Method doFit

ij/src/main/java/ij/plugin/frame/Fitter.java:84–123

Fit data in the textArea, show result in log and create plot. @param fitType as defined in CurveFitter constants @return false on error.

(int fitType)

     *  @return false on error.
     */
	public boolean doFit(int fitType) {
		if (!getData()) {
            IJ.beep();
			return false;
		}
		cf = new CurveFitter(x, y);
		cf.setStatusAndEsc("Optimization: Iteration ", true);
		try {
            if (fitType==USER_DEFINED) {
                String eqn = getEquation();
                if (eqn==null) return false;
                int params = cf.doCustomFit(eqn, null, settings.getState());
                if (params==0) {
                    IJ.beep();
                    IJ.log("Bad formula; should be:\n   y = function(x, a, ...)");
                    return false;
                }
            } else
                cf.doFit(fitType, settings.getState());
            if (cf.getStatus() == Minimizer.INITIALIZATION_FAILURE) {
                IJ.beep();
                IJ.showStatus(cf.getStatusString());
                IJ.log("Curve Fitting Error:\n"+cf.getStatusString());
                return false;
            }
            if (Double.isNaN(cf.getSumResidualsSqr())) {
                IJ.beep();
                IJ.showStatus("Error: fit yields Not-a-Number");
                return false;
            }
            
		} catch (Exception e) {
            IJ.handleException(e);
            return false;
		}
        IJ.log(cf.getResultString());
		plot(cf);
		this.fitType = fitType; 
		return true;
	}
	
	String getEquation() {
		GenericDialog gd = new GenericDialog("Formula");