Hi,
I try to convert double to string as below:
std::string cnvrtToString(d ouble lValue)
{
std::ostringstr eam lStream;
lStream << lValue;
return lStream.str();
}
however I found that I have lost the accuracy(having lesser decimal
value) of my result after I print it to an outfile by doing
fprintf(File, "%s", stream.ctr());
I am not able to print directly:
fprintf(File, "%f", lValue); as I need to format my outfile
appropriately.
I wonder if the lost of accuracy happen when I convert double to
string? If yes, is there anyway I can avoid that?
Please correct me if I am wrong.
Thnak you.
jeff 3 2315 je***********@y ahoo.com wrote: I try to convert double to string as below:
std::string cnvrtToString(d ouble lValue) { std::ostringstr eam lStream; lStream << lValue; return lStream.str(); }
however I found that I have lost the accuracy(having lesser decimal value) of my result after I print it to an outfile by doing fprintf(File, "%s", stream.ctr());
I am not able to print directly: fprintf(File, "%f", lValue); as I need to format my outfile appropriately.
I wonder if the lost of accuracy happen when I convert double to string? If yes, is there anyway I can avoid that?
Using your terms, yes, it does. The default "accuracy" is 6 digits
after the decimal point. If your value is around 1, you lose more
than half the digits. You need 'setprecision(1 6)' (for most double
representations out there).
V
could you please explain in more detail how and where to include the
setprecision?
thanks
jeff
<je***********@ yahoo.com> wrote in message
news:11******** **************@ g14g2000cwa.goo glegroups.com.. . could you please explain in more detail how and where to include the setprecision?
Insert it into the stream.
#include <iomanip>
#include <iostream>
int main()
{
double d(1.23456789);
std::cout << std::setprecisi on(16);
std::cout << d << '\n';
return 0;
}
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