text: import {atan, cos, tan} from "./math";
  import parallel1 from "./parallel1";
  
  export function cylindricalStereographicRaw(phi0) {
    var cosPhi0 = cos(phi0);
  
    function forward(lambda, phi) {
      return [lambda * cosPhi0, (1 + cosPhi0) * tan(phi / 2)];
    }
  
    forward.invert = function(x, y) {
      return [x / cosPhi0, atan(y / (1 + cosPhi0)) * 2];
    };
  
    return forward;
  }
  
  export default function() {
    return parallel1(cylindricalStereographicRaw)
        .scale(124.75);
  }
  