Batch File: Reading Floating Point Values from a .csv file - csv

Question

I have made a batch file that reads a .csv file. It then proceeds to take the values from a specific column (in this case, the 4th) and find the highest value. The script works perfectly fine with whole numbers, but once I attempt to pass in a .csv file featuring floating point numbers, the script only reads the first number. ie, 1.546 = 1, 0.896 = 0, etc...
How do I read the floating points normally? In this case, at least 2 points of precision (though the values can be up to 6 points of precision with the real .csv file)
One other thing to note is that this prints out "missing operator" 3 times. I THINK this may be due to spacing, but am not sure where.
The script is as follows:
#echo off
set cur=0
set max=0
for /f "usebackq tokens=1-4 delims=," %%a in ("sample.csv") do (call :func "%%d")
echo Max is %max%
goto :here
:func
set /a cur=%1
if %cur% gtr %max% (set /a max=%cur%)
goto :eof
:here
pause
This is sample.csv, which works fine:
1,2,,3,3,5,,
5,6,,7,12.3,6,,
9,10,,11,11.4,7,,
13,14,,15,10.1,2,,
I threw in some additional commas, just to test the code.

Answer 1

If you were to do actual calculations, then I would not recommend batch-file for this while using fractions, but to simply test the highest value, we can split the string by . match either side. You can still not use set /a to make it an actual integer though:
#echo off & setlocal enabledelayedexpansion
set num=0 & set frac=0
for /f "usebackq tokens=1-4 delims=," %%a in ("sample.csv") do (
for /f "tokens=1* delims=." %%i in ("%%~d") do (
if not "%%j" == "" if %%i gtr !num! (
set "num=%%i"
set "max=%%~d"
)
if %%i geq !num! if %%~j gtr !frac! (
set "frac=%%~j"
set "max=%%~d"
)
)
)
echo Max is %max%
pause
As per your comment on ~ here is an extract from for /?
In addition, substitution of FOR variable references has been enhanced.
You can now use the following optional syntax:
%~I - expands %I removing any surrounding quotes (")
%~fI - expands %I to a fully qualified path name
%~dI - expands %I to a drive letter only
%~pI - expands %I to a path only
%~nI - expands %I to a file name only
%~xI - expands %I to a file extension only
%~sI - expanded path contains short names only
%~aI - expands %I to file attributes of file
%~tI - expands %I to date/time of file
%~zI - expands %I to size of file
%~$PATH:I - searches the directories listed in the PATH
environment variable and expands %I to the
fully qualified name of the first one found.
If the environment variable name is not
defined or the file is not found by the
search, then this modifier expands to the
empty string
The modifiers can be combined to get compound results:
%~dpI - expands %I to a drive letter and path only
%~nxI - expands %I to a file name and extension only
%~fsI - expands %I to a full path name with short names only
%~dp$PATH:I - searches the directories listed in the PATH
environment variable for %I and expands to the
drive letter and path of the first one found.
%~ftzaI - expands %I to a DIR like output line
In the above examples %I and PATH can be replaced by other valid
values. The %~ syntax is terminated by a valid FOR variable name.
Picking upper case variable names like %I makes it more readable and
avoids confusion with the modifiers, which are not case sensitive.

Answer 2

As was mentioned in the comments, you could use powershell for this task. Here's a basic idea.
For the example file content:
1,2,,3,3,5,,
5,6,,7,12.3,6,,
9,10,,11,11.4,7,,
13,14,,15,10.1,2,,
You could use something like:
Import-Csv -Path ".\sample.csv" -Header ("A","B","C","D","E") | Sort-Object { [Single]$_.E } -Descending | Select-Object -First 1 -ExpandProperty E
Which should return:
12.3
As you can see above, because you had not supplied the header record, I had to create some in order to identify my target field. However, if you already have known header fields, you could simplify the code a little.
For the example file content:
This,Is,My,Actual,Header,Record,,
1,2,,3,3,5,,
5,6,,7,12.3,6,,
9,10,,11,11.4,7,,
13,14,,15,10.1,2,,
You would just name your field according to its header value name, something like:
Import-Csv -Path ".\sample.csv" | Sort-Object { [Single]$_.Header } -Descending | Select-Object -First 1 -ExpandProperty Header
Which should, once again, return:
12.3