Hi

how to format a float alike 50.3502 to show degrees minutes:

sprintf(bufflon,"Longitude: %2.4f\n", lon);

Same as:

http://transition.fcc.gov/mb/audio/bickel/DDDMMSS-decimal.html

basically multiply the .3502 with 60

Many thanks

Round the value to an integer to get the integer part of the angle. Then subtract that from the real angle to get the decimal part, and multiply by 60 to convert to minutes.

float degrees = floor(lon); float minutes = (lon - degrees) * 60; sprintf(bufflon,"Longitude: %.0f degrees, %f minutes\n", degrees, minutes);

This should work, in c++, for degree, minutes and second (just ignore the last part if you don't need seconds)

float  angle = 50.3502; // or whatever value
int degree = (int)angle;
int minutes = (int) ((angle - (float)degree) * 60.f);
int seconds = (int)(angle - (float)degree - (float)minutes/60.f) * 60.f * 60.f); // ignore this line if you don't need seconds

You don't strictly need all the explicit conversions, but I like to make sure that values are treated as they should be.

Note this will give you only whole values of degree/minutes/seconds. Your specific value (50.3502) actually ends up having a fraction of a second.

Thanks Milcho and Brother Bob. The seconds from Milcho don't work and I cannot figure the error. Also I would like to write E or W:

int seconds=?

sprintf (bufflon, "Longitude: "(lon<0?"W ":"E ")""%d*%d.%d", degree, minutes,seconds);

Many thanks again

Thanks Rip-off, now for seconds it's probably a bracket problem?

int degree = (int)lon;
int minutes = (int) ((lon - (float)degree) * 60.f);
int seconds = (int)(lon - (float)degree - (float)minutes * 60.f * 60.f); // tried all kind of variants but all were different to the output as in the above site.

Thanks again for help with seconds.

My bad, my original post was missing a parenthasis in the seconds column. The way you corrected that however won't give you the right results. Try this: (this time I tested this by compiling with gcc):

int degree = (int)lon;
int minutes = (int) ( (lon - (float)degree) * 60.f);
int seconds = (int) ( (lon - (float)degree - (float)minutes / 60.f) * 60.f * 60.f );

I tested the above to compare with the site - and it works fine, but due to the fact that it's using floats and not doubles there's some accuracy lost that sometimes gave me a result that was a second off. In order to fix this, you would have to make sure you store your 'lon' variable as a double, not a float, and use this version:

int degree = (int)lon;
int minutes = (int) ( (lon - (double)degree) * 60.0);
int seconds = (int) ( (lon - (double)degree - (double)minutes / 60.0) * 60.0 * 60.0 );

- this will also work with your lon variable being stored as a 'float' - but it won't give any improvements unless you store the original variable as a double (and no, converting from float to double right before calculation won't help either).