Awk script - loop through row values of two columns in a csv file [duplicate]

Question

I am working with a huge CSV file (filtest.csv) that contains two columns. From column 1, I wanted to read current row and compare it with the value of the previous row. If it is greater OR equal, continue comparing and if the value of the current cell is smaller than the previous row - then i wanted to jump to the second column and take the value in the current row (of the second column). Next I wanted to divided the larger value we got in column 1 by the value in the same cell of column two with that of the smaller value in column 1. Let me clarify with this example. For example in the following table: the smaller value we will be depending on my requirement from Column 1 is 327 (because 327 is smaller than the previous value 340) - and then we take 500 (which is the corresponding cell value on column 2). Finally we divide 340 by 500 and get the value 0.68. My bash script should exit right after we print the value to the console.

In the following script, I tried it to do the division operation on the same row of the two columns and it works fine

awk -F, '$1<p && $2!=0{ 
val=$1/$2     
if(val>=0.85 && val<=0.9)
    {
        print "value is:" $1/p
        print "A"
    }
else if(val==0.8)
    {
        print "B"
    }
else if(val>=0.5 && val <=0.7)
    {
        print "C" 

    }
else if(val==0.5)
    {
        print "E"
    }
else
    {
        print "D" 
    }
exit
}
{ 
    p=$1 
}' filetest.csv

But how can we loop through the values in two columns and perform control statements on two different rows of the two columns as i mentioned earlier?

replace val=$1/$2 with val=p/$2

RomanPerekhrest
– RomanPerekhrest

2017-05-05 14:36:16 +00:00
Commented May 5, 2017 at 14:36 — RomanPerekhrest
– RomanPerekhrest, Commented May 5, 2017 at 14:36

Nahuel Fouilleul · Accepted Answer · 2017-05-05 11:42:08Z

1

From first description

 awk -F, '$1<prev{print prev/$2;exit}{prev=$1}' <input.txt

At the end of each line, 1st column is stored in prev Then when value of 1st column is least than prev, it prints the ratio and exits

answered May 5, 2017 at 11:42

Nahuel Fouilleul

19.5k2 gold badges36 silver badges37 bronze badges

Sign up to request clarification or add additional context in comments.

7 Comments

Mahsolid Over a year ago

I have already done that

Nahuel Fouilleul Over a year ago

can you explain "loop through the values in two columns and perform control statements" with examples input and expected output

Mahsolid Over a year ago

The example is in the first paragraph, dear.

James Brown Over a year ago

Exactly where in the first paragraph? I don't understand that question either.

Ed Morton Over a year ago

So the desired output of your script given your posted sample input is 0.68? Whats all that stuff about

the criteria for my if-else statement will be something like (if the value is >=0.8 and <=0.9, print A, else if the value) is >=0.7 and <=0.8, print B, if the value is >=0.5 and <=0.7 print C otherwise print D).

related to? Your question is not clear at all. Please edit your question to clearly state the expected output given that input and explain what all that other logic you describe is about.

|

Collectives™ on Stack Overflow

Awk script - loop through row values of two columns in a csv file [duplicate]

1 Answer 1

7 Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

7 Comments

Linked

Related