How to do arithmetic with floating point numbers such as 1.503923 in a shell script? The floating point numbers are pulled from a file as a string. The format of the file is as follows:
1.5493482,3.49384,33.284732,23.043852,2.2384...
3.384,3.282342,23.043852,2.23284,8.39283...
.
.
.
Here is some simplified sample code I need to get working. Everything works fine up to the arithmetic. I pull a line from the file, then pull multiple values from that line. I think this would cut down on search processing time as these files are huge.
# set vars, loops etc.
while [ $line_no -gt 0 ]
do
line_string=`sed -n $line_no'p' $file_path` # Pull Line (str) from a file
string1=${line_string:9:6} # Pull value from the Line
string2=${line_string:16:6}
string3=...
.
.
.
calc1= `expr $string2 - $string7` |bc -l # I tried these and various
calc2= ` "$string3" * "$string2" ` |bc -l # other combinations
calc3= `expr $string2 - $string1`
calc4= "$string2 + $string8" |bc
.
.
.
generic_function_call # Use the variables in functions
line_no=`expr $line_no - 1` # Counter--
done
Output I keep getting:
expr: non-numeric argument
command not found
I believe you should use : bc
For example:
echo "scale = 10; 123.456789/345.345345" | bc
(It's the unix way: each tool specializes to do well what they are supposed to do, and they all work together to do great things. don't emulate a great tool with another, make them work together.)
Output:
.3574879198
Or with a scale of 1 instead of 10:
echo "scale = 1; 123.456789/345.345345" | bc
Output:
.3
Note that this does not perform rounding.
I highly recommand switching to awk if you need to do more complex operations, or perl for the most complex ones.
ex: your operations done with awk:
# create the test file:
printf '1.5493482,3.49384,33.284732,23.043852,2.2384,12.1,13.4,...\n' > somefile
printf '3.384,3.282342,23.043852,2.23284,8.39283,14.1,15.2,...\n' >> somefile
# do OP's calculations (and DEBUG print them out!)
awk -F',' '
# put no single quote in here... even in comments! you can instead print a: \047
# the -F tell awk to use "," as a separator. Thus awk will automatically split lines for us using it.
# $1=before first "," $2=between 1st and 2nd "," ... etc.
function some_awk_function_here_if_you_want() { # optionnal function definition
# some actions here. you can even have arguments to the function, etc.
print "DEBUG: no action defined in some_awk_function_here_if_you_want yet ..."
}
BEGIN { rem="Optionnal START section. here you can put initialisations, that happens before the FIRST file-s FIRST line is read"
}
(NF>=8) { rem="for each line with at least 8 values separated by commas (and only for lines meeting that condition)"
calc1=($2 - $7)
calc2=($3 * $2)
calc3=($2 - $1)
calc4=($2 + $8)
# uncomment to call this function :(ex1): # some_awk_function_here_if_you_want
# uncomment to call this script:(ex2): # cmd="/path/to/some/script.sh \"" calc1 "\" \"" calc2 "\" ..." ; rem="continued next line"
# uncomment to call this script:(ex2): # system(cmd); close(cmd)
line_no=(FNR-1) # ? why -1? . FNR=line number in the CURRENT file. NR=line number since the beginning (NR>FNR after the first file ...)
print "DEBUG: calc1=" calc1 " , calc2=" calc2 " , calc3=" calc3 " , calc4=" calc4 " , line_no=" line_no
print "DEBUG fancier_exemples: see man printf for lots of info on formatting (%...f for floats, %...d for integer, %...s for strings, etc)"
printf("DEBUG: calc1=%d , calc2=%10.2f , calc3=%s , calc4=%d , line_no=%d\n",calc1, calc2, calc3, calc4, line_no)
}
END { rem="Optionnal END section. here you can put things that need to happen AFTER the LAST file-s LAST line is read"
}
' somefile # end of the awk script, and the list of file(s) to be read by it.
What about this?
calc=$(echo "$String2 + $String8"|bc)
This will make bc to add the values of $String2 and $String8 and saves the result in the variable calc.
