I use an ODBC table handler to read data from Excel and CSV files into an AMPL model. But the thing I encountered probably doesn't have much to do with the precise programs and programming language I use.
Among the data are two specific types of strings: three-digit alphabetic and six-digit alphanumeric.
When the three-digit alphabetic type includes a NAN string, AMPL throws an error. As I found out, the reason is that it understands NAN as "NaN" (not a number). It cannot use this as an index.
The six-digit alphanumeric type sometimes include strings like 3E1234. This seems to be a problem because AMPL (or the handler) understands this as a number in scientific notation. So it reads 3*10^1234, which is handled as infinity. So when there is one 3E1234 entry and one 3E1235 entry, it sees them both as infinity.
I understand these two. And although they are annoying, I can work with that. Now I encountered that a string SK1234 is parsed as the number 1234. I have learned a bit of programming in college, but I don't have any idea why this happens. Is the prefix SK anything special?
EDIT: Here is an example that reproduces the error:
The model file:
set INDEX;
param value;
The "run" file:
table Table1 IN "tableproxy" "odbc" "DSN=NDE" "Test.csv": INDEX <- [Index], value ~ Value;
read table Table1;
NDE is a user DSN that uses the Microsoft Text Driver in the appropriate folder.
And the CSV file:
Index,Value
SK1202,1
SK1445,2
SK0124,3
SK7896,4
SK1,5
AB1234,6
After running all this code, I type display INDEX and get
set INDEX := 1202 1445 124 7896 1 Missing;
So the field Index is treated as a numeric field with the first five entries converted to a number. The last entry cannot be converted so it is treated as Missing.
The DSN's setting is that it sets the type according to the first 25 lines. For some reason, it understands the SK... entries as numbers and therefore reads all as numbers.
For the Text ODBC driver to detect column type correctly, values should be quoted:
Index,Value
'SK1202',1
'SK1445',2
'SK0124',3
'SK7896',4
'SK1',5
'AB1234',6
Related
I've been looking for a good way to see if a string of items are all numbers, and thought there might be a way of specifying a range from 0 to 9 and seeing if they're included in the string, but all that I've looked up online has really confused me.
def validate_pin(pin)
(pin.length == 4 || pin.length == 6) && pin.count("0-9") == pin.length
end
The code above is someone else's work and I've been trying to identify how it works. It's a pin checker - takes in a set of characters and ensures the string is either 4 or 6 digits and all numbers - but how does the range work?
When I did this problem I tried to use to_a? Integer and a bunch of other things including ranges such as (0..9) and ("0..9) and ("0".."9") to validate a character is an integer. When I saw ("0-9) it confused the heck out of me, and half an hour of googling and youtube has only left me with regex tutorials (which I'm interested in, but currently just trying to get the basics down)
So to sum this up, my goal is to understand a more semantic/concise way to identify if a character is an integer. Whatever is the simplest way. All and any feedback is welcome. I am a new rubyist and trying to get down my fundamentals. Thank You.
Regex really is the right way to do this. It's specifically for testing patterns in strings. This is how you'd test "do all characters in this string fall in the range of characters 0-9?":
pin.match(/\A[0-9]+\z/)
This regex says "Does this string start and end with at least one of the characters 0-9, with nothing else in between?" - the \A and \z are start-of-string and end-of-string matchers, and the [0-9]+ matches any one or more of any character in that range.
You could even do your entire check in one line of regex:
pin.match(/\A([0-9]{4}|[0-9]{6})\z/)
Which says "Does this string consist of the characters 0-9 repeated exactly 4 times, or the characters 0-9, repeated exactly 6 times?"
Ruby's String#count method does something similar to this, though it just counts the number of occurrences of the characters passed, and it uses something similar to regex ranges to allow you to specify character ranges.
The sequence c1-c2 means all characters between c1 and c2.
Thus, it expands the parameter "0-9" into the list of characters "0123456789", and then it tests how many of the characters in the string match that list of characters.
This will work to verify that a certain number of numbers exist in the string, and the length checks let you implicitly test that no other characters exist in the string. However, regexes let you assert that directly, by ensuring that the whole string matches a given pattern, including length constraints.
