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CALC: Undocumented cell format found, for astro-nav calcs in degrees:minutes:seconds and decimal seconds. I request full info soon if available.

asked 2018-11-15 15:41:08 +0200

GilesW gravatar image

updated 2018-11-15 15:48:07 +0200

As a beginner in astronomy, I understand that: In astro-navigation etc., angles are usually written in degrees:minutes:seconds of arc, in the form [+-dd:dm:ds.s] for latitudes -90 to +90 degrees or [+-ddd:dm:ds.s] for longitudes 0 to 180 deg east or west, or their corresponding 'Hour Angles' [+-hh:mm:ss.s] usually between +-12 hours, there being 15 degrees longitude per hour. I find that Calc allows these formats, not documented in the "Format: Cells: Number" menus or Help. Calc sometimes automatically 'corrects negative angles wrong' as displayed, but fortunately without changing the content of the cell as entered. I found that inserting the text prefix ' for those angles, e.g. ['-ddd:dm:ds.s] surprisingly solves the problem, preventing 'automatic correction' of entered data while still allowing its use in calculations giving correct results. For use in trig functions [SIN() etc.] it is necessary to convert such angles to decimal format, then to radians by multiplying the decimal angle by PI()/180, and the reverse for inverse trig functions ASIN() etc. Can 'Cell Format' and Help info be updated?

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you request soon what?

wrt your "inquiry": please be more specific which format you use, which values give you what, and why it's incorrect. The description you gave uses some strange format specifiers possibly valid for your area, but not for calc.

Mike Kaganski gravatar imageMike Kaganski ( 2018-11-15 16:06:01 +0200 )edit

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answered 2018-11-15 16:54:10 +0200

erAck gravatar image

An input of '-ddd:dm:ds.s appears to work because the leading apostrophe forces the input to text. It does not enter a numeric value to the cell. An input of ddd:dm:ds.s yields a time (wall clock or duration) input, not anything related to degrees. For example, input 123:34:56 and clear the automatically applied time format (Ctrl+M) on the cell and you'll see the underlying number 5.14925925925926 (the time value in days, 123 hours plus 34 minutes plus 56 seconds).

Date+time are calculated as serial date numbers, days since null date (usually 1899-12-30), and time is fraction of days, so 0.5 = 12h. You can format such number (e.g. -0.5 to 0.5) as [HH]:MM:SS.00 to display the corresponding hours:minutes:seconds.fractions value.

There also is no "degrees" number format, so there's nothing to add to the cell format help.

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Asked: 2018-11-15 15:41:08 +0200

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Last updated: Nov 15 '18