The Median Center feature can be used to find the point that minimizes the total Euclidean distance between all features. The result is a new point, not an object in the source data.
Mean Center and Median Center are both central tendency measures. However, in comparison, Median Center is less sensitive to extreme values (outliers) than Mean Center. For example, the result of a Mean Center calculation for a compact cluster point is a location point at the center of the cluster. If you then add a new point away from the cluster and recalculate the Mean Center, you will notice that the results move closer to the new outlier. If you were to perform the same test using the Median Center tool, you would find that the new outliers have significantly less impact on the location of the results.
Both Median Center and Central Element are to find a point with the least total distance to other elements. The difference is that the result calculated by Central Element must be an original sample in the element sample; What Median Center calculates may not be one of the original elements, but may generate a new position.
Function entrance
- Spatial Statistical Analysis tab-> Measuring Geographic Distributions-> Median Center. （iDesktopX）
- Toolbox-> Spatial Statistical Analysis-> Measuring Geographic Distributions-> Median Center. (iDesktopX)
Main parameters
- Source Data: Set the Vector Dataset to be analyzed, which supports three types of Dataset: point, line and surface. If it is a line or a face, the centroid of the object is taken for calculation, the weight of the point is 1, the weight of the line is the length of the line, and the weight of the face is the area.
- Group Field: a field for classifying analysis elements. After classification, each group of objects will have a Median Center. Group Field can be integer, date or character. If the field value in the Group Field is blank, the element is excluded from the analysis.
- Weight Field: The distance between each element and other elements is weighted. The distance after setting Weight Field is D = W1 X d, where W1 is the weight value and d is the distance between two elements.
- Mean Center: Set Reserved Fields of Result Data and Statistics Type of field value in the field list box.
- Result Settings: Set the Datasource and Dataset Name where the Result Data will be saved.
After setting the above parameters, click the "OK" button in the dialog box to execute the Median Center analysis.
As shown in the figure below, the yellow points are the locations of elephants in a wildlife park in different seasons. By calculating the Median Center points of the location distribution in this area, we can determine where the elephants will gather, so as to provide better Position Info for visitors.
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