Count everything non-digit in pin and check if this count is zero:
pin.count("^0-9").zero?
Since you seem to be looking for answers outside regex and since Chris already spelled out how the count method was being implemented in the example above, I'll try to add one more idea for testing whether a string is an Integer or not:
pin.to_i.to_s == pin
What we're doing is converting the string to an integer, converting that result back to a string, and then testing to see if anything changed during the process. If the result is =>true, then you know nothing changed during the conversion to an integer and therefore the string is only an Integer.
EDIT:
The example above only works if the entire string is an Integer and won’t properly deal with leading zeros. If you want to check to make sure each and every character is an Integer then do something like this instead:
pin.prepend(“1”).to_i.to_s(1..-1) == pin
Part of the question seems to be exactly HOW the following portion of code is doing its job:
pin.count("0-9")
This piece of the code is simply returning a count of how many instances of the numbers 0 through 9 exist in the string. That's only one piece of the relevant section of code though. You need to look at the rest of the line to make sense of it:
pin.count("0-9") == pin.length
The first part counts how many instances then the second part compares that to the length of the string. If they are equal (==) then that means every character in the string is an Integer.
Sometimes negation can be used to advantage:
!pin.match?(/\D/) && [4,6].include?(pin.length)
pin.match?(/\D/) returns true if the string contains a character other than a digit (matching /\D/), in which case it it would be negated to false.
One advantage of using negation here is that if the string contains a character other than a digit pin.match?(/\D/) would return true as soon as a non-digit is found, as opposed to methods that examine all the characters in the string.
I am trying to save a numeric-with-decimal-places(f8.6) variable from an SPSS file into a fixed ASCII file. The goal is to write it into certain columns of the ASCII (21 to 30).
WRITE OUTFILE='C:\misc\ascii.dat'
ENCODING='UTF8'
TABLE /1
variable 21-30.
exe.
writes to the correct positions, but not with decimals.
variable 21-30 (f)
does the same thing.
variable (f8.6)
saves with decimals, but on positions 1 to 10.
variable 21-30 (f8.6)
results in an error, because apparently you cannot specify both columns and format.
I know two workarounds, but both involve additional data editing, which I'd rather not do:
Convert variable to string and save it as string - but I am not sure about the implications (encoding, decimal places, or whatever other thing I am not even considering)
add an empty string variable with length of 20 before my variable.
But is there a straightforward way of doing this, without workarounds ?
You can add the 20 spaces in the command itself, like this:
WRITE OUTFILE='C:\misc\ascii.dat'
ENCODING='UTF8'
TABLE / ' ' YourNumVar (f8.6) .
exe.
I am trying to use the "food_descriptions" fixture in a "minitest" test in Rails 4 beta1:
butter:
NDB_No: "01001"
FdGrp_Cd: "0100"
Long_Desc: "Butter, salted"
The test I have is this:
it "must work" do
food_descriptions(:butter).NDB_No.must_equal "01001"
end
However, when I run the test I get this error: Expected: "01001" Actual: 1001
I don't understand why that number is not recognized as a string. I've read that yml treats values that start with 0 as octal values, so adding the quotes should be enough to treat it as a string but is not working. I have also try the pipe "|" sign but doesn't work either.
Any idea why?
Quick Answer (TL;DR)
YAML 1.2 leading zeros can be preserved by quoting a scalar value.
Context
YAML 1.2
Scalar value with leading zeros
Problem
Scenario: Developer wishes to specify a scalar value with leading zero in a YAML 1.2 file.
When parsed, the leading zero gets omitted or truncated
Solution
Quote a scalar value in YAML to have it parsed as a string.
Leading zeros are preserved for non-numeric values.
Pitfalls
Data type casting for databases or programming language context may convert string scalar to numeric scalar value.
It turns out the problem is not what I thought it was (yml). The problem was that the fixtures were being pushed to the DB and the tests were actually retrieving the entry from the database (I thought the fixture were just in memory), and the database column type for that value was integer, not string, thus the leading zeros were being removed. My real problem was that I wanted that column to be the primary key of the table of type string and I didn't realize that the migration I created didn't change the type of the column to string in the test database.