If you don't have the "bc" you can just use 'awk' :
calc=$(echo 2.3 4.6 | awk '{ printf "%f", $1 + $2 }')
scale in bc is the precission so with a scale of 4 if you type bc <<< 'scale=4;22.0/7' you get 3.1428 as an answer. If you use a scale of 8 you get 3.14285714 which is 8 numbers after the floating point.
So the scale is a precission factor
Related
How to do arithmetic with floating point numbers such as 1.503923 in a shell script? The floating point numbers are pulled from a file as a string. The format of the file is as follows:
1.5493482,3.49384,33.284732,23.043852,2.2384...
3.384,3.282342,23.043852,2.23284,8.39283...
.
.
.
Here is some simplified sample code I need to get working. Everything works fine up to the arithmetic. I pull a line from the file, then pull multiple values from that line. I think this would cut down on search processing time as these files are huge.
# set vars, loops etc.
while [ $line_no -gt 0 ]
do
line_string=`sed -n $line_no'p' $file_path` # Pull Line (str) from a file
string1=${line_string:9:6} # Pull value from the Line
string2=${line_string:16:6}
string3=...
.
.
.
calc1= `expr $string2 - $string7` |bc -l # I tried these and various
calc2= ` "$string3" * "$string2" ` |bc -l # other combinations
calc3= `expr $string2 - $string1`
calc4= "$string2 + $string8" |bc
.
.
.
generic_function_call # Use the variables in functions
line_no=`expr $line_no - 1` # Counter--
done
Output I keep getting:
expr: non-numeric argument
command not found
I believe you should use : bc
For example:
echo "scale = 10; 123.456789/345.345345" | bc
(It's the unix way: each tool specializes to do well what they are supposed to do, and they all work together to do great things. don't emulate a great tool with another, make them work together.)
Output:
.3574879198
Or with a scale of 1 instead of 10:
echo "scale = 1; 123.456789/345.345345" | bc
Output:
.3
Note that this does not perform rounding.
I highly recommand switching to awk if you need to do more complex operations, or perl for the most complex ones.
ex: your operations done with awk:
# create the test file:
printf '1.5493482,3.49384,33.284732,23.043852,2.2384,12.1,13.4,...\n' > somefile
printf '3.384,3.282342,23.043852,2.23284,8.39283,14.1,15.2,...\n' >> somefile
# do OP's calculations (and DEBUG print them out!)
awk -F',' '
# put no single quote in here... even in comments! you can instead print a: \047
# the -F tell awk to use "," as a separator. Thus awk will automatically split lines for us using it.
# $1=before first "," $2=between 1st and 2nd "," ... etc.
function some_awk_function_here_if_you_want() { # optionnal function definition
# some actions here. you can even have arguments to the function, etc.
print "DEBUG: no action defined in some_awk_function_here_if_you_want yet ..."
}
BEGIN { rem="Optionnal START section. here you can put initialisations, that happens before the FIRST file-s FIRST line is read"
}
(NF>=8) { rem="for each line with at least 8 values separated by commas (and only for lines meeting that condition)"
calc1=($2 - $7)
calc2=($3 * $2)
calc3=($2 - $1)
calc4=($2 + $8)
# uncomment to call this function :(ex1): # some_awk_function_here_if_you_want
# uncomment to call this script:(ex2): # cmd="/path/to/some/script.sh \"" calc1 "\" \"" calc2 "\" ..." ; rem="continued next line"
# uncomment to call this script:(ex2): # system(cmd); close(cmd)
line_no=(FNR-1) # ? why -1? . FNR=line number in the CURRENT file. NR=line number since the beginning (NR>FNR after the first file ...)
print "DEBUG: calc1=" calc1 " , calc2=" calc2 " , calc3=" calc3 " , calc4=" calc4 " , line_no=" line_no
print "DEBUG fancier_exemples: see man printf for lots of info on formatting (%...f for floats, %...d for integer, %...s for strings, etc)"
printf("DEBUG: calc1=%d , calc2=%10.2f , calc3=%s , calc4=%d , line_no=%d\n",calc1, calc2, calc3, calc4, line_no)
}
END { rem="Optionnal END section. here you can put things that need to happen AFTER the LAST file-s LAST line is read"
}
' somefile # end of the awk script, and the list of file(s) to be read by it.
