Re: [R] Format wanted...
On 12-03-24 10:47 PM, J Toll wrote: On Sat, Mar 24, 2012 at 7:30 PM, Duncan Murdoch murdoch.dun...@gmail.com wrote: Do we have a format that always includes a decimal point and a given number of significant digits, but otherwise drops unnecessary characters? For example, if I wanted 5 digits, I'd want the following: Round to 5 digits: 1.234567 - 1.2346 Drop unnecessary zeros: 1.23 - 1.23 Force inclusion of a decimal point: 1 - 1. Duncan, Maybe sprintf() will work for you. As it's a wrapper for C sprintf, it should have its functionality. Maybe, but with which format string? Duncan Murdoch __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Format wanted...
On Mar 25, 2012, at 7:14 AM, Duncan Murdoch wrote:
On 12-03-24 10:47 PM, J Toll wrote:
On Sat, Mar 24, 2012 at 7:30 PM, Duncan Murdoch
murdoch.dun...@gmail.com wrote:
Do we have a format that always includes a decimal point and a given number
of significant digits, but otherwise drops unnecessary characters? For
example, if I wanted 5 digits, I'd want the following:
Round to 5 digits:
1.234567 - 1.2346
Drop unnecessary zeros:
1.23 - 1.23
Force inclusion of a decimal point:
1 - 1.
Duncan,
Maybe sprintf() will work for you. As it's a wrapper for C sprintf,
it should have its functionality.
Maybe, but with which format string?
Duncan Murdoch
I don't believe (though could be wrong), that you can do it all with one format
string, but can do it conditionally based upon the input. According to the C
printf documentation, the use of # forces a decimal point to be present, even
if there are no trailing digits. Thus:
sprintf(%#.f, 1)
[1] 1.
The other two values seem to be handled by signif() when applied to each value
individually:
signif(1.234567, 5)
[1] 1.2346
signif(1.23, 5)
[1] 1.23
But, not when a vector:
signif(c(1.234567, 1.23), 5)
[1] 1.2346 1.2300
So, wrapping that inside a function, using ifelse() to test for an integer
value:
signif.d - function(x, digits)
{
ifelse(x == round(x),
sprintf(%.#f, x),
signif(x, digits))
}
x - c(1.234567, 1.23, 1)
signif.d(x, 5)
[1] 1.2346 1.23 1.
signif.d(x, 6)
[1] 1.23457 1.231.
signif.d(x, 7)
[1] 1.234567 1.23 1.
Not extensively tested of course, but hopefully that might work for your needs
Duncan.
Regards,
Marc Schwartz
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Re: [R] Format wanted...
On 12-03-25 10:45 AM, Marc Schwartz wrote:
On Mar 25, 2012, at 7:14 AM, Duncan Murdoch wrote:
On 12-03-24 10:47 PM, J Toll wrote:
On Sat, Mar 24, 2012 at 7:30 PM, Duncan Murdoch
murdoch.dun...@gmail.com wrote:
Do we have a format that always includes a decimal point and a given number
of significant digits, but otherwise drops unnecessary characters? For
example, if I wanted 5 digits, I'd want the following:
Round to 5 digits:
1.234567 - 1.2346
Drop unnecessary zeros:
1.23 - 1.23
Force inclusion of a decimal point:
1 - 1.
Duncan,
Maybe sprintf() will work for you. As it's a wrapper for C sprintf,
it should have its functionality.
Maybe, but with which format string?
Duncan Murdoch
I don't believe (though could be wrong), that you can do it all with one format string,
but can do it conditionally based upon the input. According to the C printf
documentation, the use of # forces a decimal point to be present, even if
there are no trailing digits. Thus:
sprintf(%#.f, 1)
[1] 1.
The other two values seem to be handled by signif() when applied to each value
individually:
signif(1.234567, 5)
[1] 1.2346
signif(1.23, 5)
[1] 1.23
But, not when a vector:
signif(c(1.234567, 1.23), 5)
[1] 1.2346 1.2300
So, wrapping that inside a function, using ifelse() to test for an integer
value:
signif.d- function(x, digits)
{
ifelse(x == round(x),
sprintf(%.#f, x),
signif(x, digits))
}
x- c(1.234567, 1.23, 1)
signif.d(x, 5)
[1] 1.2346 1.23 1.
signif.d(x, 6)
[1] 1.23457 1.231.
signif.d(x, 7)
[1] 1.234567 1.23 1.
Not extensively tested of course, but hopefully that might work for your needs
Duncan.
Thanks. I had put together a different conditional (just do the
conversion, then add a decimal point at the end if none is seen), but I
was surprised that there was no standard format for this.
In case anyone is interested, I want to output code in a language (GLSL)
that sees 1 and 1. as different types. I want a floating point value,
so I need the decimal point.
Duncan Murdoch
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Re: [R] Format wanted...
Duncan, On 25 March 2012 15:28, Duncan Murdoch murdoch.dun...@gmail.com wrote: In case anyone is interested, I want to output code in a language (GLSL) that sees 1 and 1. as different types. I want a floating point value, so I need the decimal point. GLSL, assuming it's the one that I'm looking at[1], supports implicit conversion from integer to float by appending .0 to the end. -- Sent from my mobile device Envoyait de mon portable 1. http://www.opengl.org/wiki/GLSL_Types#Implicit_conversion __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
[R] Format wanted...
Do we have a format that always includes a decimal point and a given number of significant digits, but otherwise drops unnecessary characters? For example, if I wanted 5 digits, I'd want the following: Round to 5 digits: 1.234567 - 1.2346 Drop unnecessary zeros: 1.23 - 1.23 Force inclusion of a decimal point: 1 - 1. Duncan Murdoch __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Format wanted...
On Sat, Mar 24, 2012 at 7:30 PM, Duncan Murdoch murdoch.dun...@gmail.com wrote: Do we have a format that always includes a decimal point and a given number of significant digits, but otherwise drops unnecessary characters? For example, if I wanted 5 digits, I'd want the following: Round to 5 digits: 1.234567 - 1.2346 Drop unnecessary zeros: 1.23 - 1.23 Force inclusion of a decimal point: 1 - 1. Duncan, Maybe sprintf() will work for you. As it's a wrapper for C sprintf, it should have its functionality. James __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