I'm running some tests on Cobol pictures and wondering if --- is a valid picture. Am I right in saying that this picture accepts values in the range of -99 through to +99. If it is valid then it is possible for the picture to accept 3 spaces as a value?
For example:
12 would return 12
1 would return 1
Cheers
Yes --- is a valid PICTURE clause. The variable corresponding to this PICTURE will accept assignments of numeric values in the range -99 through to +99. It cannot be assigned non-numerics (space for example). However, if you were to DISPLAY this variable after assigning a numeric value to it, leading zeros will be replaced by spaces. Consequently, if you MOVE ZERO to this item it will DISPLAY only spaces. Attempting to MOVE SPACES to this item will result in a compile error (incompatible data types). This last bit may seem a little counter intutive, but remember that this type of PICTURE clause implies a USAGE of display - basically items defined in this manner are used to 'pretty print' numbers. About the only operations you can preform with USAGE DISPLAY items is MOVE to or from and DISPLAY them.
EDIT - Response to Comment
A PICTURE of ---X(2) is invalid. The chart below illustrates combinations and the order that symbols may appear in a PICTURE string. Notice that parenthesis are not in the chart. Logically you can replace them with the corresponding number of occurences of the preceding character before reading the string. For example X(3) is read as XXX. If you really want to parse out a PICTURE string properly, you can use this chart to construct a BNF grammar specifically for them.
If this is a numeric picture, it won't accept spaces.
I have some csv record which are variable in length , for example:
0005464560,45667759,ZAMTR,!To ACC 12345678,DR,79.85
0006786565,34567899,ZAMTR,!To ACC 26575443,DR,1000
I need to seperate each of these fields and I need the last field which should be a money.
However, as I read the file, and unstring the record into fields, I found that the last field contain junk value at the end of itself. The amount(money) field should be 8 characters, 5 digit at the front, 1 dot, 2 digit at the end. The values from the input could be any value such as 13.5, 1000 and 354.23 .
"FILE SECTION"
FD INPUT_FILE.
01 INPUT_REC PIC X(66).
"WORKING STORAGE SECTion"
01 WS_INPUT_REC PIC X(66).
01 WS_AMOUNT_NUM PIC 9(5).9(2).
01 WS_AMOUNT_TXT PIC X(8).
"MAIN SECTION"
UNSTRING INPUT_REC DELIMITED BY ","
INTO WS_ID_1, WS_ID_2, WS_CODE, WS_DESCRIPTION, WS_FLAG, WS_AMOUNT_TXT
MOVE WS_AMOUNT_TXT(1:8) TO WS_AMOUNT_NUM(1:8)
DISPLAY WS_AMOUNT_NUM
From the display, the value is rather normal: 345.23, 1000, just as what are, however, after I wrote the field into a file, here is what they become:
79.85^M^#^#
137.35^M^#
I have inspect the field WS_AMOUNT_NUM, which came from the field WS_AMOUNT_TXT, and found that ^# is a kind of LOW-VALUE. However, I cannot find what is ^M, it is not a space, not a high-value.
I am guessing, but it looks like you may be reading variable length records from a file into a fixed length
COBOL record. The junk
at the end of the COBOL record is giving you some grief. Hard to say how consistent that junk is going
to be from one read to the next (data beyond the bounds of actual input record length are technically
undefined). That junk ends up
being included in WS_AMOUNT_TXT after the UNSTRING
There are a number of ways to solve this problem. The suggestion I am giving you here may not
be optimal, but it is simple and should get the job done.
The last INTO field, WS_AMOUNT_TXT, in your UNSTRING statement is the one that receives all of the trailing
junk. That junk needs to be stripped off. Knowing that the only valid characters in the last field are
digits and the decimal character, you could clean it up as follows:
PERFORM VARYING WS_I FROM LENGTH OF WS_AMOUNT_TXT BY -1
UNTIL WS_I = ZERO
IF WS_AMOUNT_TXT(WS_I:1) IS NUMERIC OR
WS_AMOUNT_TXT(WS_I:1) = '.'
