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Join Date: Aug 2004
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Newbie Poster
Hi,
I'm trying to compare two text files (outputs from a database and corresponding spatial table in a GIS) to check for errors. Basically, i'm assuming that the output from the database is correct and any missing/repeat numbers in the spatial table will be errors and should be reported. I've written the part of the program that searches for a specific number in the spatial output and returns the errors, but i can't work out how to change the number it's searching for.
Here's what i've done so far:
As you can see, so far it only searches for how many times the specific number 5 appears in the SP.text file.
What i'd like it to do is read the DB.txt file, find the first number to search for, then find out how many times it appears in SP.txt, then move on to the next number in DB and repeat until the end, generating a txt file output of all the errors. The SP.txt file has every number containted within inverted commas, and the DB.txt file has each number at the beginning of a new line follow by a lot of " delineated text/
Any help would be greatly appreciated, as would any 'you're making this a lot more complicated that it needs to be, here's how you can solve your problem in fifteen seconds'
P.S apologies for length
I'm trying to compare two text files (outputs from a database and corresponding spatial table in a GIS) to check for errors. Basically, i'm assuming that the output from the database is correct and any missing/repeat numbers in the spatial table will be errors and should be reported. I've written the part of the program that searches for a specific number in the spatial output and returns the errors, but i can't work out how to change the number it's searching for.
Here's what i've done so far:
#include <string>
#include <fstream>
#include <iostream>
#include <stdlib.h>
using namespace std;
fstream DBinput("DB.txt", ios::in);
fstream SPinput("SP.txt", ios::in);
fstream output("Errors.txt", ios::out);
int i = 0;
string correct;
string word;
void count(void);
void SPcompare(void);
void main(void)
{
while(DBinput >> correct)
{
//////// Presumably this is where the 'find number to search for' part should come in ////////
SPcompare();
}
}
void SPcompare(void)
{
while(SPinput >> word)
{
count();
}
if(i == 0)
output << "Error - '" << word << "' has no matches in spatial database" << '\n';
else if(i > 1)
output << "Error - '" << word << "' has " << i << " matches in spatial database" << '\n';
}
void count(void)
{
if(word == "5")
i++;
}As you can see, so far it only searches for how many times the specific number 5 appears in the SP.text file.
What i'd like it to do is read the DB.txt file, find the first number to search for, then find out how many times it appears in SP.txt, then move on to the next number in DB and repeat until the end, generating a txt file output of all the errors. The SP.txt file has every number containted within inverted commas, and the DB.txt file has each number at the beginning of a new line follow by a lot of " delineated text/
Any help would be greatly appreciated, as would any 'you're making this a lot more complicated that it needs to be, here's how you can solve your problem in fifteen seconds'
P.S apologies for length
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Join Date: Aug 2004
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Newbie Poster
On the subject of an easier solution, is there some way that i can use string compare... ie something like:
Or will this try and compare the entire document or line or something? How can i narrow it down to only comparing individual values within the file?
if(strcmp(correct, word) == 0) cout << "Number has no errors" << '\n';
Or will this try and compare the entire document or line or something? How can i narrow it down to only comparing individual values within the file?
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Join Date: Jun 2004
Location: Marin, CA, USA
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Unprevaricator
Can we see a couple of lines of example for each file? Sounds like you want to
seems like the easiest part of this is the compare! :-)
open db
while lines left in db
read next line of db
trim off everything after the leading number
open sp
while lines left in sp
read next line of sp
(is there one number per line? several?)
parse next/only number from that line
COMPARE NUMBER FROM SP WITH NUMBER FROM DB
(go on to next number in the same line?)
end
close sp
end
close db
print totals •
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Join Date: Aug 2004
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Newbie Poster
That's pretty much exactly what i want to do, except there's not guarantee that the two numbers that need comparing will be on the same line, so using the DB file as a master it should:
SP file is in the form:
DB file is in the form:
And i'm trying to extract the 299, 300, etc numbers to search for in the other one (real files contain many thousands of entries to be compared). Also the SP numbers will not neccessarily be in order (almost certainly won't be, actually). That's pretty much the nature of the beast...
Hope that made sense...
while lines left in db
read next line of db
trim off everything after the leading number
open sp
while lines left in sp
search SP for leading number in DB
if number appears only once then proceed to find next number in DB, otherwise output an error to a txt file
endSP file is in the form:
"6853" "6854" "6855" "6856" "6857" "6858" "6859" "6860" "6861" "6862" "6863" "6864" "6865" "6866" "6867" "6868" "6869" "6870" "6871"
DB file is in the form:
299 "Planning" "Land Use" "Urban Land Uses" "Industry & Commerce" "Retailing" "n/a" "1" "n/a" "n/a" "n/a" 0 0 "n/a" "n/a" "" "" "n/a" "28/04/2003" "" 0 0 0 0 0 0 "Land use baseline report" 300 "Planning" "Land Use" "Urban Land Uses" "Industry & Commerce" "Industry" "n/a" "2" "n/a" "n/a" "n/a" 0 0 "n/a" "n/a" "" "Associated carpark" "n/a" "28/04/2003" "" 0 0 0 0 0 0 "Land use baseline report" etc
Hope that made sense...