What about this?
calc=$(echo "$String2 + $String8"|bc)
This will make bc to add the values of $String2 and $String8 and saves the result in the variable calc.
If you don't have the "bc" you can just use 'awk' :
calc=$(echo 2.3 4.6 | awk '{ printf "%f", $1 + $2 }')
scale in bc is the precission so with a scale of 4 if you type bc <<< 'scale=4;22.0/7' you get 3.1428 as an answer. If you use a scale of 8 you get 3.14285714 which is 8 numbers after the floating point.
So the scale is a precission factor
I need a help with my bash script. I've problem with code:
for v in $(seq 1 $f)); do echo $(grep "Freq" freq.log) | awk '{print$3}')
because this comands printed $f times column number 3 instead should be printed $f values of "Freq" from column number 3.
It's look like
enter image description here
Should be like
enter image description here
I don't know how make that variable $f defined how much "Freq" will be printed from column number 3. In this file I've plenty expressions of "Freq" but I need just $f.
For sure I pasted all content of script:
#!/bin/bash
e=$(grep "atomic number" freq.log | tail -1 | awk '{print$2}')
echo "Liczba atomow znajdujacyh sie w podanej czasteczce wynosi: $e"
f=$(bc <<< "($e*3-6)/3")
echo "Liczba wartosci Freq, ktore wczyta skrypt to $f"
for v in $(seq 1 $f); do
echo "$(grep "Freq" freq.log | awk '{print$3}')"
done
Sample input data file; geometry optimization calculations in GAUSSIAN
A A A
Frequencies -- 182.1477 202.8948 227.7144
Red. masses -- 6.6528 8.2622 6.3837
Frc consts -- 0.1300 0.2004 0.1950
IR Inten -- 0.8602 0.4870 1.2090
NAtoms= 35 NActive= 35 NUniq= 35 SFac= 1.00D+00 NAtFMM= 60 NAOKFM=F Big=F
Here is your bash script converted to a single awk script:
awk script script.awk
/atomic number/{ # for each line matching regEx pattern "atomic number"
e = $2; # store current 2nd field in variable e
}
/Freq/{ # for each line matching regEx pattern "Freq"
freqArr[fr++]=$3; # add 3rd field to array freqArr, increment array counter fr
}
END { # on complete scanning input file
print "Liczba atomow znajdujacyh sie w podanej czasteczce wynosi: " e;
f = ( ((e * 3) - 6) / 3 ); # claculate vairable f
print "Liczba wartosci Freq, ktore wczyta skrypt to " f;
for (currFreq in freqArr) { # scan all element freqArr
if (currFreq == f) # if currFreq equals f
freqCount++; # increment freqCount coutner
}
print freqCount;
}
run command
awk -f script.awk freq.log
I need advice on how to achieve this output:
myoutputfile.txt
Tom Hagen 1892
State: Canada
Hank Moody 1555
State: Cuba
J.Lo 156
State: France
output of mycommand:
/usr/bin/mycommand
Tom Hagen
1892
Canada
Hank Moody
1555
Cuba
J.Lo
156
France
Im trying to achieve with this shell script:
IFS=$'\r\n' GLOBIGNORE='*' :; names=( $(/usr/bin/mycommand) )
for name in ${names[#]}
do
#echo $name
echo ${name[0]}
#echo ${name:0}
done
Thanks
Assuming you can always rely on the command to output groups of 3 lines, one option might be
/usr/bin/mycommand |
while read name;
read year;
read state; do
echo "$name $year"
echo "State: $state"
done
An array isn't really necessary here.
One improvement could be to exit the loop if you don't get all three required lines:
while read name && read year && read state; do
# Guaranteed that name, year, and state are all set
...
done
An easy one-liner (not tuned for performance):
/usr/bin/mycommand | xargs -d '\n' -L3 printf "%s %s\nState: %s\n"
It reads 3 lines at a time from the pipe and then passes them to a new instance of printf which is used to format the output.