MOVE ZERO TO WS_I
ELSE
MOVE SPACE TO WS_AMOUNT_TXT(WS_I:1)
END-IF
END-PERFORM
The basic idea in the above code is to scan from the end of the last UNSTRING output field
to the beginning replacing anything that is not a valid digit or decimal point with a space.
Once a valid digit/decimal is found, exit the loop on the assumption that the rest will
be valid.
After cleanup use the intrinsic function NUMVAL as outlined in my answer to your
previous question
to convert WS_AMOUNT_TXT into a numeric data type.
One final piece of advice, MOVE SPACES TO INPUT_REC before each READ to blow away data left over
from a previous read that might be left in the buffer. This will protect you when reading a very "short"
record after a "long" one - otherwise you may trip over data left over from the previous read.
Hope this helps.
EDIT Just noticed this answer to your question about reading variable length files. Using a variable length input record is a better approach. Given the
actual input record length you can do something like:
UNSTRING INPUT_REC(1:REC_LEN) INTO...
Where REC_LEN is the variable specified after OCCURS DEPENDING ON for the INPUT_REC file FD. All the junk you are encountering occurs after the end of the record as defined by REC_LEN. Using reference modification as illustrated above trims it off before UNSTRING does its work to separate out the individual data fields.
EDIT 2:
Cannot use reference modification with UNSTRING. Darn... It is possible with some other COBOL dialects but not with OpenVMS COBOL. Try the following:
MOVE INPUT_REC(1:REC_LEN) TO WS_BUFFER
UNSTRING WS_BUFFER INTO...
Where WS_BUFFER is a working storage PIC X variable long enough to hold the longest input record. When you MOVE a short alpha-numeric field to a longer one, the destination field is left justified with spaces used to pad remaining space (ie. WS_BUFFER). Since leading and trailing spaces are acceptable to the NUMVAL fucnction you have exactly what you need.
I have a reason for pushing you in this direction. Any junk that ends up at the trailing end of a record buffer when reading a short record is undefined. There is a possibility that some of that junk just might end up being a digit or a decimal point. Should this occur, the cleanup routine I originally suggested would fail.
EDIT 3:
There are no ^# in the resulting WS_AMOUNT_TXT, but still there are a ^M
Looks like the file system is treating <CR> (that ^M thing) at the end of each record as data.
If the file you are reading came from a Windows platform and you are now
reading it on a UNIX platform that would explain the problem. Under Windows records
are terminated with <CR><LF> while on UNIX they are terminated with <LF> only. The
UNIX file system treats <CR> as if it were part of the record.
If this is the case, you can be pretty sure that there will be a single <CR> at the
end of every record read. There are a number of ways to deal with this:
Method 1: As you already noted, pre-edit the file using Notepad++ or some other
tool to remove the <CR> characters before processing through your COBOL program.
Personally I don't think this is the best way of going about it. I prefer to use a COBOL
only solution since it involves fewer processing steps.
Method 2: Trim the last character from each input record before processing it. The last
character should always be <CR>. Try the following if you
are reading records as variable length and have the actual input record length available.
SUBTRACT 1 FROM REC_LEN
MOVE INPUT_REC(1:REC_LEN) TO WS_BUFFER
UNSTRING WS_BUFFER INTO...
Method 3: Treat <CR> as a delimiter when UNSTRINGing as follows:
UNSTRING INPUT_REC DELIMITED BY "," OR x"0D"
INTO WS_ID_1, WS_ID_2, WS_CODE, WS_DESCRIPTION, WS_FLAG, WS_AMOUNT_TXT
Method 4: Condition the last receiving field from UNSTRING by replacing trailing
non digit/non decimal point characters with spaces. I outlined this solution a litte earlier in this
question. You could also explore the INSPECT statement using the REPLACING option (Format 2). This should be able to do pretty much the same thing - just replace all x"00" by SPACE and x"0D" by SPACE.
Where there is a will, there is a way. Any of the above solutions should work for you. Choose the one you are most comfortable with.
^M is a carriage return.
Would Google Refine be useful for rectifying this data?