October 15, 2012 Specifying precision in %(...%) print format | ||||
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I have an array of reals that I want to format with writefln, but the precision field needs to be passed in a variable. For a single real, it would be writefln("%.*f", precision, x); but when I try this:
int precision = ...;
real[] array = ...;
writefln("%(%.*f, %)", precision, array);
I get a runtime exception with the message "integral". I assume that's because %(%) is expecting an array, but sees an int, so it fails. But swapping the order of parameters doesn't help either:
writefln("%(%.*f, %)", array, precision);
produces "floating point format failure".
What's the right way to do this?
T
--
Trying to define yourself is like trying to bite your own teeth. -- Alan Watts
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October 15, 2012 Re: Specifying precision in %(...%) print format | ||||
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Posted in reply to H. S. Teoh | On 10/14/2012 10:43 PM, H. S. Teoh wrote:
> I have an array of reals that I want to format with writefln, but the
> precision field needs to be passed in a variable. For a single real, it
> would be writefln("%.*f", precision, x); but when I try this:
>
> int precision = ...;
> real[] array = ...;
> writefln("%(%.*f, %)", precision, array);
>
> I get a runtime exception with the message "integral". I assume that's
> because %(%) is expecting an array, but sees an int, so it fails. But
> swapping the order of parameters doesn't help either:
>
> writefln("%(%.*f, %)", array, precision);
>
> produces "floating point format failure".
>
> What's the right way to do this?
>
>
> T
>
Here is a way with format:
import std.stdio;
import std.string;
void main()
{
int precision = 2;
real[] array = [ 1.234 ];
writefln(format("%%(%%.%sf, %%)", precision), array);
}
Ali
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