#include <stdio.h> #include <math.h> #define pi 3.14159265358979323846 double meridianarclength(double b) { double a = 6378140.0; double e2 = 0.00669438002290; double m = a * (1 - e2) * (1 - e2 * sin(b) * sin(b)) * pow(1 - e2 * sin(b) * sin(b), 1.5); double n = a / sqrt(1 - e2 * sin(b) * sin(b)); return m + n * sin(b) * cos(b) * pow(tan(b),2) /2 + n * sin(b) * pow(cos(b), 3) * (5 - pow(tan(b), 2) + 9 * e2 * pow(cos(b), 2)) * pow(tan(b), 4) / 24; } double calculatebaselatitude(double x,