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Join Date: Jun 2004
Location: Marin, CA, USA
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Unprevaricator
since the numbers in the db file are at the BEGINNING of the line, you could just use the library function 'atoi()' to get the number:
string lineFromDBFile;
. . .
int numberToLookFor = atoi( lineFromDBFile.c_str() );
For the SP file, if you KNOW that the numbers are always at the start of the line, AND they are always within quotes like shown, you could also use atoi():
int numberInSPFile = atoi( lineFromSPFile.c_str() + 1 ); // +1 skips the leading quote
Then you can say
[code]
bool numberFoundAlready = false;
...
<fetch next line from SP file>
...
if (numberInSPFile == numberToLookFor)
{
if (numberFoundAlready)
{
// do what you want when a duplicate is found
}
else
{
numberFoundAlready = true;
}
}
<go back for more SP lines>
string lineFromDBFile;
. . .
int numberToLookFor = atoi( lineFromDBFile.c_str() );
For the SP file, if you KNOW that the numbers are always at the start of the line, AND they are always within quotes like shown, you could also use atoi():
int numberInSPFile = atoi( lineFromSPFile.c_str() + 1 ); // +1 skips the leading quote
Then you can say
[code]
bool numberFoundAlready = false;
...
<fetch next line from SP file>
...
if (numberInSPFile == numberToLookFor)
{
if (numberFoundAlready)
{
// do what you want when a duplicate is found
}
else
{
numberFoundAlready = true;
}
}
<go back for more SP lines>
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Join Date: Jun 2004
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Unprevaricator
RATS! Forgot the closing code bracket so it looks awful. Sorry.
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Join Date: Aug 2004
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Newbie Poster
Cheers for that, i'll give it a whirl this evening when i'm near a c compiler (or i sort it out at work...).
In the meantime, i've made some changes to the database so it outputs to this program a lot more neatly, so now both text files contain numbers in the form:
with no uselesse data or " marks in it.
With that in mind, does anyone have any ideas why this doesn't work;
When it runs it makes an output file something like:
So it's only counting the first number from DB.txt, ie not updating the 'correct' string in the comparison if statement, and i don't understand why not, seeing as it's updating it in the cout statement.
Any ideas?
In the meantime, i've made some changes to the database so it outputs to this program a lot more neatly, so now both text files contain numbers in the form:
1 2 3 4 5 6 7 etc
with no uselesse data or " marks in it.
With that in mind, does anyone have any ideas why this doesn't work;
#include <string>
#include <fstream>
#include <iostream>
#include <stdlib.h>
using namespace std;
fstream DBinput("DB.txt", ios::in);
fstream SPinput("SP.txt", ios::in);
fstream output("Errors.txt", ios::out);
int i = 0;
string correct;
string word;
void main(void)
{
while(DBinput >> correct)
{
while(SPinput >> word)
{
if(correct == word)
i++;
}
output << "There are "<< i << " matches for " << correct << "." << '\n';
i = 0;
}
}When it runs it makes an output file something like:
There are 1 matches for 1. There are 0 matches for 2. There are 0 matches for 3. There are 0 matches for 4. There are 0 matches for 5. There are 0 matches for 6. There are 0 matches for 7. etc
So it's only counting the first number from DB.txt, ie not updating the 'correct' string in the comparison if statement, and i don't understand why not, seeing as it's updating it in the cout statement.
Any ideas?
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Join Date: Apr 2004
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Originally Posted by Frogstar
So it's only counting the first number from DB.txt, ie not updating the 'correct' string in the comparison if statement, and i don't understand why not, seeing as it's updating it in the cout statement.
Any ideas?
I might try something like this.
#include <string>
#include <fstream>
#include <iostream>
using namespace std;
int main(void)
{
ifstream DBinput("DB.txt");
ofstream output("Errors.txt");
string correct;
while ( DBinput >> correct )
{
ifstream SPinput("SP.txt");
int i = 0;
string word;
while ( SPinput >> word )
{
if ( correct == word )
i++;
}
cout << correct << ": " << i << endl; // for debugging
output << "There are "<< i << " matches for " << correct << "." << '\n';
}
return 0;
} |
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