Convert Longitude 0-360 to -180 to 180 or 180W-180E in fortran and matlab, transform lat lon coordinates

Variables in explanation
long1 is the longitude varying from -180 to 180 or 180W-180E
long3 is the longitude variable from 0 to 360 (all positive)

To convert longitude from (0-360) to (-180 to 180)

Matlab and fortran
long1=mod((long3+180),360)-180

Matlab
long1=rem((long3+180),360)-180

Fortran
long1=modulo((long3+180),360)-180


To convert longitude from (-180 to 180) to (0-360)

Matlab
lon3=mod(lon1,360)

Fortran
lon3=modulo(lon1,360)


The “mod” function is Fortran is equivalent to “rem” function in Matlab.

The “modulo” function in Fortran is equivalent to “mod” function in Matlab.

int2str and str2num in fortran, How convert string to integer number of vice versa.

To convert a number/integer to a string, you need to write the variable into the string character.

Integer I
Character* str
I = 9999
Write( str, '(i10)' ) I
End


To convert a string to number or integer, you need to read the strign and assign it to the integer

Integer I
Character* str
I = 9999
read( str, '(i10)' ) I
End