Sens Slope Estimator Graph

Description:

Sen’s non-parametric estimator of slope is a method of estimating the true slope (change in concentration over time) of the data. If the data show an upward slope, there is evidence of an upward trend. Because this method is non-parametric, it is suitable for a high percentage of non-detects and is not significantly affected by outliers.

This is a graphical display of the non-graphical version of the method. The slope of the line is plotted over the data points in a time-series plot. The slope is calculated using the Sen’s method. The y-intercept is the first data point in the graph. Calculations are displayed in the Calculations tab.

Use:

To estimate the change in concentration over time to determine if there is an upward or downward trend in the data and display the slope as a line on a time-series plot.

Graph Text Placeholders:

You can customize the text that appears on graphs using the following placeholders:

<<Well>> -- The sampling location

<<Parameter>> -- The chemical parameter name

<<AnalysisTitle>> -- The name of the statistical analysis method

<<Facility>> -- The name of the facility (Set from File | Properties)

<<Transformation>> -- The data transformation applied

<<NonDetects>> -- Now non-detects are represented

<<Units>> -- The measurement units

<<MedianQ>> -- The slope calculated by the method