Pre-pend a zero to single digit number strings?

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I have a wave that contains one or two digit numbers (0 through 59). Mostly these are integers, but not all. I am using num2str to convert these to a string which I then concatenate with other similar strings.

I'd like to have the string read eg "07" instead of "7". Is there a way to format the string "numbers" so that 0 though 9 have a zero pre-pended but 10 through 59 don't?

So the following csv etries: 7,6,23.5 would be assemble as the string "07:06:23.5" (in other words, hours:mins:secs or degrees:mins:secs format)

At present the assembly I'm building reads "7:6:23.5"

Thanks

DN
hi!

printf "%02d", vNum


prints the number vNum with a leading zero. when using string variables you could use sprintf instead of num2str like


sprintf sString, "%02d", vNum


where now the string sString is the string representation of the single-digit number vNum with a leading zero and a two-digit number with no leading zero appended.

gregor

March 22, 2010 at 06:15 am - Permalink
I think Gregor meant "%.2d". The d format specifier prints integers, which it seems is what you want for the hours and minutes. To get seconds with two digits plus fraction with a leading zero for numbers less than 10 is quite difficult.

John Weeks
WaveMetrics, Inc.
support@wavemetrics.com

March 23, 2010 at 05:10 pm - Permalink
I think Gregor meant "%.2d". The d format specifier prints integers, which it seems is what you want for the hours and minutes. To get seconds with two digits plus fraction with a leading zero for numbers less than 10 is quite difficult.


Both "%02d" (use 2 digits with leading zeros) and "%.2d" (print two digits of precision) give the desired result:



Function Test(mode)
	Variable mode
	
	Variable i
	for(i=0; i<20; i+=1)
		String tmp
		if (mode == 0)
			sprintf tmp, "%02d\r", i
		else
			sprintf tmp, "%02d\r", i
		endif
		Print tmp
	endfor
End


To get seconds with two digits plus fraction with a leading zero for numbers less than 10 is quite difficult.


I would handle the fractional part separately. Here is my attempt:


//	Example: Print ConvertToHMSF(11*3600 + 12*60 + 13 + .14)
Function/S ConvertToHMSF(totalSeconds)
	Variable totalSeconds	// With possible fraction
	
	totalSeconds = mod(totalSeconds, 24*3600)	// Wrap around after 24 hours
	
	Variable remaining = totalSeconds
	
	Variable hours = trunc(remaining/3600)
	remaining -= 3600 * hours
	
	Variable minutes = trunc(remaining/60)
	remaining -= 60 * minutes
	
	Variable seconds = trunc(remaining)
	remaining -= seconds

	Variable frac = remaining
	
	String str
	sprintf str, "%02d:%02d:%02d.%.2d", hours, minutes, seconds, round(100*frac)
	return str	
End


March 23, 2010 at 06:38 pm - Permalink