If you have whitespace at the beginning (it looks like that in your example output), you may need to use something like this:
/usr/bin/mycommand | sed -e 's/^\s*//g' | xargs -d '\n' -L3 printf "%s %s\nState: %s\n"
#!/bin/bash
COUNTER=0
/usr/bin/mycommand | while read LINE
do
if [ $COUNTER = 0 ]; then
NAME="$LINE"
COUNTER=$(($COUNTER + 1))
elif [ $COUNTER = 1 ]; then
YEAR="$LINE"
COUNTER=$(($COUNTER + 1))
elif [ $COUNTER = 2 ]; then
STATE="$LINE"
COUNTER=0
echo "$NAME $YEAR"
echo "State: $STATE"
fi
done
chepner's pure bash solution is simple and elegant, but slow with large input files (loops in bash are slow).
Michael Jaros' solution is even simpler, if you have GNU xargs (verify with xargs --version), but also does not perform well with large input files (external utility printf is called once for every 3 input lines).
If performance matters, try the following awk solution:
/usr/bin/mycommand | awk '
{ ORS = (NR % 3 == 1 ? " " : "\n")
gsub("^[[:blank:]]+|[[:blank:]]*\r?$", "") }
{ print (NR % 3 == 0 ? "State: " : "") $0 }
' > myoutputfile.txt
NR % 3 returns the 0-based index of each input line within its respective group of consecutive 3 lines; returns 1 for the 1st line, 2 for the 2nd, and 0(!) for the 3rd.
{ ORS = (NR % 3 == 1 ? " " : "\n") determines ORS, the output-record separator, based on that index: a space for line 1, and a newline for lines 2 and 3; the space ensures that line 2 is appended to line 1 with a space when using print.
gsub("^[[:blank:]]+|[[:blank:]]*\r?$", "") strips leading and trailing whitespace from the line - including, if present, a trailing \r, which your input seems to have.
{ print (NR % 3 == 0 ? "State: " : "") $0 } prints the trimmed input line, prefixed by "State: " only for every 3rd input line, and implicitly followed by ORS (due to use of print).
I want to know if it is possible to calculate the difference between two float number contained in a file in two distinct lines in one bash command line.
File content example :
Start at 123456.789
...
...
...
End at 123654.987
I would like to do an echo of 123654.987-123456.789
Is that possible? What is this magic command line ?
Thank you!
awk '
/Start/ { start = $3 } # 3rd field in line matching "Start"
/End/ {
end = $3; # 3rd field in line matching "End"
print end - start # Print the difference.
}
' < file
If you really want to do this on one line:
awk '/Start/ { start = $3 } /End/ { end = $3; print end - start }' < file
you can do this with this command:
start=`grep 'Start' FILENAME| cut -d ' ' -f 3`; end=`grep 'End' FILENAME | cut -d ' ' -f 3`; echo "$end-$start" | bc
You need the 'bc' program for this (for floating point math). You can install it with apt-get install bc, or yum, or rpm, zypper... OS specific :)
Bash doesn't support floating point operations. But you can split your numbers to parts and perform integer operations. Example:
#!/bin/bash
echo $(( ${2%.*} - ${1%.*} )).$(( ${2#*.} - ${1#*.} ))
Result:
./test.sh 123456.789 123654.987
198.198
EDIT:
Correct solution would be using not command line hack, but tool designed or performing fp operations. For example, bc:
echo 123654.987-123456.789 | bc
output:
198.198
Here's a weird way:
printf -- "-%s+%s\n" $(grep -oP '(Start|End) at \K[\d.]+' file) | bc
How to do arithmetic with floating point numbers such as 1.503923 in a shell script? The floating point numbers are pulled from a file as a string. The format of the file is as follows:
1.5493482,3.49384,33.284732,23.043852,2.2384...
3.384,3.282342,23.043852,2.23284,8.39283...
.
.
.
