts with wide ranging documentation
Possible change is that the documentation will be updated to be more explicit about the simple list input caveats

Convert Scientific notation to text or integer using regex in Notepad++

I am looking to convert a scientific notation number into the full integer number.
E.g:
8.18234E+11 => 818234011668
Excel reformatted all my upc codes within a csv and this solution is not working for me.
I have my csv open in Notepad++ and would love to do this using a regex find and replace.
Thanks.
The damage is already done and cannot be recovered from the CSV file. 8.18234E+11 could be anything* from 818233500000 to 818234499999.
To prevent Excel from rounding large numbers, you need to store them as text. If you set the cell format to text, any value inserted from then on should be automatically interpreted as text. In OpenOffice Calc (I don't have MS Excel), you can also prefix a numeric value with ' to get it interpreted as text no matter the cell format.
There is a chance that the correct value is stored in the original XLS (or XSLX or ODS or the live Excel session or ...) file. If not, then you'll have to enter the data again. If the data is there, you need to store it as text or increase the number of significant digits in the exported CSV. If you only have the exported data, then you're out of luck.
*UPC has a single check digit, so only 100 000 out of the 1 000 000 codes are actually valid UPC codes.