public void weibullStandardProbabilityPlot(){
            this.lastMethod = 13;

            // Check for negative x values
            if(this.sortedData[0]<0){
                System.out.println("Method weibullStandardProbabilityPlot: negative x value found - weibullThreeParProbabilityPlot called");
                this.weibullThreeParProbabilityPlot();
            }

            // Check data for suffient points
            this.weibullStandardNumberOfParameters = 1;
            if(this.numberOfDataPoints<3)throw new IllegalArgumentException("There must be at least three data points - preferably considerably more");

            // Create instance of Regression
            Regression min = new Regression(this.sortedData, this.sortedData);

            // Calculate initial estimates
            double[] start = new double[1];
            start[0] = 4.0;
            double[] step = {Math.abs(0.3*start[0])};
            this.initialEstimates = start;
            double tolerance = 1e-10;

            // Add constraint; gamma>0
            min.addConstraint(0, -1, 0);

            // Create an instance of WeibullStandardProbPlotFunc
            WeibullStandardProbPlotFunc wppf = new WeibullStandardProbPlotFunc();
            wppf.setDataArray(this.numberOfDataPoints);

            // Obtain best probability plot varying gamma
            // by minimizing the sum of squares of the differences between the ordered data and the ordered statistic medians
            min.simplex(wppf, Conv.copy(start), step, tolerance);

            // Obtain best estimates or first minimisation
            double[] firstBests = min.getBestEstimates();

            // Get mu and sigma value errors
            double[] firstErrors = min.getBestEstimatesErrors();

            // Get sum of squares
            double ss = min.getSumOfSquares();

            //Calculate new initial estimates
            double[] start2 = new double[this.weibullStandardNumberOfParameters];
            start2[0] = 2.0*firstBests[0] - start[0];
            if(start2[0]>minimum)start2[0] = minimum*(1.0 - Math.abs(minimum)*0.05);
            step[0] = Math.abs(start2[0]*0.1);
            if(step[0]==0)step[0] = this.range*0.01;

            min.simplex(wppf, Conv.copy(start2), step, tolerance);

            // Get gamma for best correlation coefficient
            this.weibullStandardParam = min.getBestEstimates();

            // Get gamma value errors
            this.weibullStandardParamErrors = min.getBestEstimatesErrors();

            // Get sum of squares
            this.weibullStandardSumOfSquares = min.getSumOfSquares();

            // Calculate Weibull Standard order statistic medians
            this.weibullStandardOrderMedians = Stat.weibullOrderStatisticMedians(this.weibullStandardParam[0], this.numberOfDataPoints);

            // Regression of the ordered data on the Weibull order statistic medians
            Regression reg = new Regression(this.weibullStandardOrderMedians, this.sortedData);
            reg.linear();

            // Intercept and gradient of best fit straight line
            this.weibullStandardLine = reg.getBestEstimates();

            // Estimated erors of the intercept and gradient of best fit straight line
            this.weibullStandardLineErrors = reg.getBestEstimatesErrors();

            // Correlation coefficient
            this.weibullStandardCorrCoeff = reg.getSampleR();

            // Initialize data arrays for plotting
            double[][] data = PlotGraph.data(2,this.numberOfDataPoints);

            // Assign data to plotting arrays
            data[0] = this.weibullStandardOrderMedians;
            data[1] = this.sortedData;

            data[2] = weibullStandardOrderMedians;
            for(int i=0; i<this.numberOfDataPoints; i++){
                data[3][i] = this.weibullStandardLine[0] + this.weibullStandardLine[1]*weibullStandardOrderMedians[i];
            }

            // Create instance of PlotGraph
            PlotGraph pg = new PlotGraph(data);
            int[] points = {4, 0};
            pg.setPoint(points);
            int[] lines = {0, 3};
            pg.setLine(lines);
            pg.setXaxisLegend("Weibull Order Statistic Medians");
            pg.setYaxisLegend("Ordered Data Values");
            pg.setGraphTitle("Standard Weibull probability plot:   gradient = " + Fmath.truncate(this.weibullStandardLine[1], 4) + ", intercept = "  +  Fmath.truncate(this.weibullStandardLine[0], 4) + ",  R = " + Fmath.truncate(this.weibullStandardCorrCoeff, 4));
            pg.setGraphTitle2("  mu = 0, sigma = 1, gamma = "  +  Fmath.truncate(this.weibullStandardParam[0], 4));

            // Plot
            pg.plot();

            this.weibullStandardDone = true;
            this.probPlotDone = true;
        }