Here is some simplified sample code I need to get working. Everything works fine up to the arithmetic. I pull a line from the file, then pull multiple values from that line. I think this would cut down on search processing time as these files are huge.
# set vars, loops etc.
while [ $line_no -gt 0 ]
do
line_string=`sed -n $line_no'p' $file_path` # Pull Line (str) from a file
string1=${line_string:9:6} # Pull value from the Line
string2=${line_string:16:6}
string3=...
.
.
.
calc1= `expr $string2 - $string7` |bc -l # I tried these and various
calc2= ` "$string3" * "$string2" ` |bc -l # other combinations
calc3= `expr $string2 - $string1`
calc4= "$string2 + $string8" |bc
.
.
.
generic_function_call # Use the variables in functions
line_no=`expr $line_no - 1` # Counter--
done
Output I keep getting:
expr: non-numeric argument
command not found
I believe you should use : bc
For example:
echo "scale = 10; 123.456789/345.345345" | bc
(It's the unix way: each tool specializes to do well what they are supposed to do, and they all work together to do great things. don't emulate a great tool with another, make them work together.)
Output:
.3574879198
Or with a scale of 1 instead of 10:
echo "scale = 1; 123.456789/345.345345" | bc
Output:
.3
Note that this does not perform rounding.
I highly recommand switching to awk if you need to do more complex operations, or perl for the most complex ones.
ex: your operations done with awk:
# create the test file:
printf '1.5493482,3.49384,33.284732,23.043852,2.2384,12.1,13.4,...\n' > somefile
printf '3.384,3.282342,23.043852,2.23284,8.39283,14.1,15.2,...\n' >> somefile
# do OP's calculations (and DEBUG print them out!)
awk -F',' '
# put no single quote in here... even in comments! you can instead print a: \047
# the -F tell awk to use "," as a separator. Thus awk will automatically split lines for us using it.
# $1=before first "," $2=between 1st and 2nd "," ... etc.
function some_awk_function_here_if_you_want() { # optionnal function definition
# some actions here. you can even have arguments to the function, etc.
print "DEBUG: no action defined in some_awk_function_here_if_you_want yet ..."
}
BEGIN { rem="Optionnal START section. here you can put initialisations, that happens before the FIRST file-s FIRST line is read"
}
(NF>=8) { rem="for each line with at least 8 values separated by commas (and only for lines meeting that condition)"
calc1=($2 - $7)
calc2=($3 * $2)
calc3=($2 - $1)
calc4=($2 + $8)
# uncomment to call this function :(ex1): # some_awk_function_here_if_you_want
# uncomment to call this script:(ex2): # cmd="/path/to/some/script.sh \"" calc1 "\" \"" calc2 "\" ..." ; rem="continued next line"
# uncomment to call this script:(ex2): # system(cmd); close(cmd)
line_no=(FNR-1) # ? why -1? . FNR=line number in the CURRENT file. NR=line number since the beginning (NR>FNR after the first file ...)
print "DEBUG: calc1=" calc1 " , calc2=" calc2 " , calc3=" calc3 " , calc4=" calc4 " , line_no=" line_no
print "DEBUG fancier_exemples: see man printf for lots of info on formatting (%...f for floats, %...d for integer, %...s for strings, etc)"
printf("DEBUG: calc1=%d , calc2=%10.2f , calc3=%s , calc4=%d , line_no=%d\n",calc1, calc2, calc3, calc4, line_no)
}
END { rem="Optionnal END section. here you can put things that need to happen AFTER the LAST file-s LAST line is read"
}
' somefile # end of the awk script, and the list of file(s) to be read by it.
What about this?
calc=$(echo "$String2 + $String8"|bc)
This will make bc to add the values of $String2 and $String8 and saves the result in the variable calc.
If you don't have the "bc" you can just use 'awk' :
calc=$(echo 2.3 4.6 | awk '{ printf "%f", $1 + $2 }')
scale in bc is the precission so with a scale of 4 if you type bc <<< 'scale=4;22.0/7' you get 3.1428 as an answer. If you use a scale of 8 you get 3.14285714 which is 8 numbers after the floating point.
So the scale is a precission factor